ANSI Z49.1:2012 - ABOUT WIM India Private Limited

ANSI Z49.1:2012 - ABOUT WIM India Private Limited
BE SMART – WORK SAFELY FROM THE START
S.NO
TITLE
PAGE NO
1.
SAFETY IN WELDING CUTTING
AND ALLIED PROCESS
1
2.
SAFETY QUICK GUIDE
51
3.
SAFETY AND HEALTH OF
WELDERS
66
4.
INTERNATIONAL STANDARDS
90
5.
WELDING PROCESS GUIDE
110
6.
OXYFUEL SAFETY
124
7.
DIESEL ENGINE SAFETY
129
8.
MIG PARAMETERS
137
SAFETY IN WELDING, CUTTING
AND
ALLIED PROCESSES
Table of Contents
Page No.
Part I—General Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1. Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Scope and Applicability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.3 Exclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.1 Approved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2.2 Confined Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3 Cylinder Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.4 Immediately Dangerous to Life or Health (IDLH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.5 Other Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.6 Qualified Person . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.7 Shall. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.8 Should . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.9 Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.10 Welder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. General Provisions, Management, and Supervision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.1 Setup and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.2 Responsibilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Protection of Personnel and the General Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1 Protection of the General Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.2 Eye and Face Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.3 Protective Clothing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4.4 Noise Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.5 Respiratory Protective Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.6 Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5. Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.2 Breathing Zone Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.3 Avoid the Fume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.4 Types of Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.5 Special Ventilation Concerns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
6. Fire Prevention and Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.1 Areas Containing Combustibles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
6.2 Fire Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
vii
ANSI Z49.1:2012
6.3
6.4
Hot-Work Authorization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Welding or Cutting Containers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7. Confined Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.1 Ventilation in Confined Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
7.2 Location of Service Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7.3 Adjacent Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7.4 Emergency Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7.5 Attendants in Areas Immediately Dangerous to Life or Health (IDLH). . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7.6 Brazing Furnaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
8. Public Exhibitions and Demonstrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
8.1 Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
8.2 Supervision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
8.3 Site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
8.4 Fire Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
8.5 Protection of the Public . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
8.6 Cylinders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
8.7 Process Hoses, Cables, and Conduits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9. Precautionary Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.2 Precautionary Information for Arc Welding and Related Processes and Equipment . . . . . . . . . . . . . . . . . 21
9.3 Precautionary Information for Oxyfuel Gas Processes and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.4 Hazardous Materials Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
9.5 Brazing Filler Metals Containing Cadmium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
9.6 Brazing and Gas Welding Fluxes Containing Fluorides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
9.7 Material Safety Data Sheets (MSDSs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
9.8 Graphic Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
9.9 Hazard Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Part II—Specific Processes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
10. Oxyfuel Gas Welding and Cutting Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
10.1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
10.2 Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
10.3 Oxygen and Combustibles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
10.4 Attachments for Gas Mixing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
10.5 Torches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
10.6 Hose and Hose Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
10.7 Pressure-Reducing Regulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
10.8 Compressed and Oxyfuel Gas Cylinders (Containers) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
10.9 Cylinder Manifolding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
11. Arc Welding and Cutting Equipment Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
11.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
11.2 Safety Aspects in Selection of Arc Welding Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
11.3 Installation of Arc Welding Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
11.4 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
11.5 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
12. Resistance Welding Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
12.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
12.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
12.3 Guarding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
12.4 Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
12.5 Static Safety Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
viii
ANSI Z49.1:2012
12.6 Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
12.7 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
13. Electron Beam Welding and Cutting Processes (EBW and EBC). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
13.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
13.2 Potential Hazards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
14. Laser Beam Cutting and Welding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
14.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
15. Brazing and Soldering Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
15.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
15.2 Potential Hazards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
16. Annex D (Informative)—Master Chart of Welding and Joining Processes and Master Chart of
Allied Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
ix
ANSI Z49.1:2012
List of Tables
Table
1
Page No.
Guide for Shade Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
List of Figures
Figure
1
2
3
4
Page No.
Precautionary Information for Arc Welding Processes and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Precautionary Information for Oxyfuel Gas Processes and Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Precautionary Information for Brazing Filler Metals Containing Cadmium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Precautionary Information for Brazing and Gas Welding Fluxes Containing Fluorides. . . . . . . . . . . . . . . . . . . . 23
x
ANSI Z49.1:2012
Safety in Welding, Cutting, and Allied Processes
(American National Standard Z49.1:2012 uses a two-column format to provide both specific requirements and supporting information. The left column is designated as “Standard Requirements” and the right column is designated as
“Explanatory Information.” The paragraph number of the Explanatory Information is preceded by the letter “E.”)
Standard Requirements
Explanatory Information
Part I
General Aspects
1. Purpose and Scope
1.1 Purpose. This standard is for the protection of
persons from injury and illness and the protection of
property (including equipment) from damage by fire and
explosions arising from welding, cutting, and allied
processes.
E1.1 Beginning with the revision of 1983, the scope of
ANSI Standard Z49.1 has been refocused towards those
safe practices for performing welding, cutting, and allied
processes, which are generally within the implementation
control of the welder or the weld shop management. It is
written in a manner suitable for issuance to the welder
and shop management to give practical information to
help them perform these functions safely. It also contains
information useful to educators, industrial hygienists,
engineers, and similar parties also responsible for safety
and health in welding. With this refocused scope, some
provisions which appeared in prior editions have been
deleted. Those were provisions which dealt more in
matter of building design and construction, facility
pipelines, and electrical installations. Those provisions,
of course, are still important and necessary and must be
followed. They are not provisions usually under the
immediate control of welding and cutting operations.
1.2 Scope and Applicability. This standard shall be for
the guidance of educators, operators, managers, and
supervisors in the safe setup and use of welding and
cutting equipment, and the safe performance of welding
and cutting operations.
E1.2 Specific provisions are included for oxyfuel gas and
arc welding and cutting, resistance welding, electron
beam welding, laser beam cutting and welding, and
brazing and soldering.
However, the requirements of this standard are generally
applicable to the other welding processes such as submerged arc welding and allied processes shown in the
American Welding Society Master Chart of Welding and
Allied Processes, included in Annex D.
1
ANSI Z49.1:2012
1.3 Exclusions. This standard shall not pertain to the
following:
(1) Guidelines for the design or manufacture of
equipment
(2) Building piping systems
(3) Pipeline protection systems and station outlet
equipment
(4) Bulk gas supply systems
(5) Building electrical installations.
E1.3 Some of these were included in former issues of the
standard. These items were eliminated from ANSI Z49.1
to avoid their being included in two separate standards
under separate auspices which can lead to conflict or
confusion between standards.
These are contained in standards and codes of the
National Fire Protection Association (NFPA) as follows:
(1) Oxyfuel gas piping systems, pipeline protective
devices, and station outlet equipment—NFPA 51,
Standard for the Design and Installation of Oxygen-Fuel
Gas Systems for Welding, Cutting, and Allied Processes
(2) Storage and manifolding of multiple gas cylinders—NFPA 51
(3) Acetylene generators and calcium carbide
storage—NFPA 51
(4) Bulk oxygen systems—NFPA 50, Standard for
Bulk Oxygen Systems at Consumer Sites
(5) Bulk LP-Gas and MPS systems—NFPA 58,
Storage and Handling of Liquefied Petroleum Gases
(6) Building electrical installations—NFPA 70,
National Electrical Code®
(7) Industrial machinery—NFPA 79, Electrical
Standard for Industrial Machinery
1.4 Equivalency. Nothing in this standard is intended to
prevent the use of systems, methods, or devices of
equivalent or superior quality, strength, fire resistance,
effectiveness, durability, and safety over those prescribed
by this standard.
1.4.1 Technical documentation shall be submitted to
the authority having jurisdiction to demonstrate
equivalency.
1.4.2 The system, method, or device shall be approved
for the intended purpose by the authority having
jurisdiction.
2. Definitions
The following definitions shall apply to this standard.
2.1 Approved. Approved and approval as used in this
standard mean acceptable to the authority having
jurisdiction.
2.1.1 Authority Having Jurisdiction. This term
refers to the organization, office, or individual
responsible for “approving” equipment, an installation,
or a procedure.
2.1.2 Listed. This term means the equipment or
material included in a list published by a nationally
recognized testing laboratory that maintains periodic
inspection of production of listed equipment or materials.
2
ANSI Z49.1:2012
2.2 Confined Space. Refers to a relatively small or
restricted space such as a tank, boiler, pressure vessel, or
small compartment. Confinement implies poor
ventilation as a result of construction, size, or shape
rather than restriction of egress of personnel.
E2.2 For additional information, see ANSI Z117.1,
Safety Requirements for Confined Spaces, and applicable
OSHA standards 29 CFR 1910.145 for General Industry,
29 CFR 1926.353(b) for Construction, and 29 CFR 1915
subpart B for Maritime.
2.3 Cylinder Storage. Refers to cylinders of
compressed gas standing by on the site (not those in use
or attached ready for use).
2.3.1 Cylinders in Use. This term refers to the
following:
(1) Cylinders connected for use;
(2) A single cylinder for each gas to be used, in the
use location, ready to be connected; or
(3) A one day supply of cylinders, in the use location,
ready to be connected.
2.4 Immediately Dangerous to Life or Health
(IDLH). IDLH is a condition which poses an immediate
threat of loss of life; may result in irreversible or
immediate severe health effects, or other conditions
which could impair escape.
2.5 Other Definitions. All other welding terms used
herein are in accordance with the current edition of AWS
A3.0M/A3.0, Standard Welding Terms and Definitions.
2.6 Qualified Person. A person who by reason of
training, education, and experience is knowledgeable in
the operation to be performed and is competent to judge
the hazards involved.
2.7 Shall. Shall is used to indicate provisions which are
mandatory.
2.8 Should. Should or it is recommended that is used to
indicate provisions which are not mandatory.
2.9 Unit. Numerical values are given in U.S. customary
and metric (SI) units.
E2.10 This term also includes educators and students that
are engaged in similar activities.
2.10 Welder. “Welder” and “welding operator” as used
herein are intended to designate any operator of electric
or oxyfuel gas welding or cutting equipment, or allied
processes.
3. General Provisions, Management,
and Supervision
3.1 Setup and Installation
3.1.1 Equipment and Condition Maintenance. All
welding and cutting equipment shall be inspected as
required to assure it is in safe operating condition. When
found to be incapable of reliable safe operation, the
equipment shall be repaired by qualified personnel prior
to its next use or withdrawn from service.
3
ANSI Z49.1:2012
3.1.2 Operation. All equipment shall be operated in
accordance with manufacturers’ recommendations and
instructions, provided these are consistent with this
standard.
E3.1.2 Most manufacturers provide safety
information along with operational and maintenance
information. Operators should become familiar with, and
follow, that safety information.
3.1.3 Heavy Portable Equipment on Wheels.
Heavy portable equipment mounted on wheels shall be
secured in position to prevent accidental movement
before operations are started.
E3.1.3 See 7.2.2 for additional information.
3.2 Responsibilities. Operators and management shall
recognize their mutual responsibilities for safety in
welding and cutting.
3.2.1 Management
E3.2.1 Management, as used in this standard, includes
all persons who are responsible for welding operations
such as owners, contractors, educators, and others.
3.2.1.1 Training. Management shall assure that
welders and their supervisors are trained in the safe
operation of their equipment, the safe use of the process,
and emergency procedures.
3.2.1.2 Hazard Communication. Management
shall assure that hazards and safety precautions are
communicated to and understood by workers prior to the
start of work.
E3.2.1.2 The hazards which may be involved in
welding are communicated to users through manufacturers’
instructions, material safety data sheets, and product
labeling. See Clause 9, Precautionary Information, of this
standard. See especially OSHA 29 CFR, Section
1910.1200, Hazard Communication Standard.
3.2.1.3 Designated Areas and Responsibilities.
Management shall designate approved areas, and
establish procedures for safe welding and cutting.
E3.2.1.3 See 6.3 for additional information.
A designated management representative shall be responsible for authorizing welding and cutting operations in
areas not specifically designed or approved for such
processes. Management shall assure that the individual is
aware of the hazards involved and familiar with the provisions of this standard.
3.2.1.4 Approved Equipment. Management shall
assure that only approved apparatus, such as torches,
manifolds, regulators, pressure reducing valves, acetylene
generators, welding machines, electrode holders, and
personal protective devices are used.
3.2.1.5 Contractors. Management shall select
contractors to perform welding who provide trained and
qualified personnel, and who have an awareness of the
risks involved.
E3.2.1.5 For the purposes of this standard, in
contract operations, the responsibility for the welder rests
with the contractor supervisor and the contractor
management.
Management shall advise contractors about flammable
materials or hazardous conditions that are specific to the
job site.
Management shall advise contractors about flammable
materials or hazardous conditions of which they may not
be aware.
4
ANSI Z49.1:2012
3.2.2 Supervisors
E3.2.2 Supervisors, as used in this standard, include
all persons who are responsible for supervising welding
operations such as owners, contractors, educators, and
others.
3.2.2.1 Safe Use of Equipment. Supervisors shall
be responsible for the safe handling of the welding
equipment and for the safe use of the welding process.
3.2.2.2 Fire Hazards. Supervisors shall determine
what flammable and combustible materials are present or
likely to be present in the work location. They shall
ensure that such materials are not exposed to ignition by
taking one or more of the following actions:
(1) Have the work moved to a location free from
combustibles and away from hazardous areas.
(2) Have the combustibles moved a safe distance
from the work or properly shielded against ignition if the
work cannot readily be moved.
(3) Schedule welding and cutting so that such materials are not exposed during welding and cutting operations.
E3.2.2.2 See also Clause 6, Fire Prevention and
Protection.
3.2.2.3 Authorization. Authorization for the
welding or cutting operations shall be obtained from
the designated management representative prior to the
commencement of hot work or entering a confined space.
Supervisors shall oversee that the welder has approval
that conditions are safe before going ahead.
E3.2.2.3 See 6.3 and 7.1. There are some
circumstances where the authorization must be written;
for example, permit-required confined space entry. See
especially OSHA 29 CFR, Section 1910.146, PermitRequired Confined Space Standard.
3.2.2.4 Protective
Equipment
and
Fire
Protection. Supervisors shall assure that proper personal
protective and fire protection equipment is used. They
shall assure that fire protection and fire extinguishing
equipment are properly located at the site, and that fire
watchers are assigned and hot-work authorization
procedures are followed where required.
E3.2.2.4 See 6.2, 6.3, and 6.4.
The inspection is usually made one-half hour after the
completion of welding operations to detect and extinguish possible smoldering fires. Be alert for circumstances which may require an extension of the final
inspection interval.
Where fire watchers are not required, a final inspection
shall be made by supervision.
3.2.3 Welders
3.2.3.1 Safe Handling of Equipment. Welders
shall understand the hazards of the operation to be
performed and the procedures being used to control
hazardous conditions. Welders shall handle the
equipment safely and use it so as not to endanger lives
and property.
E3.2.3.1 Welders make the final choice to weld or
not to weld. They need to understand the hazards before
proceeding.
3.2.3.2 Permission. Welders shall have permission
of management before starting to weld or cut. Welders
shall continue to weld or cut only so long as conditions
are unchanged from those under which permission was
granted.
E3.2.3.2 See 6.3. In many facilities, management
grants blanket permission for cutting and welding where
fire hazards are not present.
3.2.3.3 Safe Conditions. Welders shall cut or
weld only where all safety precautions have been met.
E3.2.3.3 Do not work alone where conditions are
especially hazardous, such as where electric shock is a
hazard, or where ventilation is poor, etc.
5
ANSI Z49.1:2012
3.2.3.4 Marking Hot Materials. Where others
may unknowingly come in contact with hot material
remaining from welding, a notice shall be posted.
4. Protection of Personnel and the
General Area
4.1 Protection of the General Area
4.1.1 Equipment. Welding equipment, machines,
cable, and other apparatus shall be located so that it does
not present a hazard to personnel. Good housekeeping
shall be maintained.
E4.1.1 For example, locations such as passageways,
ladders, or stairways should be kept clear.
4.1.2 Signs. Signs shall be posted designating
welding areas, and indicating that eye protection and
other applicable protective devices shall be worn.
E4.1.2 Additional precautionary information should
be posted when circumstances present additional hazards.
4.1.3 Protective Screens. Workers or other persons
adjacent to the welding areas shall be protected from the
radiant energy and spatter of welding and cutting by
noncombustible or flame-resistant screens or shields, or
shall be required to wear eye and face protection, and
protective clothing.
E4.1.3 Radiation-protective, semitransparent materials
are permissible. Screens should permit circulation of air at
floor level as well as above the screen. Refer to NFPA
701, Standard Methods of Fire Tests for Flame
Propagation Textiles and Films, for information on
ignition resistance criteria. For additional information on
radiation protection, see 4.2.2. The intensity of arc radiant
energy depends on many factors, including current,
voltage, and the materials employed. Refer to 4.2.2.
4.1.4 Reflectivity. Where arc welding is regularly
carried out, adjacent walls and other surfaces shall have
low reflectivity to ultraviolet radiation.
E4.1.4 Finishes formulated with pigments such as
titanium dioxide or zinc oxide have low reflectivity to
ultraviolet radiation. Color pigments may be added if
they do not increase reflectivity. Lamp black has been
recommended as a paint additive in the past, but it
reduces visible light and is accordingly less desirable in
view of the need for good lighting as well as ultraviolet
radiation absorption.
Pigments based on powdered or flaked metals are not recommended because of their high reflectivity of ultraviolet
radiation.
Welding curtains are another means of reducing reflectivity. For further guidance, see Ultraviolet Reflectance of
Paint, published by and available from the American
Welding Society.
4.1.5 Welding Booths. Where operations permit,
welding stations shall be separated by noncombustible
screens or shields with characteristics as described in
4.1.3.
4.2 Eye and Face Protection. Eye and face protection
shall comply with ANSI/ISEA Z87.1, Occupational
and Educational Personal Eye and Face Protection
Devices.
6
ANSI Z49.1:2012
4.2.1 Type Selection
E4.2.1.1 Welding helmets with filter lenses are
intended to protect users from arc rays and from weld
sparks and spatter which impinge directly against the
helmet. To protect the user from impact hazards when the
welding helmet may be raised during use, spectacles with
lateral protection or goggles should also be worn.
4.2.1.1 Arc Welding and Arc Cutting with Open
Arcs. Helmets or hand shields with filter lenses and cover
lenses shall be used by operators and nearby personnel
when viewing the arc.
Protective spectacles with side shields, arc goggles, or
other approved eye protection shall also be worn.
The spectacles or goggles may have either clear or filtered lenses, depending upon the amount of exposure to
adjacent welding or cutting radiation (see Table 1).
Others in the immediate welding area should wear similar
eye protection. Welding helmets will not protect against
the severe impact of fragmenting grinding wheels, abrasive discs, or explosive devices.
4.2.1.2 Oxyfuel Gas Welding and Cutting and
Submerged Arc Welding. Welding goggles, or welding
helmet or welding faceshield over spectacles or goggles
shall be worn during all oxyfuel gas welding and cutting,
and submerged arc welding operations.
E4.2.1.2 It is recommended that such eye
protection offer lateral (side) coverage. (See Table 1.)
4.2.1.3 Resistance Welding and Brazing.
Operators of resistance welding or brazing equipment
and their helpers shall wear welding goggles, or welding
helmet or welding faceshield over spectacles or goggles
for eye and face protection.
4.2.1.4 Large Area Viewing. For large area
viewing, such as training, demonstrations, shows, and
certain automatic welding operations, a large filter
window or curtain shall be permitted to be used in lieu of
eye and face protection. The radiation transmission of
window or curtain material shall be equivalent to that in
ANSI/ISEA Z87.1 for shade number appropriate to the
welding or cutting operation.
Additionally, suitable arrangements shall be provided to
prevent direct viewing of the arc without filter protection
and to protect viewers from sparks and chipped slag.
4.2.2 Requirements for Eye and Face Protection
4.2.2.1 Filter Lenses. Filter lenses shall be in
accordance with ANSI/ISEA Z87.1, and the shade shall
be selected in accordance with AWS F2.2, Lens Shade
Selector, or Table 1.
E4.2.2.1 See latest edition of AWS F2.2. Filter
lenses should be free from any flaws which may distract,
block, or otherwise impair vision.
4.2.2.2 Material Properties. Helmet and hand
shield bodies shall be made of material that is thermally
and electrically insulating, noncombustible or selfextinguishing, and opaque to visible, ultraviolet, and
infrared radiation, and shall comply with the requirements
of ANSI/ISEA Z87.1, Occupational and Educational
Personal Eye and Face Protection Devices.
E4.2.2.2 Welding helmets, hand shields, and
goggles complying with ANSI/ISEA Z87.1 are limited in
combustibility.
Persons with special eye conditions should consult their
physician for specific information on protective equipment.
7
ANSI Z49.1:2012
Table 1
Guide for Shade Numbers
(from AWS F2.2:2001(R2010), Lens Shade Selector)
Shade numbers are given as a guide only and may be varied to suit individual needs.
Suggesteda
Shade No.
(Comfort)
Electrode Size
in (mm)
Arc Current
(Amperes)
Minimum
Protective
Shade
Less than 3/32 (2.4)
3/32–5/32 (2.4–4.0)
5/32–1/4 (4.0–6.4)
More than 1/4 (6.4)
Less than 60
60–160
160–250
250–550
7
8
10
11
—
10
12
14
Gas Metal Arc Welding
(GMAW) and Flux Cored Arc
Welding (FCAW)
Less than 60
60–160
160–250
250–500
7
10
10
10
—
11
12
14
Gas Tungsten Arc Welding
(GTAW)
Less than 50
50–150
150–500
8
8
10
10
12
14
Air Carbon Arc (Light)
Cutting (CAC-A) (Heavy)
Less than 500
500–1000
10
11
12
14
Plasma Arc Welding (PAW)
Less than 20
20–100
100–400
400–800
6
8
10
11
6 to 8
10
12
14
Plasma Arc Cutting (PAC)
Less than 20
20–40
40–60
60–80
80–300
300–400
400–800
4
5
6
8
8
9
10
4
5
6
8
9
12
14
Torch Brazing (TB)
—
—
3 or 4
Torch Soldering (TS)
—
—
2
Carbon Arc Welding (CAW)
—
—
14
Process
Shielded Metal
Arc Welding (SMAW)
in
mm
Suggesteda
Shade No.
(Comfort)
Under 1/8
1/8 to 1/2
Over 1/2
Under 3
3 to 13
Over 13
4 or 5
5 or 6
6 or 8
Under 1
1 to 6
Over 6
Under 25
25 to 150
Over 150
3 or 4
4 or 5
5 or 6
Plate Thickness
Oxyfuel Gas Welding (OFW)
Light
Medium
Heavy
Oxygen Cutting (OC)
Light
Medium
Heavy
a
As a rule of thumb, start with a shade that is too dark to see the weld zone. Then go to a lighter shade which gives sufficient view of the weld zone
without going below the minimum. In oxyfuel gas welding, cutting, or brazing where the torch and/or the flux produces a high yellow light, it is desirable to use a filter lens that absorbs the yellow or sodium line of the visible light spectrum.
8
ANSI Z49.1:2012
4.2.2.3 Area of Protection. When there is a
possibility of hazardous exposure, helmets and hand
shields shall protect the face, forehead, neck, and ears to
a vertical line in back of the ears, from direct radiant
energy from the arc, and from direct weld spatter.
E4.2.2.3 Some low current processes, such as with
micro Plasma Arcs, may not present a hazardous
radiation exposure, but may have a spatter exposure.
Therefore, operators should be provided with safety
glasses even if there is no radiation hazard.
4.2.2.4 Effect of Materials on Skin. Materials in
contact with the body shall not readily irritate or discolor
the skin.
4.2.2.5 Goggle Ventilation. Goggles shall be
vented to deter fogging of the lenses in accordance with
ANSI Z87.1.
4.2.2.6 Outer Cover Lenses. Outer lenses shall be
provided to protect the filter lens or filter lens in goggles,
helmets, or hand shields from welding spatter, pitting, or
scratching. Outer cover lenses shall be of clear glass or
self-extinguishing plastic, but need not be impact resistant.
4.2.2.7 Inner Lenses or Plates. When the “lift
front” type of welders’ helmet is used, there shall be a
fixed impact resistant safety lens or plate on the inside of
the frame nearest to the eyes to protect the welder against
flying particles when the front is lifted.
4.2.2.8 Marking. Filter lenses shall bear some
permanent distinctive marking by which the manufacturer
may be readily identified. In addition, all filter lenses shall
be marked with their shade number and in accordance
with the requirements of ANSI Z87.1.
4.2.2.9 Radiation Transmittance Properties. All
filter lenses shall meet the “Ultraviolet, Luminous and
Infrared Transmittance” requirements of ANSI Z87.1.
4.2.2.10 Maintenance. Helmets, handshields, and
goggles shall be well maintained, and should not be
transferred from one employee to another without being
cleaned.
E4.2.2.10 For methods of cleaning, refer to the
manufacturer’s instructions.
4.3 Protective Clothing. Clothing shall be selected to
minimize the potential for ignition, burning, trapping hot
sparks, or electric shock.
E4.3 Heavier materials such as woolen clothing or heavy
cotton are preferable to lighter materials because they are
more difficult to ignite. Cotton clothing, if used for
protection, should be chemically treated to reduce its
combustibility. Clothing treated with flame resistant
materials may lose some of its protective characteristics
after repeated washing or cleaning. Materials which can
melt and cause severe burns should not be used as
clothing when welding or cutting.
Sparks may lodge in rolled-up sleeves, pockets of clothing,
or cuffs of overalls or trousers. It is therefore recommended
that sleeves and collars be kept buttoned and pockets be
eliminated from the front of clothing. When pockets are present, they should be emptied of flammable or readily combustible materials. Trousers or overalls should not have cuffs
and should not be turned up on the outside. Trousers should
overlap shoe tops to prevent spatter from getting into shoes.
9
ANSI Z49.1:2012
Frayed clothing is particularly susceptible to ignition and
burning and should not be worn when welding or cutting.
Refer to 11.3 and 11.4.
4.3.1 Selection. Clothing shall provide sufficient
coverage, and be made of suitable materials, to minimize
skin burns caused by sparks, spatter, or radiation.
E4.3.1 Appropriate protective clothing for any
welding and cutting operation will vary with the size,
nature, and location of the work to be performed.
Clothing should be kept clean, as oil and grease can
reduce its protective qualities.
4.3.2 Gloves. All welders and cutters shall wear
protective flame-resistant gloves. All gloves shall be in
good repair, dry, and capable of providing protection
from electric shock by the welding equipment.
E4.3.2 Gloves made of leather, rubber, or other
suitable materials are recommended. Insulating linings
should be used to protect areas exposed to high radiant
energy. See E11.2.2.
4.3.4 Leggings. For heavy work, flame-resistant
leggings or other equivalent means shall be used to give
added protection to the legs, when necessary.
E4.3.4 In production work, a sheet metal screen in
front of the worker’s legs can provide further protection
against sparks and molten metal in cutting operations.
4.3.5 Capes and Sleeves. Cape sleeves or shoulder
covers with bibs made of leather or other flame-resistant
material shall be worn during overhead welding, cutting,
or other operations, when necessary.
4.3.6 Other Protective Clothing. Properly fitted
flame-resistant plugs in the ear canals, or equivalent
protection, shall be used where hazards to the ear canals
exist.
Caps made from flame resistant material shall be worn
under helmets, when necessary, to prevent head burns.
4.4 Noise Control. Noise shall be controlled at the source
when feasible. When control methods fail to bring noise
exposure within allowable limits, personal protective
devices such as ear muffs or ear plugs shall be used.
E4.4 In welding, cutting, and allied operations, noise
results from the process and from the equipment. Processes
that may produce high noise levels are air carbon arc
cutting and gouging, and plasma arc cutting and gouging,
plus some oxyfuel processes and equipment, and support
equipment.
Equipment which sometimes have a high noise level are
engine driven generators. Other equipment and processes,
such as chipping and grinding, may produce hazardous
noise exposure, depending on specific circumstances.
4.5 Respiratory Protective Equipment. When controls
such as ventilation fail to reduce air contaminants to
allowable levels or when the implementation of such
controls are not feasible, respiratory protective equipment
shall be used to protect personnel from hazardous
concentrations of airborne contaminants.
E4.5 See 5.1 for a discussion of allowable levels. For
guidance on use of respirators in confined spaces, refer to
Clause 7, Confined Spaces, of this standard.
4.5.1 Only approved respiratory protective equipment
shall be used.
E4.5.1 Approvals of respiratory equipment are issued
by the National Institute for Occupational Safety and
Health (NIOSH) or the Mine Safety and Health
Administration (MSHA).
4.5.2 Whenever the use of respirators is required, a
program to establish the proper selection and use of
respirators shall be implemented.
E4.5.2 Federal regulations for respirator use dictate
that respirators not be passed from one employee to
another without being sanitized per OSHA 29 CFR,
Section 1910.134, Respiratory Protection Standard.
10
ANSI Z49.1:2012
4.5.3 Compressed air for air supplied respirators or
other breathing equipment shall at least meet the Grade D
requirements of the Compressed Gas Association
ANSI/CGA G-7.1, Commodity Specification for Air.
E4.6 Persons include workers and their immediate
supervisors. See appropriate ANSI standards on
protective clothing and equipment.
4.6 Training. Persons exposed to welding hazards shall
be trained in the use of, and understand the reasons for,
protective clothing and equipment.
5. Ventilation
E5.1 The factors for determining adequate ventilation
include the following:
(1) Volume and configuration of the space in which
operations occur (see Clause 7, Confined Spaces)
(2) Number and type of operations generating contaminants
(3) Concentrations of specific toxic or flammable
contaminants being generated (see 5.2)
(4) Natural air flow (rate and general atmospheric
conditions where work is being done)
(5) Location of the welder’s and other person’s
breathing zones in relation to the contaminants or sources
5.1 General. Adequate ventilation shall be provided for
all welding, cutting, brazing, and related operations.
Adequate ventilation shall be enough ventilation such that
personnel exposures to hazardous concentrations of
airborne contaminants are maintained below the allowable
limits specified by the authority having jurisdiction.
Respiratory protective equipment as specified in 4.5 shall
be used when adequate ventilation is not practical.
In cases where the values for allowable exposure limits vary
among recognized authorities, the lower values should be
used to effect the maximum personnel protection.
Fumes and gases from welding and cutting cannot be
classified simply. The composition and quantity of fumes
and gases are dependent upon the metal being worked,
the process and consumables being used, coatings on the
work such as paint, galvanizing, or plating, contaminants
in the atmosphere such as halogenated hydrocarbon
vapors from cleaning and degreasing activities, as well as
the factors itemized in this section for adequate ventilation. A good practice to reduce the generation of fumes
and gases from paints and primers is to grind or sand the
surface to bare metal prior to welding. Note however that
the method of removal may generate particulates that
require worker protection.
In welding and cutting, the composition of the fumes is
usually different from the composition of the electrode or
consumables.
Reasonably expected fume products of normal operation
include those originating from consumables, base metals
and coating, and the atmospheric contaminants noted.
Reasonably expected gaseous products include carbon
monoxide, carbon dioxide, fluorides, nitrogen oxides,
and ozone.
The recommended way to determine adequate ventilation
is to sample for the composition and quantity of fumes
and gases to which personnel are exposed (see 5.2).
11
ANSI Z49.1:2012
The Occupational Safety and Health Administration
(OSHA) or others may be the authority having jurisdiction.
Although not an authority having jurisdiction, many of
these exposure limits are adopted from the publications
of the American Conference of Governmental Industrial
Hygienists (ACGIH). Refer to E4.1.3, Protective
Screens, and Clause 7, Confined Spaces.
5.2 Breathing Zone Sampling. Where concentrations of
airborne fume contaminants are to be determined by
sampling of the atmosphere, sampling shall be in
accordance with AWS F1.1, Method for Sampling
Airborne Particulates Generated by Welding and Allied
Processes. When a helmet is worn, the samples shall be
collected inside the helmet in the welder’s breathing zone.
5.3 Avoid the Fume. Welders and cutters shall take
precautions to avoid breathing the fume directly.
E5.3 Avoiding the fume can be done by positioning of the
work, the head, or by ventilation which captures or directs
the fume away from the face. Tests have shown that fume
control is more effective when the air flow is directed
across the face of the welder, rather than from behind.
Most of the fume appears as a clearly visible plume which
rises directly from the spot of welding or cutting.
5.4 Types of Ventilation. If natural ventilation is not
sufficient to maintain contaminants below the allowable
limits referenced in 5.1, mechanical ventilation or
respirators shall be provided.
E5.4 Natural ventilation is acceptable for welding,
cutting, and related processes where the necessary
precautions are taken to keep the welder’s breathing zone
away from the fumes and where sampling of the
atmosphere shows that concentration of contaminants are
below the allowable limits referenced in 5.1.
Mechanical ventilation includes local exhaust, local
forced air, and general area mechanical air movement.
Local exhaust ventilation is preferred.
Local exhaust ventilation means fixed or moveable
exhaust hoods placed as near as practicable to the work
and able to maintain a capture velocity sufficient to keep
airborne contaminants below the allowable limits referenced in 5.1. Local forced ventilation means a local air
moving system (such as a fan) placed so that it moves the
air horizontally across the welder’s face. General
mechanical ventilation may be necessary in addition to
local forced ventilation.
Examples of general mechanical ventilation are roof
exhaust fans, wall exhaust fans, and similar large area air
movers.
General mechanical ventilation is not usually as satisfactory for health hazard control as local mechanical ventilation. It is often helpful, however, when used in addition to
local ventilation.
Ventilation should not produce more than approximately
100 feet per minute (0.5 meters per second) air velocity at
the work (welding or cutting) zone. This is to prevent disturbance of the arc or flame. It should be recognized that
12
ANSI Z49.1:2012
approximately 100 feet per minute (0.5 meters per second) air velocity is a recommended maximum value for
quality control purposes in welding and cutting. It is not
intended to imply adequacy in contaminant control for
worker health protection.
5.4.1 Recirculation. Precautions shall be taken to
ensure that excessive levels of contaminants are not
dispersed to other work areas. When air is recirculated,
the buildup of the contaminants beyond allowable limits
referred to in 5.1 shall be prevented. Manufacturer’s
precautions pertaining to consumables and processes
shall be observed.
5.4.2 Air Cleaners. Air cleaners shall be used only if
it has been determined by atmospheric sampling that they
maintain the level of hazardous contaminants below the
allowable limits referred to in 5.1.
E5.4.2 Air cleaners are devices which circulate
contaminated air through filters and return the filtered air
to the ambient environment.
The devices reduce the amount of air exhausted to the
outdoors and reduce make-up air requirements. Most filters do not remove gases. Therefore, adequate monitoring
must be done to assure concentrations of harmful gases
remain below allowable limits.
5.5 Special Ventilation Concerns
E5.5.1 Certain materials, sometimes contained in the
consumables, base metals, coatings, or atmospheres of
welding or cutting operations, have very low allowable
limits.
5.5.1 Low Allowable-Limit Materials. Whenever the
following materials are identified as other than trace
constituents in welding, brazing, or cutting operations, and
unless breathing zone sampling under the most adverse
conditions has established that the level of hazardous
constituents is below the allowable limits of 5.1, the special
ventilation precautions given in 5.5.1.1 and 5.5.1.2 shall be
taken: Antimony, Arsenic, Barium, Beryllium Cadmium,
Chromium, Cobalt, Copper, Lead, Manganese, Mercury,
Nickel, Ozone, Selenium, Silver, Vanadium.
Refer to material safety data sheets provided by the manufacturer to identify any of the materials listed here.
5.5.1.1 Confined Spaces. Whenever materials
exceed the allowable limits referred to in 5.5.1 in
confined space operations, local exhaust mechanical
ventilation and, when required, respiratory protection
shall be used (see also Clause 7).
5.5.1.2 Adjacent Persons. All persons in the
immediate vicinity of welding or cutting operations
involving the materials listed in 5.5.1 shall be similarly
protected.
E5.5.2 Fumes and gases from fluorine compounds can
be dangerous to health and can burn eyes and skin on
contact. See 9.6 for labeling of brazing and gas welding
fluxes containing fluorides.
5.5.2 Fluorine Compounds. In confined spaces,
when welding or cutting operations involve fluxes,
coatings, or other materials that contain fluorine
compounds, local exhaust mechanical ventilation or
respiratory protection shall be provided.
In open spaces, when welding or cutting involves materials containing fluorine compounds, the need for local
exhaust ventilation or respiratory protection will depend
upon the individual circumstances. However, experience
has shown that such protection is desirable for fixed location production welding and for all production welding
13
ANSI Z49.1:2012
on stainless steels. Such protection is not necessary when
air samples taken in breathing zones indicate that the fluorides liberated are below allowable limits.
5.5.3 Zinc or Copper. Welding or cutting operations
involving consumables, base metals, or coatings
containing zinc or copper shall be done as described in
5.5.2 for fluorine compounds.
E5.5.3 Fumes containing zinc or copper compounds
may produce symptoms of nausea, dizziness, or fever,
sometimes called “metal fume fever.”
5.5.4 Cleaning Compounds. When using cleaning
compounds prior to welding, manufacturers’ instructions
shall be followed.
E5.5.4.1 A reaction product having a characteristic
objectionable, irritating odor, and including highly toxic
phosgene gas is produced when such vapors enter the
atmosphere of arc welding operations. Low levels of
exposure can produce feeling of nausea, dizziness, and
malaise. Heavy exposures may produce serious health
impairments.
5.5.4.1 Chlorinated Hydrocarbons. Degreasing or
cleaning operations involving chlorinated hydrocarbons
shall be so located that vapors from these operations will
not reach or be drawn into the atmosphere surrounding
molten weld metal or the arc.
In addition, these materials shall be kept out of atmospheres penetrated by the ultraviolet radiation of arc
welding operations.
5.5.5 Arc and Gas Cutting. Oxygen cutting using
either a chemical flux or iron powder, gas-shielded arc
cutting, or plasma cutting shall be done using local
mechanical ventilation or other means adequate to
remove the fumes generated.
E5.5.5 Use of water tables, water curtains, underwater
cutting, ventilation or combination of these will depend
upon the individual circumstances. Experience has
shown that such protection is desirable for fixed location
production welding and for all production welding on
stainless steels. Such protection is not necessary when air
samples taken in breathing zones indicate that the
materials liberated are below allowable limits.
5.5.6 Brazing Furnaces. In all cases, adequate
mechanical ventilation shall be provided to remove all
explosive or toxic gases which may emanate from
furnace purging and brazing operations.
E5.5.6 Where complete combustion takes place in or
at the furnace during the heating cycle, the ventilation
requirement may diminish.
5.5.7 Asbestos. Where welding or cutting is to be
done on surfaces that are covered by asbestos insulation,
the regulations of the authority having jurisdiction shall
be consulted before beginning the work.
E5.5.7 Protection of the employees in the area may
require training, respiratory protection, wetting down the
asbestos, and use of special protective clothing in addition
to special ventilation. See also OSHA asbestos standards.
6. Fire Prevention and Protection
E6. Fire Prevention
For more information on the following precautions, as well
as on the fire protection and prevention responsibilities of
welders, supervisors (including outside contractors), and
management, see NFPA 51B, Standard for Fire
Prevention During Welding, Cutting, and Other Hot Work.
6.1 Areas Containing Combustibles
E6.1 Welding and cutting should preferably be done in
specially designated areas which have been designed and
constructed to minimize fire risk. Good housekeeping
should be maintained.
6.1.1 Conditions for Cutting or Welding. No
welding or cutting shall be done unless the atmosphere is
nonflammable and unless combustibles are moved away
or protected from fire hazards.
14
ANSI Z49.1:2012
6.1.2 Work Movable. Where practical, the work
shall be moved to a designated safe location.
6.1.3 Fire Hazards Movable. Where it is not
practical to move the work, all movable nearby fire
hazards shall be relocated to a safe location.
6.1.4 Work and Fire Hazards Immovable. Where
the work and fire hazards are not movable, safeguards
shall be used to protect the immovable fire hazards and
nearby personnel from the heat, sparks, and slag.
6.1.4.1 Combustible Floors. Combustible floors
shall be clean and protected by wetting with water or
covering with damp sand, sheet metal, or the equivalent.
Provisions shall be taken to protect personnel from electric
shock when floors are wet. Exception: Wood floors laid
directly on concrete shall not be required to be wetted.
6.1.4.2 Nearby Openings. All cracks or openings
in the floor shall be covered or closed or precautions shall
be taken to protect flammable or combustible materials
on the floor below from sparks which might drop through
the openings. The same precautions shall be observed
with regard to cracks or openings in walls, open
doorways, or open or broken windows.
6.2 Fire Protection
6.2.1 Extinguishers and Sprinklers
6.2.1.1 Sufficient fire extinguishing equipment
shall be ready for use where welding and cutting work is
being done. Permissible fire extinguishing equipment
shall be pails of water, buckets of sand, hose, or portable
extinguishers, depending upon the nature and quantity of
combustible material exposed.
6.2.1.2 Where sprinkler system protection exists, it
shall remain operable during the welding or cutting.
Automatic sprinkler heads in the immediate vicinity of
the welding shall be permitted to be temporarily shielded
with noncombustible sheet material or damp cloth guards
where they could be activated by the heat of the welding
process.
E6.2.2 Fire watchers are persons assigned to work
with welders, to watch for fires resulting from welding,
cutting, and brazing operations. When welding or cutting
at elevated positions, care should be taken to protect
against falling sparks and spatter. Accumulations of dust
may be ignited by sparks or spatter, and carry a fire to
other locations.
6.2.2 Fire Watchers. Fire watchers shall be qualified
individuals, knowledgeable about fire reporting procedures,
and emergency rescue procedures, who are assigned duties
to detect and prevent spread of fires. Fire watchers shall be
posted where welding or cutting is done and where a large
fire might develop, or whenever any of the following
conditions exist:
(1) Proximity of Combustibles. Combustible materials
in building construction or contents are closer than a
radius of 35 feet (10.7 meters) to the point of operation.
(2) Openings. There are wall or floor openings within
a radius of 35 feet (10.7 meters) which expose combustible
Fire watchers normally would watch for fires in areas not
readily observed by the welder, such as on opposite sides
of walls, levels below, or hidden areas, or to observe in an
area after the welder has left.
15
ANSI Z49.1:2012
material in adjacent areas, including concealed spaces in
walls, ceilings or floors.
(3) Metal Walls and Pipes. Combustible materials
adjacent to the opposite side of metal partitions, walls,
ceilings, or roofs, or in contact with pipes, and are likely
to be ignited by conduction or radiation.
(4) Ship Work. Ship work performed on opposite sides
of tank shells, decks, overheads, and bulkheads, where
direct penetration of sparks or heat transfer in welding
may introduce a fire hazard to an adjacent compartment.
Processes such as air carbon arc cutting and plasma arc
cutting can cause sparks to travel in excess of 35 feet
(10.7 meters).
In Canada, the recommended distance is 50 feet
(15 meters).
6.2.3 Additional Fire Watchers. Where it is
necessary to observe areas that are hidden from the view
of a single fire watcher (other side of partitions, walls,
ceilings, etc.) additional fire watchers shall be posted.
E6.2.4 The duration of fire watch should be extended
until the hazard of fire no longer exists. Be alert,
combustibles such as wood dust can smolder for extended
periods of time (days). See NFPA Fire Protection
Handbook, 20th edition, clause 9, page 5.
6.2.4 Fire Watch Duties. Fire watchers shall be
trained in the use of fire extinguishing equipment. They
shall be familiar with facilities for sounding an alarm in
the event of a fire, and shall remain outside of any
confined space to be in communication with those
working inside.
They shall watch for fires in all exposed areas, try to
extinguish them only when obviously within the capacity
of the equipment available, or otherwise sound the alarm.
A fire watch shall be maintained for at least one-half hour
after completion of welding or cutting operations to
detect and extinguish possible smoldering fires. Fire
watchers shall be permitted to have additional duties;
however, these additional duties shall not distract them
from their fire watcher responsibilities.
6.3 Hot-Work Authorization. Before welding or
cutting is begun in a location not designed for such
purposes, inspection and authorization by a designated
management representative shall be required.
E6.3 Hot work is any work involving burning, welding, or
similar operations capable of initiating fires or explosions.
Authorization is usually in the form of a written permit.
See NFPA 51B for an example of a hot-work permit.
6.4 Welding or Cutting Containers. Welding or
cutting work shall not be started until the container has
been prepared for hot work. Workers shall be fully
familiar with AWS F4.1, Safe Practices for the
Preparation of Containers and Piping for Welding and
Cutting, prior to the commencement of hot work.
E6.4 All containers should be considered unsafe for
welding or cutting unless they have been rendered safe,
or declared safe by a qualified person. When welding or
cutting containers, there is the possibility of explosions,
fires, and the release of toxic vapors or fumes. Containers
include jacketed vessels, tanks, drums, covered parts or
other equivalent situations. Seemingly empty containers
might have materials hidden in cracks and crevices,
which will release hazardous fumes when heated by
welding or cutting. By-products of corrosion can result in
explosive atmospheres (hydrogen) in a container. Even a
water tank should be considered hazardous unless a
qualified person has declared it safe to weld or cut.
Information on preparing containers that have held hazardous substances can also be found in NFPA 326,
Standard for the Safeguarding of Tanks and Containers
for Entry, Cleaning, or Repair, and several API documents. See Annexes B and C for details.
16
ANSI Z49.1:2012
7. Confined Spaces
E7.1 Work in confined spaces requires special precautions.
Workers, including both owner and contractor personnel,
should be familiar with written confined space work
program guidelines or should have the work supervised by
a trained person. Asphyxiation causes unconsciousness
and death without warning. Oxygen enriched atmospheres
greatly intensify combustion, and may rapidly cause severe
and often fatal burns.
7.1 Ventilation in Confined Spaces. Ventilation in
confined spaces shall be sufficient to assure adequate
oxygen for life support, to prevent accumulation of
asphixiants or flammable or explosive mixtures, to
prevent oxygen-enriched atmospheres, and to keep
airborne contaminants in breathing atmospheres below
allowable limits, as referred to in 5.1.
7.1.1 Ventilation Before Entry. Confined spaces shall
not be entered unless they are well ventilated and tested to
assure they are safe for entry. When it is not practical to
maintain the space safe for entry, the space shall only be
entered when the following conditions are met:
(1) the space has been tested and determined not to
present an oxygen deficient or oxygen enriched atmosphere, a hazard of fire or explosion, or an atmosphere
hazardous to life;
(2) a trained second person equipped for rescue is
present outside the confined space.
E7.1.1 See 7.5.
7.1.2 Testing Atmospheres. Confined spaces shall
be tested for toxic or flammable gases, dusts, and vapors,
and for adequate or excess oxygen before entering and
during occupancy. The same precautions shall apply to
areas such as pits, tank bottoms, low areas, and areas near
floors when heavier than air gases and vapors are present,
and to areas such as tank tops, high areas and near
ceilings when lighter than air gases are present.
E7.1.2 See ANSI Z117.1 and OSHA 29 CFR 1910.146
for further precautions. If possible, a continuous
monitoring system with audible alarms should be used for
confined space work. Gases such as argon, propane and
carbon dioxide are heavier than air. Gases such as helium
and natural gas are lighter than air.
7.1.3 Adjacent Persons. Adequate ventilation in
confined spaces shall be assured not only to protect
welders or cutters themselves, but to protect all personnel
who may be present in the area.
E7.1.4 Additional information on air quality for
respirators and their use can be found in 29 CFR 1910.134.
7.1.4 Air Quality and Quantity. The quality and
quantity of air for ventilation shall be such that personnel
exposures to hazardous contaminants are maintained
below the allowable limits specified in 5.1. Breathing air
supplied by cylinders or compressors shall meet the
Grade D requirements of ANSI/CGA G-7.1.
The supply air line for respirators shall be a dedicated line
that is not capable of being valved to any other line which
could allow hazardous or toxic gases into the respirator
air line.
7.1.5 Prohibited Ventilation Gases. Oxygen, or any
other gas or mixtures of gases, except air, shall not be
used for ventilation.
E7.1.5 Air may be natural air or synthesized air for
breathing purposes.
7.1.6 Ventilation in Areas Immediately Dangerous
to Life or Health (IDLH). When welding, cutting, or
related processes are performed in areas immediately
dangerous to life or health, the requirements of OSHA 29
CFR 1910.146 shall be followed.
E7.1.6 See 7.5.1 for information on attendant
responsibilities.
17
ANSI Z49.1:2012
7.2 Location of Service Equipment
E7.2 The purpose of this provision is to prevent
contamination of the atmosphere of a confined space by
possible leaks from gas cylinders or fumes from welding
power sources or similar equipment and to minimize the
possibility of electric shock.
7.2.1 Compressed Gas Cylinders and Welding
Power Sources. When welding or cutting in confined
spaces, gas cylinders and welding power sources shall be
located outside the confined space.
7.2.2 Heavy Portable Equipment on Wheels.
Heavy portable equipment mounted on wheels shall be
secured in position to prevent accidental movement
before operations are started in a confined space. See
3.1.3 for additional information.
7.2.3 Ventilation Ducts. Ducts used to provide local
exhaust ventilation for welding, cutting, or related
operations shall be constructed of noncombustible
materials. These ducts shall be inspected as necessary to
insure proper function and that the internal surfaces are
free of combustible residuals.
E7.2.3 When welding or cutting activities occur near
ventilation ducts, or conveyor systems, care should be
taken to see that sparks and spatter are not carried to
locations with combustible or explosive material.
7.3 Adjacent Areas. When welding or cutting is to be
done over, or adjacent to, any confined space, personnel
shall be made aware of the hazards in the confined space
and shall not enter such spaces without first following the
precautions specified in ANSI Z117.1 and OSHA 29 CFR
1910.146.
7.4 Emergency Signal. When a person enters a confined
space through a manhole or other small opening, means
shall be provided for signaling outside personnel for help
as specified in OSHA 29 CFR 1910.146.
7.5 Attendants in Areas Immediately Dangerous to
Life or Health (IDLH). When operations are carried on
in confined spaces where atmospheres immediately
dangerous to life or health may be present or may
develop, attendants shall be stationed on the outside of
the confined space as specified in OSHA 29 CFR
1910.146.
E7.5.1 Rescue operations should take into
consideration such elements as the number of workers
requiring rescue, the time available to perform the rescue
given different accident scenarios, and the time needed
for additional rescue personnel to be summoned.
7.5.1 Attendants Responsibilities. Attendants shall
have a preplanned rescue procedure for quickly removing
or protecting those working inside in case of emergency,
shall observe the workers inside or be in constant
communication with them, and shall be capable of putting
rescue operations into effect. Positive pressure, selfcontained breathing apparatus shall be available for each
attendant required to enter as a rescuer or first responder.
7.5.2 Body Harness Systems. When body harness
systems are used for emergency rescue purposes, they
shall be attached to the person’s body so that they do not
become obstructed in passing through a small or tortuous
exit path in following the preplanned rescue procedure.
18
ANSI Z49.1:2012
7.6 Brazing Furnaces
E7.6 Brazing furnaces are in many respects a type of
confined space. These employ a variety of atmospheres
to exclude oxygen during the brazing process. Such
atmospheres may include inert gas, flammable gas,
flammable gas combustion products, or vacuum. The
following are potential hazards in the operation of
brazing furnaces:
(1) asphyxiation of personnel entering or working in
adjacent areas where there is insufficient oxygen in the
atmosphere to support life;
(2) development of explosive mixtures of flammable
gas and air within the furnace during generation or venting of atmosphere within the furnace;
(3) accumulation of hazardous fumes or gases in the
work area due to the brazing process.
7.6.1 Life Support. If brazing furnaces require
personnel entry into the furnace or adjacent areas, the
provisions of 7.1 shall be observed.
7.6.2 Fire and Explosion. If brazing furnaces utilize
a flammable gas for their interior atmosphere, or if a
flammable gas is burned to create an interior atmosphere,
procedures shall be followed which will assure that an
explosive mixture of flammable gas and air is not
produced in the furnaces.
7.6.3 Venting. Venting of the atmosphere from
within brazing furnaces shall be exhausted to a location
where it will not expose personnel to hazard.
8. Public Exhibitions and
Demonstrations
E8. Refer to NFPA 51B. Local codes
and regulations may require
additional measures.
8.1 Application. All requirements of the standard shall
apply to public exhibitions and demonstrations, except
when superseded by this section.
E8.1 This section contains safety precautions specific to
welding and cutting performed at public demonstrations
and exhibits, displays, and trade shows (referred to
hereinafter as the site) to ensure the protection of viewers,
demonstrators, and the public.
8.2 Supervision. Installation and operation of welding,
cutting, and related equipment shall be done by, or under
the supervision of, a qualified person.
8.3 Site
8.3.1 Site Design. The site shall be constructed,
equipped, and operated so as to minimize the possibility
of injury to viewers at the site.
8.3.2 Site Location. Materials and equipment on the
site shall be located so as not to interfere with evacuation
of people during an emergency.
19
ANSI Z49.1:2012
8.4 Fire Protection
E8.4 See also clause 6, Fire Prevention and Protection.
8.4.1 Extinguishers. Sites shall be provided with
portable fire extinguishers of appropriate size and type.
8.4.2 Combustibles. Combustible materials at the
site shall be shielded from flames, sparks, and molten
metal.
8.4.3 Fire Department. The fire department shall be
notified in advance of such use of the site.
E8.5 See also clause 6, Fire Prevention and Protection.
8.5 Protection of the Public
8.5.1 Flames, Flying Sparks, and Molten Metal.
The public shall be shielded from flames, flying sparks,
and molten metal.
8.5.2 Radiation. The public shall be shielded from
harmful ultraviolet, infrared, and other electromagnetic
radiation. Shielding shall protect direct viewers and
adjacent passersby.
8.5.3 Fumes and Gases. The public shall be
protected from inhalation of hazardous concentrations of
fumes and gases.
8.5.4 Electrical Shock. The public shall be protected
from contact with live electrical parts.
E8.6 See also 10.8 and 10.9.
8.6 Cylinders
8.6.1 Capacity. Cylinders shall not be charged in
excess of one-half their maximum permissible capacity
by weight or pressure. Cylinders of non liquefied gases
and acetylene shall be charged to not more than one-half
their maximum permissible charged pressure in psig
(kPa). Cylinders of liquefied gases shall be charged to not
more than one-half the maximum capacity in pounds
(kilograms).
8.6.2 Storage. Unconnected cylinders, stored at the
site, shall be limited to approximately one day’s
consumption of each gas used. Other cylinders shall be
stored in an approved storage area, preferably outdoors
but not near a building exit.
8.6.3 Trucks. When transported, cylinders weighing
more than 40 pounds (18 kilograms), shall be carried on a
hand or motorized truck.
E8.6.4 Cylinder valves should be closed and capped
when equipment is unattended for an extended time, such
as for several days. See 8.6.5.
8.6.4 Cylinder Valves. Cylinder valves shall be
closed when equipment is unattended.
8.6.5 Valve Caps. Where cylinders are designed to be
equipped with valve protection caps, the caps shall be in
place except when the cylinders are in service or
connected ready for service.
8.6.6 Protection. Cylinders shall be located or
secured so that they cannot be knocked over.
20
ANSI Z49.1:2012
8.7 Process Hoses, Cables, and Conduits
E8.7 See also 10.6.
8.7.1 Physical Damage. Hoses, cables, and conduits
shall be located and protected so that they will not be
physically damaged.
8.7.2 Tripping. Hoses, cables, and conduits shall be
located and protected to minimize tripping hazard.
9. Precautionary Information
9.1 General. Personnel shall be informed of the
potential hazards from fumes, gases, electric shock, heat,
radiation, and noise.
E9.1 Refer to clause 4, Protection of Personnel and the
General Area, for additional information on potential
hazards. See also OSHA 29 CFR Section 1910.1200.
9.2 Precautionary Information for Arc Welding and
Related Processes and Equipment. The information
shown in Figure 1, or its equivalent, shall be placed on
stock containers of materials such as wires, fluxes, and
electrodes and on major equipment such as power
supplies, wire feeders, and controls used in arc welding,
arc cutting, and allied processes. The information shall be
readily visible and may be on a label, tag, or other printed
form.
E9.2 This information is a minimum requirement.
Additional information and labeling may be required by
other standards and regulations. The message is the
important thing. This information is intended to get it to
the final user. See also the ANSI Z535 series of standards
on safety signs and colors.
First aid information is generally recommended only on
products that present immediate and major health hazards.
A label identification number should appear on the label.
Where noise has been determined to be a hazard, the
statement of hazard, “NOISE can damage hearing,” shall
be placed after the statement of hazard, “ELECTRIC
SHOCK can KILL.”
When materials are determined to be more hazardous than
those requiring the use of WARNING as a signal word,
the signal word should be changed to DANGER and an
appropriate precautionary message should be added.
When provided, first aid information shall follow the last
precautionary measure.
The company name and address shall appear on the label
unless it is readily visible elsewhere on the product.
E9.3 See comment for 9.2. Some processes are arcless
and flameless. Modify the information in Figure 2 to
reflect the proper heat source and appropriate hazards.
9.3 Precautionary Information for Oxyfuel Gas
Processes and Equipment. As a minimum, the
information shown in Figure 2, or its equivalent, shall be
placed on stock containers of materials such as rods and
fluxes, and on major equipment used in oxyfuel gas
welding, cutting, and allied processes. The information
shall be readily visible and may be on a label, tag, or other
printed form.
Where noise has been determined to be a hazard, the
statement of hazard, “NOISE can damage hearing” shall
be placed after the statement of hazard, “HEAT RAYS
(INFRARED RADIATION) from flame or hot metal can
injure eyes.” This information shall follow the last precautionary measure. The company name and address
shall appear on the label unless it is readily visible elsewhere on the product.
9.4 Hazardous Materials Information. When the fume
from a product contains a by-product component whose
allowable limit will be exceeded before the general
welding fume allowable limit, the by-product component
E9.4 A number of potentially hazardous materials are
employed in the fluxes, coatings, coverings, and filler
metals used in welding and cutting, or are released to the
atmosphere during welding and cutting. Material Safety
21
ANSI Z49.1:2012
WARNING:
WARNING:
PROTECT yourself and others. Read and understand this
information
PROTECT yourself and others. Read and understand this
information.
FUMES AND GASES can be hazardous to your health.
FUMES AND GASES can be hazardous to your health.
ARC RAYS can injure eyes and burn skin.
ELECTRIC SHOCK can KILL.
HEAT RAYS (INFRARED RADIATION) from flame or
hot metal can injure eyes.
• Before use, read and understand the manufacturer’s
instructions, Material Safety Data Sheets (MSDSs),
and your employer’s safety practices.
• Before use, read and understand the manufacturer’s
instructions, Material Safety Data Sheets (MSDSs),
and your employer’s safety practices.
• Keep your head out of the fumes.
• Keep your head out of the fumes.
• Use enough ventilation, exhaust at the arc, or both, to
keep fumes and gases from your breathing zone and
the general area.
• Use enough ventilation, exhaust at the flame, or both,
to keep fumes and gases from your breathing zone and
the general area.
• Wear correct eye, ear, and body protection.
• Wear correct eye, ear, and body protection.
• Do not touch live electrical parts.
• See American National Standard Z49.1, Safety in
Welding, Cutting, and Allied Processes, published by
the American Welding Society, 550 NW LeJeune
Road, Miami, FL 33126; OSHA Safety and Health
Standards, available from the U.S. Government
Printing Office.
• See American National Standard Z49.1, Safety in
Welding, Cutting, and Allied Processes, published by
the American Welding Society, 550 NW LeJeune
Road, Miami, FL 33126; OSHA Safety and Health
Standards, available from the U.S. Government
Printing Office.
DO NOT REMOVE THIS INFORMATION
DO NOT REMOVE THIS INFORMATION
Figure 1—Precautionary Information for
Arc Welding Processes and Equipment
Figure 2—Precautionary Information for
Oxyfuel Gas Processes and Equipment
shall be identified on the Material Safety Data Sheet
(MSDS). These include, but shall not be limited to, byproducts of the materials itemized in 5.5.1.
Data Sheets (MSDSs) are required by federal regulations.
See also 9.7.
9.5 Brazing Filler Metals Containing Cadmium. As a
minimum, brazing filler metals containing cadmium as a
designated constituent shall carry the information shown
in Figure 3, or its equivalent, on tags, boxes, or other
containers, and on any coils of wire not supplied to the
user in a labeled container.
E9.5 See E9.3.
9.6 Brazing and Gas Welding Fluxes Containing
Fluorides. As a minimum, brazing and gas welding
fluxes containing fluorine compounds shall have
precautionary information as shown in Figure 4, or its
equivalent, on tags, boxes, or other containers to indicate
that they contain fluorine compounds.
E9.6 See E9.3.
9.7 Material Safety Data Sheets (MSDSs). The
suppliers of welding materials shall provide a Material
Safety Data Sheet which identifies the hazardous materials,
if any, used in their welding and cutting products.
E9.7 MSDSs are required by OSHA 29 CFR Section
1910.1200.
22
ANSI Z49.1:2012
DANGER: Contains cadmium.
WARNING: Contains fluorides.
Protect yourself and others. Read and understand this
information.
Protect yourself and others. Read and understand this
information.
FUMES ARE POISONOUS AND CAN KILL.
FUMES AND GASES CAN BE HAZARDOUS TO
YOUR HEALTH. BURNS EYES AND SKIN ON CONTACT. CAN BE FATAL IF SWALLOWED.
• Before use, read and understand the manufacturer’s
instructions, Material Safety Data Sheets (MSDSs),
and your employer’s safety practices.
• Before use, read and understand the manufacturer’s
instructions, Material Safety Data Sheets (MSDSs),
and your employer’s safety practices.
• Do not breathe fumes. Even brief exposure to high
concentrations should be avoided.
• Keep your head out of the fume.
• Use enough ventilation or exhaust, or both, to keep
fumes and gases from your breathing zone and the
general area.
• Use enough ventilation or exhaust, or both, to keep
fumes and gases from your breathing zone and the
general area. If this cannot be done, use air supplied
respirators.
• Avoid contact of flux with eyes and skin.
• Do not take internally.
• Keep children away when using.
• Keep children away when using.
• See American National Standard Z49.1, Safety in
Welding, Cutting, and Allied Processes, published by
the American Welding Society, 550 NW LeJeune
Road, Miami, FL 33126; OSHA Safety and Health
Standards, available from the U.S. Government
Printing Office.
• See American National Standard Z49.1, Safety in
Welding, Cutting, and Allied Processes, published by
the American Welding Society, 550 NW LeJeune
Road, Miami, FL 33126; OSHA Safety and Health
Standards, available from the U.S. Government
Printing Office.
First Aid: If contact in eyes, flush immediately with water
for at least 15 minutes. If swallowed, induce vomiting.
Never give anything by mouth to an unconscious person.
Call a physician.
First Aid: If chest pain, shortness of breath, cough, or fever
develops after use, obtain medical help immediately.
DO NOT REMOVE THIS INFORMATION
DO NOT REMOVE THIS INFORMATION
Figure 3—Precautionary Information for
Brazing Filler Metals Containing Cadmium
Figure 4—Precautionary Information for
Brazing and Gas Welding Fluxes
Containing Fluorides
9.8 Graphic Symbols. Graphic symbols shall be
permitted in place of text when they present equivalent
precautionary information.
E9.8 See also ANSI Z535 and NEMA EW6, Guidelines
for Precautionary Labeling for Arc Welding and Cutting
Products.
9.9 Hazard Communications. Employers shall assure
that the information described in this section is
communicated to end users of the products (see 3.2.1.2 of
this standard).
23
ANSI Z49.1:2012
Part II
Specific Processes
10. Oxyfuel Gas Welding and Cutting
Safety
10.1 Scope. This section covers safe practices for users
of oxyfuel gas welding, cutting, soldering, brazing, and
related materials and equipment. It does not cover
specifications for the design and construction of such
equipment, nor for the construction or installation of bulk
gas supply or piping distribution systems.
E10.1 Note that this applies to
manufacturers of equipment. See 1.3.
USERS,
not
10.2 Terminology
10.2.1 Call Oxygen by Name. Oxygen shall be called
by its proper name, oxygen, and not by the word “air.”
E10.2.1 Use of this proper name will decrease the
probability of misuse.
10.2.2 Call Fuel Gases by Name. Fuels, fuel gases,
and liquid fuels shall be called by their proper names,
such as, acetylene, propane, natural gas, and not by the
word “gas.”
E10.2.2 Proper identity is needed to determine the
correct hazards.
10.3 Oxygen and Combustibles
10.3.1 Keep Oxygen from Combustibles. Oxygen
cylinders, cylinder valves, couplings, regulators, hoses,
and apparatus shall be kept free from oil, grease, and
other flammable or explosive substances. Oxygen
cylinders or apparatus shall not be handled with oily
hands or gloves.
E10.3.1 Oxygen will not burn, but vigorously supports
and accelerates combustion, causing materials to burn
with great intensity. Oil or grease in the presence of
oxygen may ignite readily and burn violently.
10.3.2 Prohibited Uses for Oxygen. Oxygen shall
not be used as a substitute for compressed air. Oxygen
shall not be used in pneumatic tools, in oil preheating
burners, to start internal combustion engines, to blow out
pipelines, to dust clothing or work, or to create pressure
for ventilation or similar applications. Jets of oxygen
shall not be permitted to strike an oily surface, greasy
clothing, or enter fuel oil or other storage tanks.
E10.3.2 These prohibitions decrease the possibility of
a raging oxygen-fed fire occurring. Oxygen is not
flammable, but vigorously supports combustion. Oxygen
can be adsorbed by clothing. A slight spark can result in
severe burns.
10.3.3 Oxygen Equipment. Oxygen cylinders,
equipment, pipelines, or apparatus shall not be used
interchangeably with any other gas.
E10.3.3 Contamination of oxygen equipment with
combustible substances may lead to spontaneous
combustion or explosion in oxygen.
10.4 Attachments for Gas Mixing. No device or
attachment facilitating or permitting mixtures of air or
oxygen with flammable gases prior to consumption,
except at a burner or in a torch, shall be allowed unless
approved for the purpose.
E10.4 This prevents the accumulation of explosive
mixtures.
10.5 Torches
E10.5.1 For additional information on torches, see
CGA E-5, Torch Standard for Welding and Cutting.
10.5.1 Approval. Only approved torches, as defined
in 2.1, shall be used.
24
ANSI Z49.1:2012
10.5.2 Operation
10.5.2.1 Leak Testing Connections. Connections
shall be checked for leaks after assembly and before
lighting the torch. Flames shall not be used.
E10.5.2.1 Leak test solutions for use on oxygen
connections are commercially available and are
recommended. Leak testing should be repeated after the
equipment has been used in a manner that could cause
leaks.
10.5.2.2 Purging Hoses. Before lighting the torch
for the first time each day, hoses shall be purged
individually. Hoses shall not be purged into confined
spaces or near ignition sources. Hoses shall be purged
after a cylinder change.
E10.5.2.2 Purging consists of allowing each gas to
flow through its respective hose separately, to purge out
any flammable mixture in the hose. It is important to
purge before lighting the torch.
10.5.2.3 Lighting Torch. A friction lighter,
stationary pilot flame, or other suitable source of ignition
shall be used. Matches, cigarette lighters, or welding arcs,
shall not be used for lighting torches.
E10.5.2.3 This is to minimize burns of hands and
fingers. Do not attempt to light or relight torch from hot
metal in a small cavity, hole, furnace, etc., where gas
might accumulate. Point the torch away from persons or
combustible materials.
Manufacturers’ procedures shall be followed with respect
to the sequence of operations in lighting, adjusting, and
extinguishing torch flames.
10.5.2.4 Confined Space. In confined spaces, the
torch valves shall be closed and in addition, the fuel gas
and oxygen supply to the torch shall be positively shut off
at a point outside the confined area whenever the torch is
not to be used, such as during lunch or overnight.
Unattended torches and hoses shall be removed from the
confined space.
E10.5.2.4 This is to minimize the possibility of gas
accumulation in confined space due to leaks or
improperly closed valves when gas welding or cutting is
completed. See also clause 7, Confined Spaces, of this
standard, for other precautions to be observed in working
in confined spaces.
10.6 Hose and Hose Connections
10.6.1 Specification. Hose for oxyfuel gas service
shall comply with the Rubber Manufacturers Association
IP-7 Specification for Rubber Welding Hose.
E10.6.1 Metal-Clad or armored hose is not
recommended. However, as part of a machine or an
appliance when conditions of use make metal reinforcing
advantageous, hose may be used in which such metal
reinforcing is exposed to neither the inside gases nor the
outdoor atmosphere.
10.6.2 Colors. Hoses for oxyfuel gas service shall be
color coded according to the authorities having
jurisdiction.
E10.6.2 The generally recognized colors in the United
States are red for fuel gas hose, green for oxygen hose,
and black for inert-gas and air hose. Other countries
sometimes use different colors. International colors
generally recognized are described in ISO 3821,
Welding—Rubber Hoses for Welding, Cutting, and Allied
Processes.
10.6.3 Taping. When parallel lengths of oxygen and
fuel gas hose are taped together for convenience and
to prevent tangling, not more than 4 inches (100
millimeters) in each 12 inches (300 millimeters) shall be
covered by tape.
E10.6.3 This leaves 2/3 of the hoses visible for color
identification, and provides adequate ventilation to
prevent gas entrapment in the event of hose leaks.
10.6.4 Maintenance. Hose showing leaks, burns,
worn places, or other defects rendering it unfit for service
shall be repaired or replaced.
E10.6.4 Frequency of inspection depends upon the
amount and severity of use. Bending areas at the
regulator and torch connections are prone to crack and
leak because of additional stress.
25
ANSI Z49.1:2012
10.6.5 Hose Connection Specifications. Hose
connections shall comply with the standard hose
connection specification, CGA Pamphlet E-1, Regulator
Connection Standards.
Hose connections for welding gas lines shall not be compatible with connections for breathing air.
10.6.6 Hose Connection Quality. Hose connections
shall be fabricated in a manner that will withstand,
without leakage, twice the pressure to which they are
normally subjected in service, but in no case less than
300 psi (2070 kPa). Oil-free air or an oil-free inert gas
shall be used for testing.
10.6.7 Devices. Only approved devices as defined in
2.1 shall be used in oxyfuel gas systems.
E10.6.7 When an approved device such as a hose
check valve or flash-back arrestor is used in an oxyfuel
gas welding and cutting torch system, the device should
be used and maintained in accordance with the
manufacturers’ instructions. Refer to CGA Pamphlet E-2,
Standard Hose Connection Specifications.
10.6.7.1 The use of suitable approved flashback
arrestors shall be permitted.
E10.6.7.1 Flashback arrestors can provide a certain
measure of protection against the hazards of flashback.
To maintain this protection and to ensure that they have
not become damaged or inoperative during use, a routine
inspection program should be followed as specified
during use. Also, a regular inspection program should be
followed as specified in the instructions provided by the
manufacturer.
Many years of field experience has shown various oxyfuel gas torches to be reliable and safe apparatus when
operated in accordance with instructions recommended
by the manufacturer. Under certain circumstances, the
user’s failure to follow these instructions can cause the
backflow (reverse flow) of unwanted gas and/or flashback
into the upstream equipment.
10.7 Pressure-Reducing Regulators
10.7.1 Approval. Only approved pressure reducing
regulators, as defined in 2.1, shall be used.
E10.7.1 Refer to CGA E-4, Standard for Gas
Regulators for Welding and Cutting.
10.7.2 Designated Service. Pressure reducing
regulators shall be used only for the gas and pressures for
which they are labeled. The regulator inlet connections
shall comply with ANSI/CGA Standard V-1, Standard
for Compressed Gas Cylinder Valve Outlet and Inlet
Connections.
E10.7.2 Contamination can lead to explosions and fire.
Regulators shall not be interchanged among designated
gas services.
10.7.3 Inspection Before Use. Union nuts and
connections on regulators shall be inspected before use to
detect faulty seats which may cause leakage when the
regulators are attached to cylinder valves or hoses.
Damaged nuts or connections shall be replaced.
26
ANSI Z49.1:2012
10.7.4 Oxygen Gauges. Gauges used for Oxygen
service shall be marked “USE NO OIL.”
10.7.5 Oxygen Regulators. Regulators shall be
drained of oxygen before they are attached to a cylinder
or manifold, or before the cylinder valve is opened (see
also 10.8.4.4 and 10.8.4.11). Oxygen cylinder or
manifold valves shall always be opened slowly (see
10.8.4.3 and 10.8.4.4).
E10.7.5 The regulator attached to a cylinder can be
drained of oxygen by momentarily opening and then
closing the downstream line to the atmosphere with the
regulator adjusting screw engaged and the cylinder valve
closed. The cylinder valve is then opened slowly. The
oxygen cylinder or manifold outlet connection should be
wiped clean with a clean cloth, free of oil and lint, and the
cylinder valve “cracked” before connecting the regulator.
(See 10.8.4.3.)
These steps help reduce the chance of oxygen fed regulator fires when the regulator is pressurized from a highpressure source.
10.7.6 Maintenance. When regulators or parts of
regulators, including gauges, need repair, the work shall
be performed by qualified mechanics.
10.8 Compressed
(Containers)
and
Oxyfuel
Gas
Cylinders
E10.8 Compressed gas cylinders used in welding and
cutting processes contain gases generally at pressures
approximately 2500 psi (17237 kPa), but sometimes
much higher. Gases at these pressures are dangerous if
not properly handled. The procedures described in this
section are intended to prevent damage or abuse to gas
cylinders which might cause them to leak or explode with
the consequence of serious damage, injury, or death.
10.8.1 General Cylinder Provisions
10.8.1.1 Approval. All portable cylinders used for
storage and shipment of compressed gases shall be
constructed and maintained in accordance with 49 CFR
173 regulations of the U.S. Department of Transportation
(DOT).
10.8.1.2 Filling Authorization. No one except the
owner of the cylinder or person authorized by the owner
shall fill a cylinder.
10.8.1.3 Mixing Gases. No person other than the
gas supplier shall mix gases in a cylinder or transfill gases
from one cylinder to another.
10.8.1.4 Content Identification. Compressed gas
cylinders shall be legibly marked with either the chemical
or the trade name of the gas in conformance with
ANSI/CGA C-7, Guide to Preparation of Precautionary
Labeling and Marking of Compressed Gas Containers,
for the purpose of identifying the gas content. Cylinders
on which the labeling is missing or illegible shall not be
used. They shall be returned to the supplier.
10.8.1.5 Changing Markings. The numbers and
markings stamped into cylinders shall not be changed
except in conformance with 49 CFR 173 U.S. DOT
regulations.
27
ANSI Z49.1:2012
10.8.1.6 Connection Threads. Compressed gas
cylinders shall be equipped with connections complying
with ANSI/CGA V-1, Standard for Compressed Gas
Cylinder Valve Outlet and Inlet Connections.
10.8.1.7 Valve Protection. All cylinders with a
water weight capacity over 30 pounds (13.6 kilograms)
shall be equipped with a means of connecting a valve
protection cap or with a collar or recess to protect the
valve.
E10.8.1.8 Hot gases may expand and increase
pressures above allowable limits. For additional
information, contact the Compressed Gas Association.
10.8.1.8 Cylinder Temperature. The storage
temperature of the cylinder contents shall not be allowed
to exceed 125°F (52 °C). The use temperature shall not
exceed 120°F (49 °C).
10.8.1.9 Damaged Cylinders. Cylinders evidencing
severe damage, corrosion, or fire exposure shall not be used.
10.8.2 Cylinder Storage
E10.8.2.1 Check for overhead combustibles such
as overhead lines and piping, suspended ceiling
materials, etc., when considering storage location. The
storage location should be well ventilated so as to avoid
the accumulation of hazardous gases in the event of
cylinder leakage.
10.8.2.1 Protection. Cylinders shall be stored
where they will not be exposed to physical damage,
tampering, or subject to temperatures which would raise
the contents above the limits of 10.8.1.8.
Cylinders shall be stored away from elevators, stairs, or
gangways in assigned places where cylinders will not be
knocked over or damaged by passing or falling objects.
Cylinders shall be secured in storage to prevent falling.
E10.8.2.2 Heat can cause pressure to rise and may
lead to cylinder rupture or operation of protective devices.
10.8.2.2 Cylinders Separated from Combustibles.
Cylinders in storage shall be separated from flammable and
combustible liquids and from easily ignited materials such
as wood, paper, packaging materials, oil, and grease by at
least 20 feet (6.1 meters), or by a noncombustible barrier
at least 5 feet (1.6 meters) high having a fire resistance of at
least one-half hour.
10.8.2.3 Oxygen Separated from Fuel Gas.
Oxygen cylinders in storage shall additionally be
separated from fuel gas cylinders, or from reserve stocks
of calcium carbide, by a distance or barrier as described
in 10.8.2.2.
10.8.2.4 Oxygen in Acetylene Generator
Buildings. Oxygen cylinders stored in outside acetylene
generator houses shall be separated from the generator or
carbide storage rooms by a noncombustible partition
having a fire resistance of at least one hour. This partition
shall be without openings and shall be gas-tight.
Oxygen shall not be stored inside acetylene generator
rooms.
10.8.2.5 Fuel Gas Cylinders Upright. Acetylene
and liquefied gas cylinders shall be used valve end up.
E10.8.2.5 This prevents liquid flow into hoses and
regulators.
10.8.2.6 Fuel Gas Storage Limits. Fuel gas
storage limits shall be in accordance with NFPA 51,
28
ANSI Z49.1:2012
Standard for the Design and Installation of Oxygen-Fuel
Gas Systems for Welding, Cutting, and Allied Processes.
10.8.3 Cylinder Handling
10.8.3.1 Rough Handling. Cylinders shall not be
dropped, struck, or permitted to strike objects violently in
a manner which may damage the cylinder, valve, or safety
device.
10.8.3.2 Pry Bars. Bars shall not be used under
valves or valve protection caps to pry cylinders loose
when frozen to the ground or otherwise fixed.
E10.8.3.2 The use of warm (not boiling) water is
recommended.
10.8.3.3 Rollers or Supports. Cylinders shall
never be used as rollers or supports, whether full or empty.
10.8.3.4 Safety Devices. Safety devices shall not
be tampered with.
10.8.3.5 Closed Valves. Cylinder valves shall be
closed before moving cylinders.
E10.8.3.6 Cylinder valve protection caps should be
kept with the cylinders so they can be reassembled when
the regulator is removed.
10.8.3.6 Valve Protection Caps. Valve protection
caps, where the cylinder is designed to accept a cap, shall
always be in place and handtight (except when cylinders
are in use or connected for use).
10.8.3.7 Manual Lifting. Valve protection caps
shall not be used for lifting cylinders.
10.8.3.8 Lifting Equipment. When transporting
cylinders by a crane or derrick, a cradle or suitable
platform shall be used. Slings or electromagnets shall not
be used for this purpose.
E10.8.3.9 It is especially hazardous to transport
cylinders of fuel gas inside any vehicle, such as an
automobile, where gas from a leak can accumulate inside
the passenger compartment or trunk. Opening the door or
trunk will activate a light switch that acts to ignite the
accumulated gas and cause a deadly explosion.
10.8.3.9 Transporting Cylinders. When cylinders
are transported by motor vehicle, they shall be secured
and transported in accordance with Department of
Transportation regulations, when required.
10.8.3.10 Cylinders with Regulators Attached.
When cylinders are to be moved with regulators attached,
the cylinders shall be secured in position when moved,
and cylinder valve closed.
10.8.4 Cylinder Use
10.8.4.1 Pressure Regulator. Compressed gas
shall never be used from cylinders without reducing the
pressure through a suitable regulator attached to the
cylinder valve or manifold, unless the equipment used is
designed to withstand full cylinder pressure.
10.8.4.2 Maximum
Acetylene
Pressure.
Acetylene shall not be utilized at a pressure in excess of
15 psig (103 kPa) or 30 psia (206 kPa). This requirement
shall not apply to storage of acetylene dissolved in a
suitable solvent in cylinders manufactured and
maintained according to Department of Transportation
requirements, or to acetylene for chemical use.
E10.8.4.2 Acetylene can dissociate (decompose
with explosive violence) above these pressure limits.
The 30 psia (206 kPa) limit is intended to prevent unsafe
use of acetylene in pressurized chambers such as caissons, underground excavations, or tunnel construction.
29
ANSI Z49.1:2012
10.8.4.3 “Cracking” Cylinder Valve. Before
connecting a regulator to a cylinder valve, the valve
outlet shall be wiped clean with a clean cloth free of oil
and lint, and the valve shall be opened momentarily and
closed immediately.
E10.8.4.3 This action, generally termed cracking,
is intended to clear the valve of dust or dirt that otherwise
might enter the regulator.
The valve shall be cracked while standing to one side of
the outlet, never in front of it. Fuel gas cylinder valves
shall not be cracked near other welding work or near
sparks, flame, or other possible sources of ignition.
10.8.4.4 Special
Procedure
for
Oxygen
Cylinders. The following shall be done after the
regulator is attached to oxygen cylinders:
(1) Engage the adjusting screw and open the downstream line to drain the regulator of gas.
(2) Disengage the adjusting screw and open the cylinder valve slightly so that the regulator cylinder-pressure
gauge pointer moves up slowly before opening the valve
all the way.
(3) Stand to one side of the regulator and not in front
of the gauge faces when opening the cylinder valve.
E10.8.4.4 If oxygen at high pressure is suddenly
applied, it is possible to cause ignition of regulator
components and injure the operator. See CGA Pamphlet
E-4 for additional information.
10.8.4.5 Hammer or Wrench. A hammer or
wrench shall not be used to open cylinder valves that are
fitted with hand wheels.
10.8.4.6 Special Wrench. Cylinders not having
fixed hand wheels shall have keys, handles, or
nonadjustable wrenches on valve stems while these
cylinders are in service so that the gas flow can be turned
off quickly in case of emergency. In multiple cylinder
installations, at least one such wrench shall always be
available for immediate use.
10.8.4.7 Valve Wide Open. When a high-pressure
(nonliquefied) gas cylinder is in use, the valve shall be
opened fully in order to prevent leakage around the valve
stem.
E10.8.4.8 This is so that it may be closed quickly in
case of emergency.
10.8.4.8 Valve Partially Open. An acetylene
cylinder valve shall not be opened more than approximately
one and one-half turns and preferably no more than threefourths of a turn, unless otherwise specified by the
manufacturer.
10.8.4.9 Interference. Nothing shall be placed on
top of a cylinder when in use which may damage the
safety device or interfere with the quick closing of the
valve.
10.8.4.10 Valves Closed. Cylinder valves shall be
closed whenever the equipment is unattended.
10.8.4.11 Draining Regulator. Before a regulator
is removed from a cylinder, the cylinder valve shall be
closed and the gas released from the regulator.
10.8.4.12 Secure Cylinders During Use. A
suitable cylinder truck, chain, or steadying device shall
30
ANSI Z49.1:2012
be used to keep cylinders from being knocked over while
in use.
10.8.4.13 Fire Protection. Cylinders shall be kept
far enough away from actual welding or cutting
operations so that sparks, hot slag, or flame will not reach
them, otherwise fire resistant shields shall be provided.
10.8.4.14 Electric Circuits. Cylinders shall not be
placed where they might become part of an electrical
circuit. Contacts with third rails, trolley wires, etc. shall
be avoided. Cylinders shall be kept away from radiators,
piping systems, layout tables, etc. that may be used for
grounding electric circuits such as for arc welding
machines. The tapping of electrodes against a cylinder
shall be prohibited. Do not strike an arc on cylinders.
E10.8.4.14 Cylinders should not be so grounded, or
located, where they can become part of an electric circuit.
Arc damaged cylinders may leak or explode.
10.8.4.15 Fuel Gas Cylinder Withdrawal Rates.
Withdrawal rates from gas cylinders shall not exceed
manufacturers’ recommendations.
E10.8.4.15 In the case of acetylene, excessive
withdrawal rates can lead to acetone depletion from the
cylinder. Some materials may be damaged by acetone
and create leaks. The stability of acetylene may be
reduced. In the case of liquefied fuel gases, excessive
withdrawal rates will cause refrigeration.
10.8.5 Cylinder Emergencies
10.8.5.1 Fuel Valve Packing Leak. If a leak is
found around the valve stem of a fuel gas cylinder, the
packing nuts shall be tightened, or the cylinder valve closed.
E10.8.5.1 Leaks can lead to oxygen deficient or
explosive atmospheres.
10.8.5.2 Fuel Gas Leaks Which Cannot be
Stopped. If tightening the packing nut does not stop a
valve stem leak, or if a fuel gas valve is leaking at the seal
and cannot be stopped by closing the valve firmly, or if a
leak should develop at a cylinder fuse plug or other safety
device, then the fuel gas cylinders shall be moved to a
safe location outdoors, away from any source of ignition,
marked properly, and the supplier advised.
E10.8.5.2 Outdoors, the cylinder valve may be
opened slightly to gradually discharge the contents.
When a leaking cylinder cannot be moved safely to a
location outdoors, the area or building shall be immediately evacuated and the fire department notified of the
emergency.
A precautionary sign shall be posted not to approach the
leaking cylinder with a lighted cigarette or source of
ignition.
10.8.5.3 Fuel Cylinder Fires. Small fires at fuel
gas cylinders, usually resulting from ignition of leaks
described in 10.8.5.1 and 10.8.5.2, shall be extinguished,
if possible, by closing the cylinder valve or by the use of
water, wet cloths, or fire extinguisher. The leaks shall
then be treated as described in those sections.
E10.8.5.3 It is usually better to allow the fire to
continue to burn and consume the escaping gas,
otherwise it may reignite with explosive violence. If
circumstances permit, it is often better to allow the
cylinder fire to burn out in place rather than attempt to
move the cylinder.
In the case of a large fire at a fuel gas cylinder, such as
from the functioning of a fuse plug or safety device, personnel shall be evacuated from the area, and the cylinder
kept wet with a heavy water stream to keep it cool.
If the cylinder is located where the fire should not be
allowed to burn out in place, attempts may be made to
move it to a safer location, preferably outdoors.
Personnel should remain as distant as possible, and the
cylinder should be kept cool with a water stream.
31
ANSI Z49.1:2012
10.9 Cylinder Manifolding
10.9.1 Approval. Fuel gas manifolds and highpressure oxygen manifolds for use with oxygen cylinders
having a DOT service pressure above 250 psig (1724
kPa) shall be approved either separately for each
component part or as an assembled unit.
10.9.2 Gas Service. All manifolds and parts shall be
used only for the gases for which they are approved.
10.9.3 Fuel Gas Manifold Capacity Limits and
Locations. Fuel gas manifold capacity limits and
locations shall be in accordance with NFPA 51.
E10.9.3 NFPA 51 has established a 3000 cubic foot
(84 cubic meters) total nonliquefied gas capacity as an
indoor limit for fuel gas cylinders connected to one
manifold. The rationale for this limit is that a typical
building of 100 feet by 100 feet with a 15 feet ceiling
(150 000 cubic feet, 4200 cubic meters) could contain a
leak of 3000 cubic feet of acetylene and not exceed the
lower explosive limit if uniformly distributed. Acetylene
has the lowest explosive limit of the commonly used fuel
gases. See NFPA 51 for additional details.
10.9.4 Oxygen Manifold Capacity Limits and
Locations. Oxygen manifold capacity limits and
locations shall be in accordance with NFPA 51.
10.9.5 Manifold Requirements. Fuel gas and
oxygen manifolds requirements shall be in accordance
with NFPA 51.
10.9.6 Manifold Installation and Operation.
Manifold installation and operation shall be in
accordance with NFPA 51.
11. Arc Welding and Cutting
Equipment Safety
11.1 General
11.1.1 Scope. This section contains safety
precautions specific to the installation and operation of
arc welding and cutting equipment.
E11.1.2 Gas equipment used in arc welding should be
handled as described in Clause 10, Oxyfuel Gas Welding
and Cutting Safety. See 11.5.5.
11.1.2 Equipment. Arc welding and cutting
equipment shall be chosen as specified in 11.2 and shall
be installed as specified in 11.3.
11.1.3 Personnel. Persons in charge of the equipment
or designated to operate the arc welding and cutting
equipment shall have been properly instructed and
qualified to maintain or operate such equipment and
approved as competent for their work responsibilities.
Rules and instructions covering the operation and
maintenance of the arc welding and cutting equipment
shall be readily available.
32
ANSI Z49.1:2012
11.2 Safety Aspects in Selection of Arc Welding
Equipment
11.2.1 Safety Standards. Safety in design of arc
welding equipment shall be in compliance with
applicable NEMA and ANSI standards. Special purpose
machines not covered by the above listed standards shall
conform in all aspects to the standards set forth in this
publication.
11.2.2 Environmental Conditions. When using
alternating current (ac) or direct current (dc) arc welding
machines, the welding operator shall take special care to
prevent electrical shock, when working under electrically
hazardous conditions. The manufacturer shall be consulted
when unusual service conditions are encountered.
E11.2.2 Water or perspiration may cause electrically
hazardous conditions. Electrical shock may be prevented
by the use of nonconductive gloves, clothing, and shoes
and avoiding contact with live electrical parts.
Other examples of electrically hazardous conditions are
locations in which the freedom of movement is restricted
so that the operator is forced to perform the work in a
cramped (kneeling, sitting, lying) position with physical
contact with conductive parts, and locations that are fully
or partially limited by conductive elements and in which
there is a high risk of unavoidable or accidental contact
by the operator. These hazards can be minimized by insulating conductive parts near the vicinity of the operator.
If a significant amount of work time is spent in electrically
hazardous conditions, the use of automatic controls is recommended to reduce the no-load voltage to a value not to
exceed 38 volts rms ac or 50 volts direct current (dc) at rated
input voltage. This also applies to 11.2.3.1. Examples of
unusual service conditions are described in ANSI/NEMA
EW1, Electric Arc Welding Power Sources.
11.2.3 Other Conditions
11.2.3.1 Open-Circuit
Voltage
(Special
Processes). When special welding and cutting processes
require open-circuit voltages higher than those specified
in ANSI/NEMA EW1, adequate insulation or other
means shall be provided to protect the operator from
making contact with the high voltage.
E11.2.3.1 Some processes such as plasma arc
cutting may utilize open-circuit voltages as high as
400 volts dc. Precautionary labeling, workplace placards,
or special employee training should be considered when
high open-circuit voltage is present. See 11.2.2.
11.2.3.2 Work Terminal to Grounded Enclosure.
The work shall be grounded in accordance with 11.3.2. In
the case of installations that have followed the practice of
grounding the work lead at a power source terminal, that
itself is grounded by a connection to the grounded power
source enclosure, the power source terminal shall be
connected to the grounded power source enclosure by a
conductor smaller in diameter (at least two wire gages
higher) than the power source enclosure grounding
conductor, and the terminal shall be marked to indicate that
it is grounded. In no case shall a connection between the
work lead terminal and the grounded power source
enclosure be intentionally used instead of the work lead to
carry welding current.
E11.2.3.2 The practice of connecting the work
terminal to the power source enclosure is not
recommended and should be avoided. It is likely for a
welding operator to inadvertently remove the connection
between the work clamp and the work piece and thereby
cause welding current to flow through the grounding
conductors of the electrical system. Measures must be
taken to prevent the flow of welding current through
grounding conductors. Grounding conductors are sized
for other purposes. Welding currents may be too high for
some grounding conductors in the welding area or the
power network.
33
ANSI Z49.1:2012
11.2.3.3 Welding Terminals. Terminals for
welding leads shall be protected from accidental
electrical contact by personnel or by metal objects, for
example, vehicles, crane hooks.
E11.2.3.3 Protection may be obtained by the use of
dead front construction utilizing receptacles for plug
connections, by locating terminals in a recessed opening
or under a nonremovable hinged cover, by heavy
insulating sleeves or by other equivalent mechanical
means to satisfy the requirements.
11.2.3.4 Portable
Control
Devices.
No
connections for portable control devices, such as push
buttons, to be carried by the operator shall be connected
to an ac circuit of higher than 120 volts. Exposed metal
parts of portable control devices operating on circuits
above 50 volts shall be grounded by a grounding
conductor in the control cable.
E.11.2.3.4 See NFPA 79.
11.2.3.5 Autotransformers. Autotransformers or
ac reactors shall not be used to draw welding current
directly from any primary ac power source having a
voltage exceeding 80 volts.
11.2.3.6 Equipment Loading. Care shall be taken
in applying arc welding equipment to ensure that the
ampere rating chosen is adequate to handle the job.
Welding machines shall not be operated above the ampere
ratings and corresponding rated duty cycles as specified
by the manufacturer and shall not be used for applications
other than those specified by the manufacturer.
E11.2.3.6 Using welding machines beyond ampere
or duty cycle ratings causes overheating which results in
premature deterioration of insulation and increases the
electrical shock hazard. Consideration should be given to
the fact that actual welding currents may be higher than
shown by indicators on the machines if welding is done
with short leads or low arc voltages. Particularly high
over-currents are likely on general purpose welding
machines when used with low arc voltage processes such
as gas tungsten arc welding.
11.2.3.7 Welding Cables. Welding cables shall be
of the flexible type designed especially for the rigors of
welding service and of a size adequate for reasonably
expected current and duty cycles. Special attention
shall be paid to the insulation of cables used with
equipment which includes high-voltage, high-frequency
oscillators.
E11.2.3.7 See also 11.2.3.6. Refer to 11.5.4 for
additional information.
11.3 Installation of Arc Welding Equipment
11.3.1 Code Requirements. Installation including
grounding, necessary disconnects, fuses, and type of
incoming power lines shall be in accordance with the
requirements of the current NFPA 70, National Electrical
Code®, and all local codes.
E11.3.2 When the work terminal is grounded, care
should be taken to see that the workpiece is not separately
grounded. Refer to 11.3.2.1. Before welding is attempted
the operator should check to be sure that the worklead is
properly connected. This will eliminate the chance of
welding current being misdirected into the grounding
conductor system of other equipment. Misdirected
welding current can damage conductors which do not
have adequate ampacity. See Article 630.15 of NFPA 70,
National Electrical Code®.
11.3.2 The Work. The workpiece or metal upon
which the welder welds shall be grounded independent of
the welding leads to a good electrical ground unless a
qualified person assures it is safe to work on an
ungrounded workpiece.
34
ANSI Z49.1:2012
11.3.2.1 Grounding. Grounding shall be done by
locating the work on a grounded metal floor or platen, or
by connection to a grounded building frame or other
satisfactory ground. Care shall be taken to avoid the flow
of welding current through a connection intended only
for safety grounding since the welding current may be of
a higher magnitude than the grounding conductor can
safely carry.
E11.3.2.1 The work lead and work lead clamp are
sometimes incorrectly referred to as “ground lead” and
“ground clamp.” The work lead and the ground lead are
not the same. The work lead should not be referred to as
the grounding lead. It is preferable to connect the work
lead directly to the work. Hence, it is inappropriate to
refer to the lead as “ground lead” or the connection as
“ground clamp.” The work clamp should never be stored
by clamping it to any part of the grounded power source
frame. Grounding of electrical systems and circuit
conductors is done to limit voltages due to lightning, line
voltage surges, or unintentional contact with higher
voltage lines, and to stabilize voltage to ground during
normal operations.
It also facilitates over-current device operation in case of
ground faults. (See Article 250.4 of NFPA 70, National
Electrical Code®.) Grounding of workpieces, equipment
housings, metal cabinets and frames, or other conductive
material that form part of the equipment is done to limit
the voltage to ground on these items. Limiting the voltage
by grounding helps to prevent accidental shocks when
equipment is misconnected or insulation fails. (See
Article 250.4 of NFPA 70, National Electrical Code®.)
Equipment used with ungrounded supply systems, such
as is used in naval shipboard systems, should be connected in accordance with the requirements of the authority having jurisdiction.
Special radio frequency grounding may be advisable for
equipment using high-frequency arc stabilizers. (See
Recommended Installation and Test Procedures for High
Frequency Stabilized Arc Welders, 1970, Arc Welding
Section of NEMA.)
E11.3.2.2 Refer to 11.3.6 for voltage and shock
consideration. With the permissible alternate procedure,
care should be taken that no other electrical connection or
path exists.
11.3.2.2 Work Lead. Welding current shall be
returned to the welding machine by cable with sufficient
current capacity. However, connection of a cable from
the welding machine to a common conductor or properly
bonded structure on which the work rests, or to which the
work is connected, shall be a permissible alternate
procedure. Single-phase alternating current machines in
groups of three with their inputs connected in delta to a
three-phase supply circuit connected in wye on the
secondary circuits shall be permitted to use a single work
lead from the neutral of the three units to the structure
being welded.
The work lead shall use a single cable of a size suitable
for the current rating of at least one machine.
E11.3.3 Current which passes through joints which are
not intended for such use can cause hot spots to develop.
These hot spots can lead to the development of hidden
fires or explosions. For other precautions, see 11.4.
11.3.3 Conduit and Pipe Ground Limitations.
Conduits containing electrical conductors shall not be
used for completing a work lead circuit. Pipelines shall
not be used as a permanent part of a welding circuit, but
may be used during construction, extension, or repair
providing the current is not carried through threaded
35
ANSI Z49.1:2012
joints, flanged bolted joints, or caulked joints. In addition,
special precautions shall be used to avoid sparking at the
connection of the work lead cable.
11.3.4 Prohibited Work Lead Connection. Chains,
wire ropes, cranes, hoists, and elevators shall not be used
to carry welding current.
E11.3.4 See 11.4.9.2.
11.3.5 Electrical Continuity in Structures. When
during construction or modification, a building or any
other fabricated metal structure is used for a welding
current return circuit, it shall be checked to ascertain
whether proper electrical contact exists at all joints.
Sparking or heating at any point shall be cause for
rejection of the structure as a return circuit.
E11.3.5 Approval should be obtained from the owner
or responsible person before proceeding.
11.3.6 Connections to Minimize Shock Hazard.
Where welders are working on one structure, sufficiently
close to each other, and someone is likely to touch the
exposed parts of more than one electrode holder
simultaneously, machines shall be connected to minimize
shock hazard as follows:
11.3.6.1 DC Machines. Unless required by special
cases, all dc machines shall be connected with the same
polarity.
E11.3.6.1 A test lamp or voltmeter may be used to
determine whether the connections are correct. See
11.3.6.3
11.3.6.2 AC Machines. Unless required by special
cases, all single-phase ac machines shall be connected to
the same phase of the supply circuit and with the same
instantaneous polarity.
E11.3.6.2 A voltmeter can be used to determine
whether the connections are correct. See 11.3.6.3.
11.3.6.3 Special Cases. The operator and other
area personnel shall be instructed on of the importance of
avoiding simultaneous contact of the exposed parts of
more than one electrode holder.
E11.3.6.3 When operations on one structure
involve several welding machines, the dc welding
process requirements may require the use of both
polarities, or supply circuit limitations for ac welding
may require distribution of machines among the phases
of the supply circuit. No-load voltages between electrode
holders will be two times normal in dc or 1, 1.41, 1.73, or
two times normal on ac machines. Similar voltage
differences will exist if both ac and dc welding are done
on the same structure.
11.4 Operation
E11.4 This section applies to all arc welding and cutting
processes. For gas shielded arc welding, see also
recommended practice documents such as AWS C5.6-89,
Recommended Practices for Gas-Metal Arc Welding.
11.4.1 Worker Instruction. Workers assigned to
operate or maintain arc welding equipment shall be
acquainted with those parts of this standard applicable to
their work assignments.
E11.4.1 Those sections of particular interest are
Clause 4, Protection of Personnel and the General Area;
Clause 5, Ventilation; and Clause 6, Fire Prevention and
Protection.
11.4.2 Checking Connections. After assembling any
connection to the machine, each assembled connection
shall be checked before starting operations to ascertain
that it is properly made. In addition, the work lead shall
be firmly attached to the work; magnetic work clamps
shall be freed from adherent metal particles and spatter on
contact surfaces.
E11.4.2 Clean and tight connections are necessary to
prevent local heating. Properly insulated and dry
connections are necessary to prevent stray electrical
currents and possible shock or short circuits.
Coiled welding cable should be kept to a minimum
and any excess is to be spread out before use to avoid
36
ANSI Z49.1:2012
overheating and damage to insulation. Jobs alternately
requiring long and short cables should be equipped with
insulated connectors so that idle lengths can be disconnected when not needed.
11.4.3 Machine Frame Grounding. Grounding of
the welding machine frame shall be checked. Special
attention shall be given to safety grounding connections
of portable machines. See NFPA 70, National Electric
Code®, Article 250, Grounding.
E11.4.4 Moisture can carry electric current and increase
the chance of electric shock, shielding gases can cause
asphyxiation, and fuels can cause explosions or fires.
11.4.4 Leaks. There shall be no leaks of cooling
water, shielding gas, or engine fuel that can adversely
affect the welder’s safety.
11.4.5 Safe Operating Instructions. Written rules
and instructions covering the safe operation of equipment
shall be made available to the welder and shall be strictly
followed.
11.4.6 Work Interruptions. When the welder leaves
the work or stops for an appreciable time, the equipment
or machine output shall be turned off or de-energized.
11.4.7 Moving the Machine. When the machine is to
be moved, the input power supply to the equipment shall
be electrically disconnected.
11.4.8 Equipment Not in Use. When not in use,
metal and carbon electrodes shall be removed from
holders to eliminate danger of electrical contact with
persons or conducting objects. When not in use, electrode
holders shall be so placed that they cannot make electrical
contact with persons, conducting objects, such as metal
or wet earth, flammable liquids, or compressed gas
cylinders. When not in use, guns of semiautomatic
welding machines shall be placed so that the gun switch
cannot be operated accidentally.
E11.4.9 Conductive articles of jewelry and clothing
(such as watch bands, bracelets, rings, key chains,
necklaces, metalized aprons, cloth with conductive
thread, or metal headgear) should not be worn if they
might contact exposed energized parts. However, such
articles may be worn if they are rendered nonconductive
by covering, wrapping, or other insulating means.
11.4.9 Electric Shock. The welder shall be trained to
avoid shock. Unexplained shocks shall be reported to the
supervisor for investigation and correction prior to
continuing. Safe procedures shall be observed at all times
when working with equipment having voltages necessary
for arc welding.
11.4.9.1 Live Metal Parts. The welder shall never
permit the live metal parts of an electrode, holder, or
other equipment, to touch bare skin or any wet covering
of the body.
11.4.9.2 Insulation. Welders shall protect
themselves from electrical contact with the work or
ground by dry insulating material; particularly, they shall
be protected against large area contacts by insulation
when working in a sitting or prone position.
E11.4.9.2 When the worker is required to be on a
ladder while welding or cutting, the ladder should be
nonconductive or otherwise insulated from work and
ground. Dry shoes in good condition should be worn.
Rubber soled shoes or boots should be worn in damp
areas. Workers should wear protective boots when
working in standing water or other wet areas.
37
ANSI Z49.1:2012
To reduce the possibility of welding current arcing
through the suspension wire rope when performing welding from suspended scaffolds, use an insulated thimble to
attach each suspension wire rope to its hanging support
(such as cornice hook or outrigger). Insulate excess suspension wire rope and insulate any additional independent lines from grounding. Cover the suspension wire
rope with insulating material extending at least 4 feet
above the hoist. Insulate the tail line below the hoist to
prevent contact with the platform. Guide or retain the
portion of the tail line that hangs free below the scaffold
so that it does not become grounded (see 29 CFR
1926.451(f)(17)).
11.4.9.3 Gloves. Dry gloves in good condition
shall be used.
E11.4.9.3 Use of damp or wet gloves may lead to
electric shock. Where moisture or perspiration is a
problem, rubberized gloves or other insulating means
should be used. See also 4.3.2 and E11.2.2.
11.4.9.4 Holders and Guns. Electrode holders
and guns shall be well insulated and kept in good repair.
11.4.9.5 Water Immersion. Electrode holders
and guns shall not be cooled by immersion in water.
11.4.9.6 Water-Cooled Holders. Water-cooled
holders and guns shall not be used if any water leak or
condensation exists which would adversely affect the
welder’s safety.
11.4.9.7 Changing Electrodes. Except for
shielded metal arc welding, the output of the welding
machine shall be electrically de-energized when
electrodes or contact tips are changed.
11.4.9.8 Other Practices to Avoid. The welder
shall not coil or loop welding electrode cable around parts
of the body. Precautions shall be taken to prevent shockinduced falls when the welder is working above ground
level.
E11.4.9.9 Welders and other persons who must
work in a welding environment should inform their doctors
prior to undergoing device installation procedures.
11.4.9.9 Wearers of Pacemakers. Wearers of
pacemakers or other electronic equipment vital to life
shall check with the life support manufacturers and their
clinician to determine whether a hazard exists.
11.5 Maintenance
E11.5.1
Periodic
recommended.
11.5.1 General. All arc welding equipment shall be
maintained in safe working order at all times. The welder or
maintenance personnel shall report any equipment defect or
safety hazard to the supervisor, and the use of such
equipment shall be discontinued until its safety has been
assured. Repairs shall be made by qualified personnel only.
11.5.2 Welding Equipment. Welding equipment
shall be maintained in good mechanical and electrical
condition to avoid unnecessary hazards. On rotating
electrical equipment, commutators shall be kept clean to
prevent excessive flashing.
38
inspections
are
strongly
ANSI Z49.1:2012
11.5.2.1 Inspection. Welding equipment shall be
inspected frequently to detect accumulations of foreign
matter that would interfere with ventilation or insulation.
Electrical coil ventilation ducts shall be similarly
inspected and cleaned. Fuel systems on engine-driven
machines shall be inspected and checked for possible
leaks and accumulations of water that might cause
rusting. Rotating and moving components shall be kept
properly shielded and lubricated.
E11.5.2.1 Dirt on electrical equipment can increase
temperature, decrease service life, and possibly lead to
short circuiting.
11.5.2.2 Welding in the Open. Welding
equipment used in the open shall be protected from
inclement weather conditions. Protective covers shall not
obstruct the ventilation necessary to prevent overheating
of the machine.
E11.5.2.2 Air filters in the ventilating system of the
electrical components should not be used unless provided
by, or approved by, the manufacturer of the welding
machine. The reduction of air flow resulting from the use
of an air filter on equipment not so designated can subject
internal components to an overheating condition and
subsequent failure.
11.5.2.3 Modifications. When it is necessary to
modify equipment, such as in order to meet noise level
requirements, it shall be determined that the
modifications or additions to the equipment do not cause
the electrical or mechanical ratings to the equipment to be
exceeded or overloaded.
E11.5.2.3 Modifications should only be performed
by the equipment manufacturer or a qualified service
technician.
It is good practice to blow out the entire welding machine
with clean dry compressed air using adequate safety
precautions.
11.5.3 Wet Machines. Machines which have become
wet shall be thoroughly dried and properly tested before
being used. When not in use, the equipment shall be
adequately protected or stored in a clean, dry place.
E11.5.4 Disconnected welding cable leads should be
properly stored to prevent inadvertent completion of
electrical circuits.
11.5.4 Welding Cable. Welding cable shall be
inspected for wear or damage. Cables with damaged
insulation or connectors shall be replaced or repaired to
achieve the mechanical strength, insulating quality,
electrical conductivity, and water tightness of the original
cable. Joining lengths of cables shall be done by methods
specifically intended for the purpose. The connection
methods shall have insulation adequate for service.
11.5.5 Compressed Gases. Use of compressed gases
for shielding in arc welding operations shall follow the
applicable provisions of Clause 10, Oxyfuel Gas Welding
and Cutting Safety.
12. Resistance Welding Safety
12.1 General
12.1.1 Scope. The scope of this section is limited to
welding equipment using resistance welding principles
as defined in the AWS publication entitled AWS
A3.0M/A3.0, Standard Welding Terms and Definitions.
Users are further referred to Part I herein which is
applicable to general safety in welding and cutting.
12.1.2 Selection. All resistance welding equipment
shall be selected for safe application to the work
39
ANSI Z49.1:2012
intended. The personnel safety aspects of resistance
welding shall be given consideration when choosing
equipment for the work to be performed.
E12.1.3 Refer to OSHA 29 CFR 1910.225.
12.1.3 Operator Training. Workers designated to
operate resistance welding equipment shall have been
properly instructed and judged competent to operate such
equipment.
12.2 Installation. All equipment shall be installed in
conformance with NFPA 79, Electrical Standard for
Industrial Machinery, NFPA 70E, Standard for
Electrical Safety in the Workplace®, and NFPA 70
National Electrical Code® or their equivalent in
protection based on advances in technology. The
equipment shall be installed by qualified personnel under
the direction of a technical supervisor.
E12.2 Refer to OSHA 29 CFR 1910 Subpart S,
Electrical.
12.3 Guarding
12.3.1 Control Initiating Devices. Control initiating
devices such as push buttons, foot switches, retraction
systems, and dual schedule switches on all welding
equipment including manual guns shall be arranged or
guarded to prevent the operator from inadvertently
activating them.
12.3.2 Stationary Equipment
12.3.2.1 General. All chains, gears, operating
linkages, and belts associated with welding equipment
shall be protected in accordance with ANSI B15.1, Safety
Standard for Mechanical Power Transmission Apparatus.
12.3.2.2 Single-Ram
and
Single-Point
Equipment. On stationary single-ram welding machines,
unless the workpiece size, configuration, or tooling (e.g.,
jig or fixture) occupies both of the operator’s hands
remotely from the point of operation during the machine
cycle, operations shall be in a manner preventing injury
to the operator by one or a combination of the following:
(1) Machine guards or fixtures preventing the operator’s hands from passing under the point of operation;
(2) Two-handed controls;
(3) Latches;
(4) Presence sensing devices; or
(5) Any similar device or mechanism preventing
operation of the ram while the operator’s hands are under
the point of operation.
12.3.2.3 Multi-Gun Equipment. All multi-gun
welding machine operations, when the operator’s fingers
can be expected to pass under the point of operation, shall
be effectively guarded by the use of a device, such as but
not limited to, presence sensing devices, latches, block,
barriers, or two-handed controls.
12.3.3 Portable Equipment
12.3.3.1 Support System Safety. All suspended
manual gun equipment, with the exception of the manual
40
ANSI Z49.1:2012
gun assembly, shall be equipped with a support system
capable of supporting the total impact load in the event of
failure of any component of the supporting system. The
system shall be designed to be fail safe. The use of devices
such as cables, chains, clamps, etc. shall be permitted.
12.3.3.2 Moving Holder. Where it enters the gun
frame, the moving holder mechanism shall be designed
so as to present no shear points to the fingers placed on
the operating movable holder, otherwise guarding shall
be provided. If suitable guarding cannot be achieved, the
use of two handles, one for each hand with one or two
operating switches located at appropriate holding points
shall be permitted to be used. These handles and
operating switches shall be sufficiently remote from the
shear or pinch point, or both, to eliminate the possibility
of any finger entering the shear or pinch point when the
hands are on the controls.
12.4 Electrical
12.4.1 Voltage. All external weld-initiating control
circuits shall operate not over 120 volts ac rms for
stationary equipment, and not over 36 volts ac rms for
portable equipment.
12.4.2 Stored Energy Resistance Welders
12.4.2.1 Maintenance and Service. When
servicing stored energy welding machines, maintenance
personnel shall not rely on the existence of energy
dissipation means or energy indicators and shall always
use a safe method to verify the stored energy has been
dissipated before servicing the equipment.
12.4.2.2 Stored Energy Resistance Welders,
Equipment and Controls. Resistance welding
equipment and control panels containing devices such as
capacitors, inductors, and batteries for stored energy
resistance welding shall have suitable insulation and
protection by complete enclosures, all doors of which
shall be provided with suitable interlocks and contacts
wired into the control circuit (similar to elevator
interlocks). Such interlocks or contacts shall be so
designed as to effectively interrupt power and ensure the
stored energy is dissipated (for inductors and capacitors)
or isolated (for batteries) as appropriate when the
enclosure door is open.
A manually operated switch or suitable positive device
shall be installed in addition to the mechanical interlocks
or contacts, as an added safety measure assuring absolute
discharge of all capacitors.
The stored energy welder shall contain a means to determine the condition of stored energy such as insulated test
points. Appropriate precautionary labeling regarding this
stored energy shall be used.
41
ANSI Z49.1:2012
The control panel itself is considered an enclosure and
capacitors located inside such a panel box shall not need
further enclosure when the other requirements of the
paragraph are met.
12.4.3 Inverter-based Welding Machines
12.4.3.1 Maintenance and Service. When
servicing medium frequency direct current (MFDC)
resistance welding controls and high frequency direct
current welding (HFDC) resistance welding controls,
maintenance personnel shall not rely on the existence of
filter capacitor dissipation means and shall always use a
safe method to verify that the capacitors have been
dissipated before servicing the equipment.
12.4.3.2 Inverter-based Controls. Machines
incorporating MFDC resistance welding controls and
HFDC resistance welding controls may incorporate large
filter capacitors, which store hazardous amounts of energy.
These controls must comply with the requirements of
NFPA 79, Electrical Standard for Industrial Machinery.
The MFDC and HFDC controls shall contain a means to
determine the condition of the filter capacitors such as
insulated test points. Appropriate precautionary labeling
shall also be used to advise of this voltage hazard.
12.4.4 Locks and Interlocks
12.4.4.1 Doors. The doors and access panels of all
resistance welding machines and the control panels,
accessible at production floor level, shall be kept locked
or interlocked to prevent access by unauthorized persons
to live portions of the equipment. A door or access panel
shall be considered locked if a key, wrench, or other
instrument is required to open it.
12.4.4.2 Remotely Located Control Panels.
Control panels located on overhead platforms or in
separate rooms shall be either locked, interlocked, or
guarded by a physical barrier and signs, and the panels
closed when the equipment is not being serviced. Signs
shall be in accordance with ANSI Z535 Standards.
For flash welding equipment, flash guards of suitable fire
resistant material shall be provided to control flying
sparks and molten metal.
12.4.5 Spark Shields. Protection shall be provided
from the hazard resulting from flying sparks by methods
such as the installation of a guard of suitable fire resistant
material or the use of approved personal protective eye
wear. The variations in resistance welding operations are
such that each installation shall be evaluated individually.
E12.4.5 The primary intent is the protection of
personnel other than the operator whose protection is
discussed in Clause 4, Protection of Personnel and the
General Area. Suitable precautions shall be taken to
avoid fires as set forth in Clause 6, Fire Prevention and
Protection.
12.4.6 Stop Buttons. One or more safety emergency
stop buttons shall be provided on all welding machines
that have the following characteristics:
E12.4.6 The term sequence as used here means the
action and time required by the machine from the time the
run buttons are locked in (interlocked) and can be
released, until the machine stops of its own accord.
42
ANSI Z49.1:2012
(1) require three or more seconds to complete a
sequence,
(2) have mechanical movements that can be hazardous to persons if guards were removed, and
(3) installation and use of these emergency stop buttons will not in themselves create additional hazards to
persons.
12.4.7 Grounding.
E12.4.7 Undesirable circulating currents can flow
through the fixture or workpiece when permanent
grounding is employed within systems incorporating
multiphase primary supplies, different secondary
voltages, or both. Such situations will require use of a
grounding reactor (for ac machines), a grounding resistor
(for dc machines) or isolation contactor (when there is no
human interaction with the secondary circuit or its
associated tooling).
12.4.7.1 General Grounding of Resistance
Welders. The welding transformer secondary shall be
bonded to a protective ground by one of the methods in
(1), (2), (3) below, or an alternative means of protection
shall be provided as in (4) below:
(1) Permanent grounding of the welder secondary
circuit using an appropriately sized conductor.
(2) Bonding of the dc welder secondary circuit
through a properly sized resistor.
(3) Connecting a grounding reactor across the secondary winding with reactor tap(s) to ground.
(4) As an alternative, on machines where, under normal operation, these is no human interaction with the secondary circuit or its associated tooling, provide for an
isolation contactor to open both sides of the line to the
primary of the welding transformer. When this method is
employed, appropriate care shall be taken during maintenance procedures, such as the welding of test coupons, to
ensure that personnel are protected from fault currents.
12.4.7.2 Grounding of Portable Transguns. In
addition to the requirements of 12.4.7.1, manual guns
incorporating an integral resistance welding transformer
with primary voltage in excess of 120 volts require
supplemental means to ensure operator protection. Such
supplemental means shall include as a minimum:
(1) Ground fault detection which will disconnect the
supply in the event of a fault.
(2) Ground connection verification.
(3) A grounded shield primary cable to provide supplemental mechanical and electrical protection.
(4) A means to verify the operation of the safety
systems.
E12.4.7.2 Operators and maintenance personnel
will require additional training on the operation and
maintenance of this equipment and there should be a
regular schedule of inspection to ensure the safety
equipment is operating as intended.
12.5 Static Safety Devices. On large welding machines
incorporating a platen, electrically interlocked safety
devices such as pins, blocks, or latches, shall be provided
where the platen or the head can move. The device, when
used, shall cause the energizing circuit to be broken, and
E12.5 The intent is to require these devices when the
machine area is so large that the maintenance or setup
would require the insertion of more than hands into the
closure area.
43
ANSI Z49.1:2012
the device itself will prevent movement of the platen or
head under static load. More than one device may be
required, varying with machine size or accessibility, but
each device alone shall be capable of sustaining the full
static load involved.
12.6 Ventilation. Ventilation shall be provided in
accordance with Clause 5.
12.7 Maintenance. Periodic inspections and necessary
repairs shall be made by authorized personnel. The
operators or maintenance personnel shall report any
equipment defects to supervisory personnel.
13. Electron Beam Welding and
Cutting Processes (EBW and
EBC)
13.1 General. These safe practice recommendations are
abstracted from the AWS C7.1, Recommended Practices
for Electron Beam Welding.
E13.1 AWS C7.1 should be consulted for a complete
treatise of the subject. Also, refer to Part I of this standard
for general safety considerations associated with welding
and cutting processes and equipment.
13.2 Potential Hazards. The following potential
hazards associated with electron beam welding shall be
guarded against:
Electric Shock (13.2.1)
Gases and Fumes (13.2.2)
X-radiation (13.2.3)
Visible Radiation (13.2.4)
Vacuum (13.2.5)
13.2.1 Electric Shock. Appropriate precautionary
signs shall be affixed to the equipment. All doors and
access panels on electron beam welding equipment shall
be properly secured and interlocked to prevent accidental
or unauthorized access. All high-voltage conductors shall
be fully enclosed by grounded, conductive barriers that
are also interlocked. A grounding probe shall be used
before servicing the electron beam gun and high-voltage
power supplies.
E13.2.1 The typical primary voltage to an electron
beam welding machine is 440 volts. Voltages used in the
electron beam welding processes are much higher than
those in most welding processes.
13.2.2 Gases and Fumes. Positive exhaust
ventilation and filtering from the medium and nonvacuum
EB processes shall be provided. In high-vacuum EB
welding, extra care shall be taken while cleaning the
interior of the vacuum chamber to ensure that vapors from
the solvents and cleaning solutions do not reach
hazardous levels.
E13.2.2 Ozone, nitrogen oxides, and metal fumes are
generated by electron beam welding. See 3.2.1.2 for more
information on handling of hazardous substances, Clause
5, Ventilation, for a detailed description of adequate
ventilation systems, and Clause 7, Confined Spaces, for
information on working in confined spaces.
Whenever servicing (especially on energized systems) is
done on this equipment, a second person should be in the
area in case of accidental shock. The primary input voltage
is stepped up to several thousand volts for the electron
beam gun and also for the vacuum (ionization) gauge(s).
These voltages, and their associated currents, are lethal.
Before welding any unfamiliar materials or using any
unfamiliar cleaning materials, the Material Safety Data
Sheet (MSDS) shall be read to determine whether any
hazards exist.
44
ANSI Z49.1:2012
13.2.3 X-radiation. Proper shielding of EBW
equipment is required to eliminate, or reduce to
acceptable levels, x-radiation in the workplace. Any
modifications to radiation shielding shall be performed
only by the equipment manufacturer or a qualified service
technician. A radiation survey shall be done after
modifications are completed by the equipment
manufacturer or qualified technicians.
E13.2.3 X-radiation is produced when electrons
collide with a substance (such as a gas or metal). The
intensity of the x-rays produced increases with increasing
beam voltage, beam current, and the atomic number of
the material being struck by the beam. The electron beam
equipment should be inspected and a radiation survey
made periodically with the results documented and
posted. Publications such as ANSI N43.3, General Safety
Standards for Installations Using Non-Medical X-Ray
and Sealed Gamma Ray Sources, Energies Up to 10 MeV,
and AWS C7.1M/C7.1, Recommended Practices for
Electron Beam Welding, should be consulted for typical
precautions and survey procedures that should be
followed in order to provide adequate protection.
13.2.4 Nonionizing Radiation. The leaded glass
used in the viewing ports shall provide sufficient optical
viewing protection from the UV and IR radiation, and
appropriate filters shall be selected and used to reduce the
visible light to a comfortable viewing level.
E13.2.4 Direct viewing of the weld zone during
electron beam welding can be harmful to the eyesight
since visible, infrared (IR), and ultraviolet (UV) radiation
are produced. See also 4.2.2. ANSI Z87.1, Occupational
and Educational Eye and Face Protection Devices,
should be consulted for guidance in the selection of
optical filters.
13.2.5 Vacuum. Users of the electron beam welding
process shall be aware of the precautions required for
working with vacuum systems.
E13.2.5 All electron beam welding machines
require a high vacuum for beam generation. In addition,
most machines require some level of vacuum
environment for the workpiece. User should be aware
that high levels of noise can be generated by EBW
vacuum systems. A detailed description of these
precautions is provided by the American Vacuum Society
publication Vacuum Hazards Manual.
14. Laser Beam Cutting and Welding
14.1 General. Cutting and welding operations using
laser beam technology shall follow the applicable
sections of this standard and ANSI Z136.1, Safe Use of
Lasers.
15. Brazing and Soldering Safety
15.1 General. This section addresses safe practices for
brazing and soldering.
E15.1 The hazards encountered with brazing and
soldering are similar to those associated with the welding
and cutting processes. The safe practices implemented for
welding and cutting are equally applicable to brazing and
soldering regarding the Protection of Personnel and the
General Area, Ventilation, Fire Prevention and Protection,
and Confined Spaces (see Clauses 4, 5, 6, and 7).
15.2 Potential Hazards. When conducting brazing and
soldering operations, the following potential hazards
shall be guarded against:
45
ANSI Z49.1:2012
(1)
(2)
(3)
(4)
(5)
flammable and corrosive substances (see 15.2.1);
burns (see 15.2.2);
fluxes and filler metals (see 15.2.3);
gases and fumes (see 15.2.4); and
equipment maintenance (see 15.2.5).
15.2.1 Flammable and Corrosive Substances.
Operators shall isolate containers of alcohol-based or
alcohol-containing flux solutions from open flames and
heat sources during assembly as well as when in storage.
As fluxes are corrosive substances, they shall be stored,
transported, and disposed of in accordance with
regulatory practices for acidic materials. Operators shall
wear proper eye protection, face guard, and protective
clothing during the transport, handling, and use of fluxes.
The material safety data sheets for flammable and
corrosive substances shall be consulted before these
substances are used.
E15.2.1 Numerous fluxes for structural and electronic
applications contain alcohol as the vehicle or as a diluting
agent, causing the fluxes to be highly flammable.
Moreover, fluxes are corrosive materials. The level of
corrosivity ranges from very mild (e.g., pure rosin) to
highly active (e.g., solutions of hydrochloric acid, nitric
acid, and so forth); however, even the mild acids can
cause burn injuries to the operator. Some stop-off
materials, cements, and binders contain solvents and are
flammable.
Brazing furnace atmospheres shall be purged using safe
procedures before the introduction of flammable gases
(these include fuel gases, hydrogen, and dissociated
ammonia) often used as atmospheres (see 5.5.6).
15.2.2.1 Marking Hot Materials. Operators shall
label all assemblies, tools, and surfaces that are at high
temperatures with the appropriate sign (see 3.2.3.4).
E15.2.2.1 High temperatures are those
temperatures at which the particular item cannot be
carried by the bare hand.
15.2.2.2 Dip Brazing. When dip brazing,
assemblies and fixtures to be immersed in the molten salt
bath shall be completely dry.
E15.2.2.2 Any presence of moisture on the
assemblies or fixtures will cause an instantaneous
generation of steam that may expel the contents of the dip
pot with explosive force to create a serious burn hazard.
15.2.2.3 Aluminum. Operators shall take
precautions when handling aluminum to prevent serious
burns from very hot assemblies.
E15.2.2.3 When aluminum is very hot, it does not
change color like steel does; thus, hot aluminum is
deceptive.
15.2.2.4 Hydrogen.
Operators
shall
take
precautions when using hydrogen as a fuel gas to prevent
burns to the personnel.
E15.2.2.4 Flames of burning hydrogen are almost
invisible.
15.2.3 Fluxes and Filler Metals. Operators shall
remove all food (including coffee, soft drinks, and other
beverages) from the work area in which brazing filler
metals, solder alloys, and fluxes are being handled.
Casual contact between the hands, face, nose, or mouth
shall be avoided when handling filler metals, solder,
fluxes, or base materials. Gloves shall be worn when
possible. The material safety data sheets for brazing
fluxes and filler metals shall be consulted before these
substances are used.
E15.2.3 Solder typically contains heavy metals (e.g.,
antimony, lead, silver, and so forth) that are toxic to
humans. The ingestion of small amounts of these metals
over extended periods can cause chronic health
complications.
15.2.4 Gases and Fumes. Operators shall use
adequate ventilation during brazing and soldering
procedures (see Clause 5). Nonevacuated furnaces shall
be purged following brazing or soldering processes to
remove harmful fumes prior to the removal of assemblies.
E15.2.4 Temperatures can be used that cause some
elements in the filler metal to vaporize. Elements, such as
antimony, beryllium, cadmium, lead, or mercury are
toxic materials. Zinc fumes can cause metal fume fever.
Some filler metals contain suspected carcinogens such as
nickel and chromium. These can oxidize at high
46
ANSI Z49.1:2012
temperature and create hazardous fumes. Fluxes that
contain chemical compounds of fluorine or chlorine are
harmful if they are inhaled or they contact the skin. The
application of heat to fluxes and filler metals can generate
toxic gases and fumes. Stop-off materials are generally
fine ceramics and should be considered a dust particulate
material.
15.2.5 Equipment Maintenance
E15.2.5.1 Protection is especially important when
cleaning the assembly. Even though the solvent may
be harmless (e.g., tap water), it quickly becomes
contaminated with flux residues, thereby forming caustic
or acidic solutions that can impair vision or cause skin
burns. This danger is especially prevalent during the
drying phase of the cleaning step, which may use highpressure gases (e.g., compressed air or nitrogen) to
displace the liquid cleaning agent from the assembly.
15.2.5.1 Cleaning. Suitable eye, face, and body
protection shall be worn by operators when cleaning
assemblies with any solvent, including tap water. Gloves
shall be worn to prevent injury from acidic or caustic
residues generated in the cleaning agent as well as the
possible ingestion of metals rubbed off joints and base
material.
Operators shall dispose of all cleaning solutions in accordance with environmental regulations and corporate procedures.
15.2.5.2 Removal of Magnesium Buildup. The
buildup of magnesium from brazing furnaces shall be
removed periodically. Protective clothing (i.e., fireresistant jackets, pants, and gloves) shall be used as well
as adequate ventilation or respirators (see 5.4) to prevent
the inhalation of magnesium and magnesium oxide dust
accumulated during the scraping operation.
E15.2.5.2 Magnesium, a highly flammable metal,
is added to brazing filler metals to facilitate aluminum
brazing.
Nonsparking tools shall be used to scrape the magnesium
and magnesium oxide off the walls and other internal
parts of the furnace. At regular intervals, the accumulated
debris shall be put into a metal box and removed from the
furnace area to prevent igniting the magnesium by an
accidental spark.
The area around the furnace shall be kept clean at all
times. Several pails of sand and the proper fire extinguisher shall be available to extinguish possible magnesium fires. Under no circumstances shall water be used to
extinguish a magnesium fire. At no time shall any one
person work alone on this removal procedure. Another
person shall always be present in the immediate area in
case of an accidental fire.
47
ANSI Z49.1:2012
Annex D (Informative)
Master Chart of Welding and Joining Processes and
Master Chart of Allied Processes
(from AWS A3.0M/A3.0:2010, Standard Welding Terms and Definitions)
This annex is not part of ANSI Z49.1:2012, Safety in Welding, Cutting,
and Allied Processes, but is included for informational purposes only.
Master Chart of Welding and Joining Processes
48
ANSI Z49.1:2012
Master Chart of Allied Processes
49
REMEMBER
SAFETY IS
GAINFUL ,
ACCIDENT IS
PAINFUL
50
SAFETY QUICK GUIDE
51
Safety Quick-Guide
01
Weld Cable Selector Guide*
Turn Off power before connecting
to weld output terminals.
Do not use worn, damaged, undersized, or repaired cables.
Electrode
Work
NOTICE − The Total Cable Length in Weld Circuit (see table below) is the combined length of
both weld cables. For example, if the power source is 100 ft (30 m) from the workpiece, the total
cable length in the weld circuit is 200 ft (2 cables x 100 ft). Use the 200 ft (60 m) column to determine cable size.
Weld Cable Size** And Total Cable (Copper) Length
In Weld Circuit Not Exceeding***
100 ft (30 m) Or Less
150 ft
(45 m)
200 ft
(60 m)
Welding
Amperes
10 − 60% Duty
Cycle
60 − 100%
Duty Cycle
100
4
4
4
3
150
3
3
2
1
200
3
2
1
1/0
250
2
1
1/0
2/0
300
1
1/0
2/0
3/0
350
1/0
2/0
3/0
4/0
400
1/0
2/0
3/0
4/0
500
2/0
3/0
4/0
2 ea. 2/0
600
3/0
4/0
2 ea. 2/0
2 ea. 3/0
700
4/0
2 ea. 2/0
2 ea. 3/0
2 ea. 4/0
800
4/0
2 ea. 2/0
2 ea. 3/0
2 ea. 4/0
900
2 ea. 2/0
2 ea. 3/0
2 ea. 4/0
3 ea. 3/0
1000
2 ea. 2/0
2 ea. 3/0
2 ea. 4/0
3 ea. 3/0
1250
2 ea. 3/0
2 ea. 4/0
3 ea. 3/0
4 ea. 3/0
10 − 100% Duty Cycle
*This chart is a general guideline and may not suit all applications. If cable overheating occurs
(normally you can smell it), use next size larger cable.
**Weld cable size (AWG) is based on either a 4 volts or less drop or a current density of at least
300 circular mils per ampere. Contact your distributor for the mm2 equivalent weld cable sizes.
52
Safety Quick-Guide
02.
Lens Shade Selector Guide
Electrode Size
in. (mm)
Arc Current
(Amperes)
Minimum
Protective
Shade
Suggested*
Shade No.
(Comfort)
Less than 3/32 (2.5)
3/32−5/32 (2.5−4)
5/32−1/4 (4−6.4)
More than 1/4 (6.4)
Less than 60
60−160
160−250
250−550
7
8
10
11
—
10
12
14
Gas metal arc
welding (GMAW) and
flux cored arc
welding (FCAW)
Less than 60
60−160
160−250
250−550
7
10
10
10
—
11
12
14
Gas tungsten arc
welding (GTAW)
Less than 50
50−150
150−500
8
8
10
10
12
14
Less than 500
500−1000
10
11
12
14
Plasma arc welding
(PAW)
Less than 20
20−100
100−400
400−800
6
8
10
11
6 to 8
10
12
14
Plasma arc cutting
(PAC)
Less than 20
20−40
40−60
60−80
80−300
300−400
400−800
4
5
6
8
8
9
10
4
5
6
8
9
12
14
Torch brazing (TB)
—
—
3 or 4
Torch soldering (TS)
—
—
2
Carbon arc welding
(CAW)
—
—
14
Operation/Process
Shielded metal arc
welding (SMAW)
Air carbon arc cutting
(CAC−A)
(Light)
(Heavy)
Plate thickness
in.
mm
Oxyfuel gas welding
(OFW)
Light
Medium
Heavy
Under 1/8
1/8 to 1/2
Over 1/2
Under 3.2
3.2 to 12.7
Over 12.7
4 or 5
5 or 6
6 or 8
Oxygen Cutting (OC)
Light
Medium
Heavy
Under 1
1 to 6
Over 6
Under 25
25 to 150
Over 150
3 or 4
4 or 5
5 or 6
* As a rule of thumb, start with a shade that is too dark to see the weld or cut zone. Then go to a lighter shade
which gives sufficient view of the weld or cut zone without going below the minimum. In oxyfuel gas welding,
cutting, or brazing where the torch produces a high yellow light, it is desirable to use a filter lens that absorbs
the yellow or sodium line in the visible light of the (spectrum) operation.
Guide adapted from ANSI Z49.1, 2005.
Low Current Plasma arc cutting data (0−80 Amperes) supplied by Miller Electric Mfg. Co.
53
Safety Quick-Guide
Hot parts can burn.
Do not touch hot welded or cut parts with bare hand. If handling is needed, use proper tools
and/or wear heavy, insulated welding gloves to prevent burns.
Allow cooling period before handling parts or working on equipment.
Falling equipment can injure, and damage
equipment.
Use lifting eye to lift unit only, NOT running gear, gas cylinders, trailer, or any other accessories.
Use equipment of adequate capacity to lift and support unit.
If using lift forks to move unit, be sure forks are long enough to extend beyond opposite side
of unit.
Do not place unit where it may easily tip over or fall.
Battery charging output and battery explosion
can injure.
Sparks can cause battery gases to explode.
Do not smoke and keep matches and flames away from battery.
Wear a face shield or safety glasses when working near or on a battery.
Do not use welder or plasma cutter to charge batteries or jump start vehicles unless the unit
has a battery charging feature designed for this purpose.
03. EMF Information
Electric current flowing through any conductor causes localized electric and magnetic fields
(EMF). The current from arc welding (and allied processes including spot welding, gouging,
plasma arc cutting, and induction heating operations) creates an EMF field around the welding
circuit. EMF fields may interfere with some medical implants, e.g. pacemakers. Protective
measures for persons wearing medical implants have to be taken. For example, restrict access
for passers−by or conduct individual risk assessment for welders. All welders should use the
following procedures in order to minimize exposure to EMF fields from the welding circuit:
1. Keep cables close together by twisting or taping them, or using a cable cover.
2. Do not place your body between welding cables. Arrange cables to one side and away
from the operator.
3. Do not coil or drape cables around your body.
4. Keep head and trunk as far away from the equipment in the welding circuit as possible.
5. Connect work clamp to workpiece as close to the weld as possible.
6. Do not work next to, sit or lean on the welding power source.
7. Do not weld whilst carrying the welding power source or wire feeder.
About Implanted Medical Devices:
Implanted Medical Device wearers should consult their doctor and the device manufacturer before performing or going near arc welding, spot welding, gouging, plasma arc cutting, or
induction heating operations. If cleared by your doctor, then following the above procedures is
recommended.
54
Safety Quick-Guide
4. Special Situations & Equipment
Confined spaces can be hazardous.
Confined spaces are areas which lack room for full movement and often lack ventilation, such
as storage tanks, vats, tunnels, boilers, pipes, hold of a ship, corners of a room, near a ceiling
or floor corner, or in a pit. Gases can collect and form dangerous concentrations.
Always open all covers, remove any hazardous or toxic materials, provide forced ventilation,
and provide a means to turn off power and gas from the inside.
Never work alone — have constant communication with someone outside who can quickly
turn off power and gas, is trained in rescue procedures, and is able to pull you out in case
of emergency.
Do not use AC weld output in confined spaces.
Insulate yourself from work and ground using non-flammable, dry insulating material if
possible, or use dry rubber mats, dry wood or plywood, or other dry insulating material big
enough to cover your full area of contact with the work or ground, and watch for fire.
Always check and monitor the air quality in the space. Welding or cutting fumes and gases
can displace air and lower the oxygen level — use ventilation and, if needed, an air-supplied
respirator. Be sure the breathing air is safe. The recommended way to determine adequate
ventilation is to sample for the composition and quantity of fumes and gases to which
personnel are exposed.
Always remember: All normal arc welding and cutting hazards are amplified in confined
spaces (see ANSI Z49.1 listed in Section 9).
Cylinders can explode if damaged.
Compressed gas cylinders contain gas under high pressure. If damaged, a cylinder can
explode. Since gas cylinders are normally part of the welding process and may be part of the
cutting process, be sure to treat them carefully.
Protect compressed gas cylinders from excessive heat, mechanical shocks, slag, open
flames, sparks, and arcs.
Install cylinders in an upright position by securing them to a stationary support or cylinder rack
to prevent falling or tipping.
Keep protective cap in place over valve except when cylinder is in use or connected for use.
Turn face away from valve outlet when opening cylinder valve. Do not stand in front of or
behind the regulator when opening the valve.
Cylinders can be heavy — use lifting device and proper methods to prevent back injury.
Read and follow instructions on compressed gas cylinders, associated equipment, and CGA
publication P-1 listed in Safety Standards (see Section 9).
Electric and magnetic fields (EMF) can affect
Implanted Medical Devices.
Wearers of Pacemakers and other Implanted Medical Devices should keep away.
Implanted Medical Device wearers should consult their doctor and the device manufacturer
before going near arc welding, spot welding, gouging, plasma arc cutting, or induction heating
operations.
55
Safety Quick-Guide
Chock wheels when trailer is uncoupled from vehicle.
1. Chock in direction of grade.
2. Position chock snugly behind tire.
3. Place chock square to the tire.
4. Tap chock into place.
5. For added protection, chock both sides
of tire.
Lights that are not working can cause accidents.
Tail, Stop, and
Turn Lights
Be sure vehicle and trailer light connectors match and are securely pushed
together.
Check all lights for proper operation
before using the trailer.
Check condition of wiring harness
leads, plugs, bulbs, and connections
regularly. Repair or replace damaged
bulbs, parts, or wires.
Side Marker Lights
Unexpected tilting of trailer can injure, and damage equipment.
When trailer is uncoupled from towing
vehicle, use jack on front and blocks
under rear to prevent tilting.
Use proper blocks that are large
enough and able to support the necessary weight.
Always chock the wheels when uncoupled.
Loose or incorrect hardware and fasteners can injure, and
damage equipment.
Periodically double-check all nuts and
bolts for tightness and condition.
Grade Marks
Manufacturer’s
Identification Mark
56
If necessary, always replace any
fastener with one of equal size, grade,
and type.
Be sure the grade marks on replacement fastener match the original bolt.
The manufacturer’s identification mark
is not critical and does not matter for the
replacement fastener.
Safety Quick-Guide
Incorrect tongue weight can cause fishtailing and loss of control of
towing vehicle resulting in injury and equipment damage.
Install generator according to Owner’s Manual with engine end toward
hitch end of trailer.
Tongue − Level
Ground generator frame to trailer
frame — see Owner’s Manual.
Bathroom
Scale
Distribute weight so that trailer
tongue weight is approximately 10%
of the gross trailer weight (GTW).
Pipe
Approximately
10% Of GTW
Board
Trailer
And
Coupler
Class1
Gross Vehicle
Weight Rating
GVWR
lb (kg)
Gross Trailer
Weight GTW2
lb (kg)
Maximum
Tongue Weight3
lb (kg)
1
Up to 2000
(Up to 910)
1000 (455)
2000 (910)
100 (45)
200 (90)
2
2000 to 3500
(910 to 1590)
2000 (910)
3500 (1590)
200 (90)
350 (158)
3
3500 to 5000
(1590 to 2270)
3500 (1590)
350 (158)
Do not let tongue weight exceed
coupler and hitch rating.
1
Information From SAE J684 July 2005
2
Gross Trailer Weight (Actual Loaded Weight)
3
10% Of GTW Recommended
Safety chains can prevent runaway trailer in case hitch/coupler
fails.
Always use safety chains when
towing.
Bottom View
Cross safety chains under coupling to
prevent tongue from dropping to
ground.
Allow only enough slack for tight
turns.
Side View
Incorrect size or rating of hitch can cause trailer to break loose
from towing vehicle.
Make sure hitch and ball are properly
sized, match each other, and are
fully engaged.
Couplers
On optional ball couplers, always
insert hitch safety pin before towing.
Clevis
Trailer
Tongue
Lunette
Eye
Ball
Safety Pin
57
Safety Quick-Guide
Arc rays can burn eyes and skin.
Use welding helmet or face shield with correct shade of filter (see
Section 10 to choose the correct shade).
Wear welders cap and safety glasses with side shields. Use ear
protection when cutting out of position or in confined spaces.
Button shirt collar.
Wear body protection made from durable, flame-resistant material
(leather, heavy cotton, wool). Body protection includes oil-free
clothing such as leather gloves, heavy shirt, cuffless trousers, high
shoes, and a cap.
05.
Trailer Safety
Overloading can injure, and damage equipment.
Know the capacity of the trailer.
Rating
Plate
Do not overload the trailer.
Select a proper towing vehicle.
GVWR − Gross Vehicle Weight Rating
(Maximum Total Trailer Weight Including Its Load)
GAWR − Gross Axle Weight Rating
VIN NO − Vehicle Identification Number
58
Safety Quick-Guide
Electric shock from torch or wiring can kill.
Wear dry insulating gloves. Do not wear wet or damaged gloves.
Do not touch live electrical parts.
Do not use worn, damaged, undersized, or repaired cables.
Protect yourself from electric shock by insulating yourself from
work and ground. Use non-flammable, dry insulating material if
possible, or use dry rubber mats, dry wood or plywood, or other dry
insulating material big enough to cover your full area of contact
with the work or ground, and watch for fire.
Disconnect input plug or power before working on machine.
Do not make input connections if color blind.
Frequently inspect input power cord and ground conductor for
damage or bare wiring – replace immediately if damaged – bare
wiring can kill. Keep cords dry, free of oil and grease, and protected
from hot metal and sparks. Be sure input ground wire is properly
connected to a ground terminal in disconnect box or receptacle.
Properly install, ground, and operate this equipment according to
its Owner’s Manual and national, state, and local codes.
Breathing cutting fumes can be hazardous to
your health.
Keep your head out of the fumes. Do not breathe the fumes. Use
enough ventilation, exhaust at the arc, or both, to keep fumes and
gases from your breathing zone and the general area. The
recommended way to determine adequate ventilation is to sample
for the composition and quantity of fumes and gases to which
personnel are exposed.
Read and understand the Safety Data Sheets (SDSs) and the
manufacturer’s instructions for adhesives, coatings, cleaners,
consumables, coolants, degreasers, fluxes, and metals.
Use enough forced ventilation or local exhaust (forced suction) at
the arc to remove the fumes from your breathing area.
Use a ventilating fan to remove fumes from the breathing zone and
cutting area.
If adequacy of ventilation or exhaust is uncertain, have your
exposure measured and compared to the Threshold Limit Values
(TLV) in the Safety Data Sheet (SDS).
59
Safety Quick-Guide
06. Plasma Arc Cutting Hazards
Cutting sparks can cause fire or explosion.
Do not cut near flammable material or where the atmosphere may
contain flammable dust, gas, or liquid vapors (such as gasoline)..
Move flammables at least 35 feet (11 meters) away or protect them
with flame-proof covers (see NFPA 51B listed in Section 9).
Cutting sparks can cause fires. Have a fire extinguisher nearby,
and have a trained fire watch ready to use it. After completion of
work, inspect area to ensure it is free of sparks, glowing embers,
and flames.
Do not cut on containers that have held combustibles, or on closed
containers such as tanks, drums, or pipes unless they are properly
prepared according to AWS F4.1 and AWS A6.0 (see Safety
Standards in Section 9).
Plasma arc can injure.
Turn off power before disassembling torch.
Do not grip material near cutting path.
Do not touch hot parts bare-handed.
60
Safety Quick-Guide
Using a generator indoors CAN KILL YOU IN
MINUTES.
Generator exhaust contains carbon monoxide. This is a poison you cannot see or smell.
NEVER use inside a home or garage, EVEN IF doors and windows are open.
Only use OUTSIDE and far away from windows, doors, and vents.
Moving parts can injure.
Keep hands, hair, loose clothing, and tools away from moving parts such as fans, belts, and
rotors. Keep all doors, panels, and guards closed and secured.
Battery explosion can injure.
Sparks can cause battery gases to explode.
Do not smoke and keep matches and flames away from battery.
Wear a face shield or safety glasses when working near or on a battery.
Battery acid can burn skin and eyes.
Do not spill acid.
Wear rubber gloves and a face shield or safety glasses when working on a battery.
Steam and hot coolant can burn.
Check coolant level when engine is cold to avoid scalding.
If the engine is warm and checking is needed, wear safety glasses and gloves and put a rag
over radiator cap. Turn cap slightly and let pressure escape slowly before completely
removing cap.
Exhaust sparks can cause fire.
Use approved engine exhaust spark arrestor in required areas — see applicable codes.
Keep exhaust and exhaust pipes away from flammables.
Do not locate unit near flammables.
61
Safety Quick-Guide
Arc rays can burn eyes and skin.
Use welding helmet with correct shade of filter (see Section 10 to
choose the correct shade).
Wear welders cap and safety glasses with side shields. Use ear
protection when welding out of position or in confined spaces.
Button shirt collar.
Wear body protection made from durable, flame-resistant material
(leather, heavy cotton, wool). Body protection includes oil-free
clothing such as leather gloves, heavy shirt, cuffless trousers, high
shoes, and a cap.
07.
Engine Hazards
Fuel can cause fire or explosion.
Engine fuel plus flames or sparks can cause fire or explosion.
+ =
Do not weld near engine fuel.
Do not spill fuel. If fuel is spilled, clean it up and do not start engine
until fumes are gone.
Do not smoke while fueling or if near fuel or fumes.
Stop engine before fueling.
Do not fuel a hot engine. Stop engine and let it cool off before
checking or adding fuel.
62
Safety Quick-Guide
Breathing welding fumes can be hazardous to
your health.
Keep your head out of the fumes. Do not breathe the fumes. Use
enough ventilation, exhaust at the arc, or both, to keep fumes and
gases from your breathing zone and the general area. The
recommended way to determine adequate ventilation is to sample
for the composition and quantity of fumes and gases to which
personnel are exposed.
Read and understand the Safety Data Sheets (SDSs) and the
manufacturer’s instructions for adhesives, coatings, cleaners,
consumables, coolants, degreasers, fluxes, and metals.
Use enough forced ventilation or local exhaust (forced suction) at
the arc to remove the fumes from your breathing area.
Use a ventilating fan to remove fumes from the breathing zone and
welding area.
If adequacy of ventilation or exhaust is uncertain, have your
exposure measured and compared to the Threshold Limit Values
(TLV) in the Safety Data Sheet (SDS).
Welding can cause fire or explosion.
Do not weld near flammable material or where the atmosphere
may contain flammable dust, gas, or liquid vapors (such as
gasoline). Move flammables at least 35 feet (11 meters) away or
protect them with flame-proof covers (see NFPA 51B listed in
Section 9).
Welding sparks can cause fires. Have a fire extinguisher nearby,
and have a trained fire watcher ready to use it. After completion of
work, inspect area to ensure it is free of sparks, glowing embers,
and flames.
Do not weld on containers that have held combustibles, or on
closed containers such as tanks, drums, or pipes unless they are
properly prepared according to AWS F4.1 and AWS A6.0 (see
Safety Standards in Section 9).
63
Safety Quick-Guide
08. General Safe Practices
Become trained and read the instructions before working on the machine
or welding or cutting. Read and understand the Safety Data Sheets
(SDSs) and the manufacturer’s instructions for adhesives, coatings,
cleaners, consumables, coolants, degreasers, fluxes, and metals.
+
Wear approved safety glasses with side shields under your welding
helmet or face shield and at all times in the work area.
Read and follow all labels and the Owner’s Manual carefully before
installing, operating, or servicing unit. Read the safety information at
the beginning of the manual and in each section.
Wear a safety harness if working above floor level.
Keep children away from all equipment and processes.
Do not install or place machine on or over combustible surfaces.
Use GFCI protection when operating auxiliary equipment in damp or
wet locations.
Use only genuine replacement parts from the manufacturer.
Perform maintenance and service according to the Owner’s
Manuals, industry standards, and national, state, and local codes.
09. Arc Welding Hazards
Electric shock from welding electrode or wiring
can kill.
Wear dry, hole-free insulating gloves and body protection. Do not
touch electrode with bare hand. Do not wear wet or damaged gloves.
Do not touch live electrical parts.
Do not use AC weld output in damp, wet, or confined spaces, or if
their is a danger of falling.
Use AC output ONLY if required for the welding process.
If AC output is required, use remote output control if present on unit.
Do not use worn, damaged, undersized, or repaired cables,
Protect yourself from electric shock by insulating yourself from work
and ground. Use non-flammable, dry insulating material if possible,
or use dry rubber mats, dry wood or plywood, or other dry insulating
material big enough to cover your full area of contact with the work
or ground, and watch for fire.
Disconnect input plug or power before working on machine.
Do not make input connections if color blind.
Frequently inspect input power cord and ground conductor for
damage or bare wiring – replace immediately if damaged – bare
wiring can kill. Keep cords dry, free of oil and grease, and protected
from hot metal and sparks. Be sure input ground wire is properly
connected to a ground terminal in disconnect box or receptacle.
Properly install, ground, and operate all equipment according to its
Owner’s Manual and national, state, and local codes.
64
ADVICE
THINK
SAFE
FOLLOW SAFETY
65
SAFETY AND HEALTH OF WELDERS
66
Illustrations
1. Precautionary Information for Arc Processes and Equipment
2. Page 1 of Typical Material Safety Data Sheet
3. Page 2 of Typical Material Safety Data Sheet
4. Page 3 of Typical Material Safety Data Sheet
5. Welder Dressed for Light Duty Welding
6. Welder Dressed for Heavy Duty Welding
7. Precautionary Information for Oxyfuel Gas Processes
8. Insulating Devices on Terminals of a Welding Machine
9. Welding Helmet
10. Eye Protection Filter Shade Selector
11. Welding Station Using Transparent Welding Screen
12. Precautionary Information for Fluxes That Contain Fluorides
13. Precautionary Information for Brazing Filler Metals Containing
Cadmium.
14. Welding Booths With Mechanical Ventilation
15. Local Exhaust Ventilation Using Movable Hood
16. Local Exhaust Ventilation Using Welding Gun Exhaust Nozzle
17. Local Exhaust Ventilation Comparison With and Without Exhaust
18. Local Exhaust Ventilation Using Movable Hood Design
19. Hot Work Permit
20. Safe Way To Weld Containers That Held Combustibles
21. Worker Wearing Suitable Ear Protection for Noisy Work
67
WARNING:
1. Personal Protection and
Safety Rules
PROTECT yourself and others. Read and understand this information.
FUMES AND GASES can be hazardous to your health.
ARC RAYS can injure eyes and burn skin.
Your safety and health is extremely important. All workers engaged in production and construction are continually exposed to
potential hazards. There are a number of potential safety and health
problems associated with welding, cutting, and allied processes.
When correct precautionary measures are followed, welding is a
safe occupation. Health officials state that welding, as an occupation, is no more hazardous or injurious to the health than other
metal working occupations.(l)
ELECTRIC SHOCK can KILL.
• Before use, read and understand the manufacturer’s instructions, Material Safety Data
Sheets (MSDSs) and your employer’s safety practices.
• Keep your head out of the fumes.
• Use enough ventilation, exhaust at the arc, or both, to keep fumes and gases from
your breathing zone and the general area.
• Wear correct eye, ear, and body protection.
• Do not touch live electrical parts.
Governments have become increasingly active concerning the
safety and health of workers and have enacted laws prescribing
safety regulations and the publication of safety information to
insure the safety of workers. In the United States, the provisions
of the Occupational Safety and Health Act (OSHA)(2) are the law. It
makes many national consensus standards enforceable. The most
important welding standard is the American National Standard
“ANSI Z49.1, Safety in Welding,Cutting, and Allied Processes”.
• See American national Standard ANSI Z49.1: Safety in Welding, Cutting, and Allied
Processes, published by the American Welding Society, 550 N. W. LeJeune Road,
Miami, FL 33126; OSHA Safety and Health Standards are published by the U.S.
Government Printing Office, 732 North Capitol Street NW, Washington, DC 20401.
DO NOT REMOVE THIS INFORMATION
Figure 1 - Precautionary Information for Arc Welding
Processes and Equipment
(3)
This standard states that welding and cutting operations pose
potential hazards from fumes, gases, electric shock, heat radiation, and sometimes noise. All personnel shall be warned against
these hazards where applicable by the use of adequate precautionary labeling. The minimum precautionary label for arc welding
processes and equipment, which is recommended, is shown in
Figure 1. There are other hazards which apply to all metal working
occupations. These are accidents resulting from falling, being hit
by moving objects, working around moving machinery, exposure
to hot metal, etc. Normal precautions are required with regard to
these hazards as well. Hazards that relate to welding are:
Electrical shock
Arc radiation
Compressed gases
Welding cleaning
Air contamination
Fire and explosion
Other hazards related to
specific occupations
such as the proper fire extinguishers, life saving and support
equipment, first aid kits, and so on. Train personnel to utilize this
equipment properly. Only approved equipment should be used and
it must be properly installed and maintained in good working order.
Material Safety Data Sheets (MSDSs)
OSHA requires that employers must have a comprehensive hazard communication program to inform employees about hazardous
substances that might be used in the workplace. The purpose of
the MSDSs is to explain the hazards involved in handling/using
products such as welding consumables and the precautionary
measures which must be put in place for safe welding. The employer must maintain continuous training concerning such materials, and safety in general. Provisions to safeguard employees are
included in Material Safety Data Sheets (MSDSs) as prescribed
by the Hazard Communication Standard of the U.S. Department
Welders work under a variety of conditions including outdoors,
indoors, in open areas, in confined spaces, high above the ground,
and even under water. They utilize a large number of welding and
of Labor.(5) Information must be provided for all substances taken
into the workplace except foods, drugs, cosmetics or tobacco
products used for personal consumption. The use of these data
sheets in all manufacturing workplaces has been mandated since
1985. Employees must be trained on the information in Material
Safety Data Sheets and labels.
cutting processes, however most of these have in common the
exposure to fumes, gases, radiation and heat. Welders may be
exposed to a number of factors simultaneously. The use of specific
welding processes or welding on particular metals can present
potential health risks, which will be covered later. Additional information is available in the American Welding Society publications
listed in the references section of this book.
Each Material Safety Data Sheet for welding products includes
information about every hazardous component comprising 1% or
more of the contents, and for every potential carcinogen (cancer
inciting or producing) comprising 0.1% or more. Many of the components are included in the listing by the American Conference of
Governmental Industrial Hygienists with threshold limit values.(6)
Welding Workplace Safety
The welding management and supervisors are responsible for
assuring the workers are trained in the safe conduct of their day
to day activities. Employees must be informed and trained so
that they are able to detect when hazards are present and protect
themselves from them.
Material Safety Data Sheets are required to be provided automatically by the suppliers of welding electrodes, fluxes, and
gases. They should be kept on file in the personnel or welding
departments and be readily available in the workplace. The training
program must cover not only welders, but others working in the
welding area such as service personnel, maintenance personnel,
regular visitors to the welding shop, and others. A typical material
safety data sheet for a tubular arc welding electrode is shown in
Figures 2, 3, and 4. Particular points of interest are highlighted to
provide more data for intelligent interpretation of this information.(7)
Hazardous communication programs and welding safety training
programs must be ongoing.
The welders and other employees have an obligation to learn
and use safe practices and to obey safety rules and regulations.
They are responsible for the proper use of equipment. They have
an obligation to learn safe practices, to obey safety rules and
regulations and are expected to work in a safe manner. It is the
responsibility of supervisors to assure safety rules and regulations
are followed.
Combustible materials must not be allowed to collect in or near
the welding workplace. Good housekeeping practices should
always be employed. Adequate safety devices should be provided
68
MSDS NO: TR-TW
REVISED: (date)
TW 2885
MATERIAL SAFETY DATA SHEET
For U.S. Manufactured or Distributed Welding Consumables and Related Products. May be used to comply with OSHA’s Hazard Communication Standard,
29 CFR 1910. 1200 and Superfund Amendments and Reauthorization Act (SARA) of 1986 Public Law 99-499. Standard must be consulted for specific requirements.
Hazards in
the filler
metal or
flux itself
SECTION 1 – IDENTIFICATION
Manufacturer/Supplier Name:
ABC COMPANY
Address:
MAIN STREET, ANY CITY, ZIPCODE, USA
Telephone No: (000) 000-0000
Emergency No: (000) 000-0000
Products For: TUBULAR ARC WELDING ELECTRODES FOR FLUX CORED, METAL CORED AND COMPOSITE SUBMERGED ARC WELDING “GROUP A”: Product
Type: Gas Shielded Carbon and Low Alloy Steel“GROUP B”: Product Type: Self-Shielded Carbon Steel
“GROUP C”: Product Type: Carbon and Low Alloy Steel “GROUP D”: Product Type: Corrosion Resisting Steel Metal Cored
Ch e mical
Abstracts
Service No.
(safety information,
immediately available
by telephone to
physicians
and paramedics).
PEL=
Permissible
E xpo sur e
Limit, mg/
m3.
American
Conference
of Governmental
Industrial
Hygienists
Threshhold Limit
Value (mg/
m3). Timeweighted
average.
SECTION 2 - HAZARDOUS INGREDIENTS
IMPORTANT - This section covers the hazardous materials from which this product is manufactured. The fumes and gases produced during welding
with normal use of this product are also addressed in Section 5. The term “hazardous” in this section should be interpreted as a term required and
defined in OSHA Hazard Communication Standard (29 CFR Part 1910.1200).
Group D
75-95
—
<2
CAS NO.
7439-89-6
1309-37-1
7439-96-5
EXPOSURE LIMIT (mg/m3)
OSHA PEL
ACGIH TLV
5 R*
3 R*
10 (Oxide Fume)
5 R*(Oxide {A4}
5
CL**
(Fume)
<10
<4
<5
<2
<2
<2
—<2
13463-67-7
7440-21-3
7789-75-5
7439-98-7
1, 3 STEL*** (Fume)
15 (Dust)
5 R*
2.5 (as F)
5 R*
<2(7)
—
—
1317-65-3
<2
<5(6)
<3(6)
—
7429-90-5
MAGNESIUM+
MAGNESIUM OXIDE
BARIUM FLOURIDE#
NICKEL#
—
—
—
—
<3
<3
5-15(1)
—
—
—
5-15(3)
<4
—
—
—
<1
7439-95-4
1309-48-4
7787-32-8
7440-02-0
5 R*
15 (Fume, total particulate)
0.5 (as Ba)
1 (Metal)
1 (Soluble Compounds)
1 (Insoluble Compounds)
CHROMIUM#
—-
—
<3
5 - 20
7440-47-3
1 (Metal)
0.5 (Cr II & Cr III Compounds)
0.005 (Cr VI Compounds)
COPPER#
<1(2)
—
<2(2)
—
7440-50-8
TITANIUM+
SILICA++
(Amorphous Silica Fume)
LITHIUM FLUORIDE
STRONTIUM FLUORIDE
COBALT
CERIUM OXIDE
—
<2
—
—
<2
<2
<2
—
—
—
——-
<2(9)
<2(8)
——-
<2(9)
—
—
—
——
7440-32-6
14808-60-7
69012-64-2
7789-24-4
7783-48-4
7440-48-4
1306-38-3
1 (Dust)
0.1 (Fume)
5 R*
0.1 R*
0.8
2.5 (as F)
2.5 (as F)
0.1 (Dust&Fume)
15 (Dust)
5 R* (Dust)
HAZARDOUS%
INGREDIENTS
IRON+
IRON OXIDE
MANGANESE#
WEIGHT
Group A Group B
75-98
75-95
—
—
<4.5
<2
0.2
TITANIUM DIOXIDE
SILICON+
FLUORSPAR
MOLYBDENUM
<10
<4
<5(5)
<1
<4(4)
<2(4)
1-10
—
CALCIUM CARBONATE
<2
ALUMINUM###
Group C
75-95
<2
<4
<1(10)
<2(11)
5 R*
5 (as CaO)
5 R* (Dust)
(As inorganic Compounds of Mn)
10 {A4}
3 R* u u u
2.5 (as F) {A4}
3 R*; 10 I*
(Elemental and Insoluble)
0.5 R*(Soluble Compounds) {A3}
10 u u u u u
2 (as CaO)
10 (Dust)
2 (soluble salts, as Al)
3 R*
10 I* {A4}
0.5 (as Ba) {A4}
1.5 I* (Elemental) {A5}
0.1 I* (Soluble Compounds) {A4}
0.2 I* (Insoluble Compounds)
{A1}
0.5 (Metal) {A4}
0.5 (Cr III Compounds) {A4}
0.05 (Cr VI Soluble Compounds)
{A1}
0.01 (Cr VI Insoluble
Compounds) {A1}
1 (Dust and Mists)u, u u
0.2 (Fume)u, u u
3 R*
0.025 R* {A2}
3 R* u u u
2.5 (as F) {A4}
2.5 (as F) {A4}
0.02 {A3}
10 (Dust)
3 R* (Dust)
(1) Present only in Group B Product Types (2) Present only in Group A and Group C Product Types (3) Present only in Group C Product Types (4) Present only in Group B
Product Types (5) Present only in Group A Product Types (6) Present in All Group B Product Types (7) Present only in Group C Product Types (8) Present only in Group B
Product Types (9) Present only in Group C Product Types (10) Present only in Group C Product Types (11) Present only in Group C Product Types
* - Respirable Fraction I* - Inhalable Fraction ** - Ceiling Limit *** - Short Term Exposure Limit. + - As a nuisance particulate covered under “Particulates Not Otherwise
Regulated” by OSHA or “Particulates Not Otherwise Classified” by ACGIH. ++ - Crystalline silica is bound within the product as it exists in the package. However, research indicates
silica is present in welding fume in the amorphous #- Reportable material under Section 313 of SARA. ### - Reportable material under Section 313 of SARA as dust or fume. {A1}
- Confirmed Human Carcinogen per ACGIH {A2} - Suspected Human Carcinogen per ACGIH {A3} - Confirmed Animal Carcinogen with Unknown Relevance to Humans per
ACGIH {A4} - Not Classifiable as a Human Carcinogen per ACGIH {A5} - Not Suspected as a Human Carcinogen per ACGIH (noncrystalline) form. u - Listed under Notice of
Intended Changes in 2006 per ACGIH uu - Limit of 0.1 mg/m3 is proposed for Cu I* and 0.05 mg/m3 is proposed for Cu R* of soluble compounds in 2006 by ACGIH uuu - TLV
withdrawn in 2006 uuuuu - Intention to withdraw TLV in 2006 per ACGIH
The exposure limit for welding fume has been established at 5 mg/m3 with OSHA’s PEL and ACGIH’s TLV. The individual complex compounds within the fume may have
lower exposure limits than the general welding fume PEL/TLV. An Industrial Hygienist, the OSHA Permissible Exposure Limits For Air Contaminants (29 CFR 1910.1000),
and the ACGIH Threshold Limit Values should be consulted to determine the specific fume constituents present and their respective exposure limits.
Figure 2 - Page 1 of 3 of Typical Material Safety Data Sheet
69
SECTION 3 - PHYSICAL/CHEMICAL CHARACTERISTICS
Welding consumables applicable to this sheet are solid and nonvolatile as shipped.
SECTION 4 - FIRE AND EXPLOSION HAZARD DATA
Welding consumables applicable to this sheet as shipped are nonreactive, nonflammable, nonexplosive and essentially nonhazardous until welded.
Welding arcs and sparks can ignite combustibles and flammable products. See American National Standard Z49.1 referenced in Section 7.
Hazards created
by the welding arc
or torch.
Typical fumes.
Gases
How to sample
actual fumes.
Note effects of
overexposure.
SECTION 5 - REACTIVITY DATA - HAZARDOUS DECOMPOSITION PRODUCTS
Welding fumes and gases cannot be classified simply. The composition and quantity of both are dependent upon the metal being welded, the process,
procedures and electrodes used. Most fume ingredients are present as complex oxides and compounds and not as pure metals.
Other conditions which also influence the composition and quantity of the fumes and gases to which workers may be exposed include: coatings
on the metal being welded (such as paint, plating or galvanizing), the number of welders and the volume of the work area, the quality and amount
of ventilation, the position of the welder’s head with respect to the fume plume, as well as the presence of contaminants in the atmosphere (such as
chlorinated hydrocarbon vapors from cleaning and degreasing activities).
When the electrode is consumed, the fume and gas decomposition products generated are different in percent and form from the ingredients listed in
Section 2. Decomposition products of normal operation include those originating from the volatilization, reaction or oxidation of the materials shown
in Section 2, plus those from the base metal and coating, etc., as noted above.
Reasonably expected constituents of the fume would include: Complex oxides of iron, manganese, silicon and titanium. Groups A and B may also
contain calcium oxides. Groups A, B and C may have fluorides present. Groups A, C, and D may also contain molybdenum. Group B may also
contain magnesium. Groups A, B, and C may also contain aluminum. Groups B and C may also contain barium. Groups A and C may also contain
copper. Groups C and D may also contain chromium and nickel. Group B may also contain magnesium, lithium and strontium.
Monitor for the materials identified in Section 2. Fumes from the use of this product may contain barium, fluorides, manganese, calcium
oxide, chromium and nickel compounds, copper, and amorphous silica fume whose exposure limits are lower than the 5 mg/m3 PEL/TLV for
general welding fume.
Gaseous reaction products may include carbon monoxide and carbon dioxide. Ozone and nitrogen oxides may be formed by the radiation from the arc.
One recommended way to determine the composition and quantity of fumes and gases to which workers are exposed is to take an air sample inside
the welder’s helmet if worn or in the worker’s breathing zone. [See ANSI/AWS F1.1, available from the “American Welding Society”, P.O. Box
351040, Miami, FL 33135. Also, from AWS is F1.3 “Evaluating Contaminants in the Welding Environment - A Sampling Strategy Guide”, which
gives additional advice on sampling.]
SECTION 6 - HEALTH HAZARD DATA
EFFECTS OF OVEREXPOSURE:
Electric arc welding may create one or more of the following health hazards:
ARC RAYS can injure eyes and burn skin.
ELECTRIC SHOCK can kill. See Section 7.
FUMES AND GASES can be dangerous to your health.
PRIMARY ROUTES OF ENTRY are the respiratory system, eyes and/or skin.
SHORT-TERM (ACUTE) OVEREXPOSURE EFFECTS:
WELDING FUMES - May result in discomfort such as dizziness, nausea or dryness or irritation of nose, throat or eyes.
IRON, IRON OXIDE - None are known. Treat as nuisance dust or fume.
MANGANESE - Metal fume fever characterized by chills, fever, upset stomach, vomiting, irritation of the throat and aching of body. Recovery is
generally complete within 48 hours of the overexposure.
TITANIUM DIOXIDE - Irritation of respiratory system.
SILICA (AMORPHOUS) - Dust and fumes may cause irritation of the respiratory system, skin and eyes.
FLUORIDES - Fluoride compounds evolved may cause skin and eye burns, pulmonary edema and bronchitis.
MOLYBDENUM, CERIUM OXIDE - Irritation of the eyes, nose and throat.
CALCIUM OXIDE - Dust or fumes may cause irritation of the respiratory system, skin and eyes.
ALUMINUM OXIDE - Irritation of the respiratory system.
MAGNESIUM, MAGNESIUM OXIDE - Overexposure to the oxide may cause metal fume fever characterized by metallic taste, tightness of chest
and fever. Symptoms may last 24 to 48 hours following overexposure.
BARIUM - Aching eyes, rhinitis, frontal headache, wheezing, laryngeal spasms, salivation or anorexia.
NICKEL, NICKEL COMPOUNDS - Metallic taste, nausea, tightness in chest, metal fume fever, allergic reaction.
CHROMIUM - Inhalation of fume with chromium (VI) compounds can cause irritation of the respiratory tract, lung damage and asthma-like symptoms.
Swallowing chromium (VI) salts can cause severe injury or death. Dust on skin can form ulcers. Eyes may be burned by chromium (VI) compounds.
Allergic reactions may occur in some people.
COPPER - Metal fume fever characterized by metallic taste, tightness of chest and fever. Symptoms may last 24 to 48 hours following overexposure.
STRONTIUM COMPOUNDS - Strontium salts are generally non-toxic and are normally present in the human body. In large oral doses, they may
cause gastrointestinal disorders, vomiting and diarrhea.
LITHIUM COMPOUNDS - Overexposure may cause tremor and
nausea. COBALT – Pulmonary irritation, cough, dermatitis, weight loss.
LONG-TERM (CHRONIC) OVEREXPOSURE EFFECTS:
WELDING FUMES - Excess levels may cause bronchial asthma, lung fibrosis, pneumoconiosis or “siderosis.”
IRON, IRON OXIDE FUMES - Can cause siderosis (deposits of iron in lungs) which some researchers believe may affect pulmonary function. Lungs
will clear in time when exposure to iron and its compounds ceases. Iron and magnetite (Fe3O4) are not regarded as fibrogenic materials.
MANGANESE - Long-term overexposure to manganese compounds may affect the central nervous system. Symptoms may be similar to Parkinson’s
Disease and can include slowness, changes in handwriting, gait impairment, muscle spasms and cramps and less commonly, tremor and behavioral
changes. Employees who are overexposed to manganese compounds should be seen by a physician for early detection of neurologic problems.
TITANIUM DIOXIDE - Pulmonary irritation and slight fibrosis.
SILICA (AMORPHOUS) - Research indicates that silica is present in welding fume in the amorphous form. Long term overexposure may cause
pneumoconiosis. Noncrystalline forms of silica (amorphous silica) are considered to have little fibrotic potential.
FLUORIDES - Serious bone erosion (Osteoporosis) and mottling of teeth.
MOLYBDENUM - Prolonged overexposure may result in loss of appetite, weight loss, loss of muscle coordination, difficulty in breathing and anemia.
CALCIUM OXIDE - Prolonged overexposure may cause ulceration of the skin and perforation of the nasal septum, dermatitis and pneumonia.
Figure 3 - Page 2 of 3 of Typical Material Safety Data Sheet (see previous page)
70
Apply First Aid.
Beware! Carcinogenic means it may
produce cancer.
ALUMINUM OXIDE - Pulmonary fibrosis and emphysema.
MAGNESIUM, MAGNESIUM OXIDE - No adverse long term health effects have been reported in the literature.
BARIUM - Long term overexposure to soluble barium compounds may cause nervous disorders and may have deleterious effects on the heart,
circulatory system and musculature.
NICKEL, NICKEL COMPOUNDS - Lung fibrosis or pneumoconiosis. Studies of nickel refinery workers indicated a higher incidence of lung
and nasal cancers.
CHROMIUM - Ulceration and perforation of nasal septum. Respiratory irritation may occur with symptoms resembling asthma. Studies
have shown that chromate production workers exposed to hexavalent chromium compounds have an excess of lung cancers. Chromium (VI)
compounds are more readily absorbed through the skin than chromium (III) compounds. Good practice requires the reduction of employee
exposure to chromium (III) and (VI) compounds.
COPPER - Copper poisoning has been reported in the literature from exposure to high levels of copper. Liver damage can occur due to copper
accumulating in the liver characterized by cell destruction and cirrhosis. High levels of copper may cause anemia and jaundice. High levels of
copper may cause central nervous system damage characterized by nerve fiber separation and cerebral degeneration.
STRONTIUM COMPOUNDS - Strontium at high doses is known to concentrate in bone. Major signs of chronic toxicity, which involve the
skeleton, have been labeled as “strontium rickets”.
LITHIUM COMPOUNDS - May be considered as potentially teratogenic.
COBALT – Repeated overexposure to cobalt compounds can produce reduced pulmonary function, diffuse nodular fibrosis of lungs and respiratory
hypersensitivity. IARC considers cobalt compounds as possibly carcinogenic to humans (GROUP 2B).
MEDICAL CONDITIONS AGGRAVATED BY EXPOSURE:
Persons with pre-existing impaired lung functions (asthma-like conditions).
EMERGENCY AND FIRST AID PROCEDURES:
Call for medical aid. Employ first aid techniques recommended by the American Red Cross.
Eyes & Skin: If irritation or flash burns develop after exposure, consult a physician.
CARCINOGENICITY:
Chromium VI and nickel compounds must be considered as carcinogens under OSHA (29 CFR 1910.1200). Chromium VI compounds are
classified as IARC Group 1 and NTP Group 1 carcinogens. Nickel compounds are classified as IARC Group 1 and NTP Group 2 carcinogens.
Welding fumes must be considered as possible carcinogens under OSHA (29 CFR 1910.1200).
CALIFORNIA PROPOSITION 65:
For Group C and D products: WARNING: This product contains or produces a chemical known to the State of California to cause cancer and
birth defects (or other reproductive harm). (California Health & Safety Code Section 25249.5 et seq.)
For Group A and B products: WARNING: This product, when used for welding or cutting, produces fumes or gases which contain chemicals
known to the State of California to cause birth defects and, in some cases, cancer. (California Health & Safety Code Section 25249.5 et seq.)
SECTION 7 - PRECAUTIONS FOR SAFE HANDLING & USE/APPLICABLE CONTROL MEASURES
Ventilate weld
area.
Use r es pir ato r
when necessary.
Wear helmet, filter
lens.
Protect from radiation, sparks electric
shock, hot metal,
sharp edges, pinch
points, falls.
Never exceed permissible exposure
limits.
Protect yourself.
The manufacturer
disclaims any responsibility.
Read and understand the manufacturer’s instructions and the precautionary label on the product. See American National Standard Z49.1; Safety
in Welding and Cutting published by the American Welding Society, P.O. Box 351040, Miami, FL 33135 and OSHA Publication 2206 (29 CFR
1910), U.S. Government Printing Office, Washington, DC 20402 for more detail on any of the following.
VENTILATION: Use enough ventilation, local exhaust at the arc or both to keep the fumes and gases below PEL/TLVs in the worker’s breathing
zone and the general area. Train the welder to keep his head out of the fumes.
RESPIRATORY PROTECTION: Use NIOSH approved or equivalent fume respirator or air supplied respirator when welding in confined
space or where local exhaust or ventilation does not keep exposure below PEL/TLVs.
EYE PROTECTION: Wear helmet or use face shield with filter lens. As a rule of thumb begin with Shade Number 14. Adjust if needed by
selecting the next lighter and/or darker shade number. Provide protective screens and flash goggles, if necessary, to shield others.
PROTECTIVE CLOTHING: Wear hand, head and body protection which help to prevent injury from radiation, sparks and electrical shock.
See ANSI Z49.1. At a minimum this includes welder’s gloves and a protective face shield, and may include arm protectors, aprons, hats, shoulder
protection as well as dark nonsynthetic clothing. Train the welder not to touch live electrical parts and to insulate himself from work and ground.
PROCEDURE FOR CLEANUP OF SPILLS OR LEAKS: Not applicable
WASTE DISPOSAL: Prevent waste from contaminating surrounding environment. Discard any product, residue, disposable container or liner
in an environmentally acceptable manner, in full compliance with Federal, State and Local regulations.
SPECIAL PRECAUTIONS (IMPORTANT): Maintain exposure below the PEL/TLVs. Use industrial hygiene monitoring to ensure that
your use of this material does not create exposures which exceed PEL/TLVs. Always use exhaust ventilation. Refer to the following sources
for important additional information: ANSI Z49.1 from the American Welding Society, P.O. Box 351040, Miami, FL 33135 and OSHA (29 CFR
1910) from the U.S. Department of Labor, Washington, DC 20210.
ABC Company believes this data to be accurate and to reflect qualified expert opinion regarding current research. However, ABC Company
cannot make any expressed or implied warranty as to this information.
Figure 4 - Page 3 of 3 of Typical Material Safety Data Sheet (see previous page)
71
Heat Exposure
In addition to working in hot climates, welders are sometimes
required to weld on, or inside, preheated weldments. The preheat
temperatures required for welding special materials can be quite
high and the welder must be protected from coming into contact
with the hot metal. They should be supplied with sufficient cool air
to avoid breathing excessively hot air. Special precautions must
be taken and special procedures must be adopted to protect the
welder from the heat. Protective clothing should be worn which
helps insulate the welder from excessive heat. Consultation with
safety experts and just plain common sense is required in these
situations.
as quickly. Cloth or soft leather gloves can be used for light-duty
work. For heavy-duty work, more thorough protective clothing is
required. Figure 6 shows a welder dressed for heavy-duty welding
work wearing leather gauntlet gloves, a leather cape, leather bib,
and spats, which give additional protection against sparks and
molten metal. When welding in the vertical and overhead position
this type of clothing is required. In all cases a headcap should be
used. Flame-retardant clothing should be worn. Clothing should
always be kept dry, and this applies to gloves as well. High top
shoes with safety toes are recommended. The leather clothes
should be of the chrome-tanned type or its equivalent. Leather
gloves should not be used to pick up hot items since this will cause
the leather to become stiff and crack. Protective clothing must be
kept in good repair. Check safety equipment regularly for damage.
Replace faulty clothing and equipment. Gloves should be clean,
without holes or tears, and dry. Welding helmets should be checked
for cracks, and filter glasses should be replaced if damaged.
Protective Clothing
Welders should wear work or shop clothes without openings or
gaps to prevent the arc rays from injuring the skin. If the arc rays
contact the skin for a period of time painful “sunburns” or “arc
burns” will result. People working close to arc welding should also
wear protective clothing.
For light-duty welding, normally 200 amperes or lower, the level
of protection can be reduced. Figure 5 shows a welder dressed
for light-duty work. Woolen clothing is more satisfactory than cotton since it will not disintegrate from arc radiation or catch on fire
Signs should be posted in the welding area pointing out precautions that must be taken by employees and visitors. These signs
should be in agreement with Z535 standards(8). The welding area
should also post signs alerting people with heart pace-makers that
they should not enter and to check with their clinician.
Figure 5 - Welder dressed for light duty welding
Figure 6 - Welder dressed for heavy duty welding.
72
Safety Practices
16. Dispose of electrode stubs in proper container since stubs
on the floor are a safety hazard. Hot stubs can ignite fires
or can cause trips and falls.
The following, “Safety Precautions for Arc Welding and Cutting”
and “Safety Precautions for Oxyacetylene Welding and Cutting”
should be read and understood by all welders, cutters, and helpers.
17. Shield others from the light rays produced by your welding
arc. Ultraviolet arc rays can cause “arc flash” to the eyes of
nearby people.
Safety Precautions for Arc Welding and Cutting
1. Make sure your arc welding equipment is installed properly
and grounded and is in good working condition. This will
help prevent fatal electric shocks.
18. Do not weld near degreasing operations. Arc rays can inter-act with fumes of some cleaning agents and produce
hazardous gases. Some of these gases can kill.
2. Always wear protective clothing suitable for the welding to
be done. This will help prevent injuries and burns.
19. When working above ground make sure that scaffold, ladder,
or work surface is solid. Falls from elevated positions can
cause injury or even death.
3. Always wear proper eye protection, when welding, cutting,
or grinding. Do not look at the arc without proper eye protection. This will prevent eye injuries and “arc flash.”
20. When welding in high places, use safety belt or lifeline. Falls
from high places are more likely to cause serious injury or
death.
4. Avoid breathing the air in the fume plume directly above
the arc. This will prevent illness due to overexposure to
hazardous materials in the fume plume.
Safety Precautions for Oxyacetylene Welding and Cutting
1. Make sure that all gas apparatus shows UL or FM approval,
is installed properly and is in good working condition. Make
sure that all connections are tight before lighting the torch. Do
not use a flame to inspect for tight joints. Use soap solution
to detect leaks. This will minimize the chance of fuel gas
leaks. Gas leaks can cause fires and explosions.
5. Keep your work area clean and free of hazards. Make sure
that no flammable, volatile, or explosive materials are in or
near the work area. Good housekeeping will help prevent
accidents.
6. Handle all compressed gas cylinders with extreme care.
Keep caps on when not in use. Damaged cylinders can
rupture with explosive violence.
2. Always wear protective clothing suitable for welding or flame
cutting. This will prevent injuries and burns.
7. Make sure that compressed gas cylinders are secured to
the wall or to other structural supports. The impact of a fall
can cause cylinder rupture or valve failure.
3. Keep work area clean and free from hazardous materials.
When flame cutting sparks can travel up to 35 feet (10.7
m). Do not allow flame cut sparks to hit hoses, regulators,
or cylinders. Good housekeeping will help prevent fires and
explosions.
8. When compressed gas cylinders are empty close the valve
and mark the cylinder “empty”. This will prevent contamination from entering the cylinder.
4. Handle all compressed gas cylinders with extreme care.
Keep cylinder caps on when not in use. Damaged cylinders
can rupture with explosive violence.
9. Do not weld in a confined space without special precautions.
Poor ventilation can lead to asphyxiation. Accumulation of
flammable gases can explode. Always practice “confined
space” safety.
5. Make sure that all compressed gas cylinders are secured
to the wall or to other structural supports. Keep acetylene
cylinders in the vertical position. The impact of a fall can
cause cylinder rupture or valve failure. With horizontal acetylene cyllinders, acetone will be mixed in with the delivered
gas.
10. Do not weld on containers that have held combustibles with
out taking special precautions. The heat of welding can ignite
residual gases and cause an explosion. The heat can cause
the release of hazardous fumes. Always assure a container
is clean and safe for welding.
6. Store compressed gas cylinders in a safe place with good
ventilation. Acetylene cylinders and oxygen cylinders should
be kept apart. This will prevent the accumulation of leaking
gases and possible fires and explosions.
11. Do not weld on sealed containers or compartments without
providing vents and taking special precautions. The heat of
welding can cause gases to expand. The increased pressure can lead to an explosion.
7. When compressed gas cylinders or fuel gas cylinders are
empty, close the valve and mark the cylinder “empty”. This
will prevent contamination from entering the cylinder.
12. Use mechanical exhaust at the point of welding when welding
lead, cadmium, chromium, manganese, brass, bronze, zinc,
or galvanized steel, and when welding in a confined space.
These “low allowable-limit materials” cancause serious injury.
Ventilation will prevent overexposure. (Refer to ref. 3)
8. Use oxygen and acetylene or other fuel gases with the apropriate torches and only for the purpose intended. This will
minimize the chance of sustained backfires and flash-backs.
13. When it is necessary to weld in a damp or wet area, wear
rubber boots and stand on a dry insulated platform. This
will minimize the chance of electric shocks.
9. Avoid breathing the air in the fume plume directly above
the flame. This will prevent illness due to overexposure to
hazardous materials in the fume plume.
14. Do not use cables with frayed, cracked, or bare spots in the
insulation. This will prevent stray arcs between the bare
cable and the ground. It will prevent electric shocks.
10. Never use acetylene at a pressure in excess of 15 psi (103.4k
Pa). Higher pressure can cause an explosion. The high
pressure can cause acetylene to detonate spontaneously.
15. When the electrode holder is not in use, hang it on brackets
provided. Never let it touch a compressed gas cylinder. This
will help prevent damage to the holder. An energized holder
can arc to a grounded cylinder and cause an explosion.
11.
73
Never use oil, grease or any material on any apparatus or
threaded fittings in the oxyacetylene or oxyfuel system. Oil
and grease in contact with oxygen may cause spontaneous
combustion.
12. Do not weld or flame cut in a confined space without taking
special precautions. Poor ventilation can lead to asphyxiation. Accumulation of fuel gas can explode. Always practice
“confined space” safety.
17. If you must weld or flame cut with combustible or volatile
materials present, take extra precautions, make out a hot
work permit, and provide for a lookout, etc. This will minimize
the chance of fires. (Refer to Ref. 25.)
13. When assembling apparatus, crack gas cylinder valve before
attaching regulators (cracking means opening the valve on a
cylinder slightly, then closing). This blows out any accumulated foreign material. Make sure that all threaded fittings are
clean and tight. The impact of foreign material can mcause
regulators to explode, when they are pressurized upon opening of the cylinder valve.
18. Do not weld or flame cut on containers that have held combustibles without taking special precautions. The heat of the
flame can ignite residual gases and cause an explosion. The
heat can cause the release of hazardous fumes. Always assure a container is clean and safe for welding or cutting.
19. Do not weld or flame cut into a sealed container or compartment without providing vents and taking special precautions.
The heat of the flame can cause gases to expand. The
increased pressure can lead to an explosion.
14. Always follow the torch manufacturer’s instructions when
lighting the torch. This will prevent damage and the release
of excess gases.
20. Do not repair damaged hoses with tape. Only trained persons
should repair hoses. Gas leaks can cause fires and explosions and, in some cases, asphyxiation.
15. Always follow the torch manufacturer’s instructions when
shutting down a torch. This will prevent damage and re-verse
gas flows in the hoses.
16. Use mechanical exhaust when welding or cutting lead,
cadmium, chromium, manganese, brass, bronze, zinc, or
galvanized steel. These “low allowable-limit materials” can
cause serious injury. Ventilation will prevent overexposure
(Refer to Ref. 3)
The Safety in Welding and Cutting standard also provides a precautionary label for oxy-fuel gas processes. This label is shown
in Figure 7.
If the hazards mentioned in this chapter are properly and adequately handled, the welder is as safe as any other industrial
worker. There must be continual vigilance over safety conditions
and safety hazards. Safety meetings should be held regularly.
The safety rules should be reissued annually and they must be
completely understood and enforced.
WARNING:
PROTECT yourself and others. Read and understand this information.
FUMES AND GASES can be hazardous to your health.
HEAT RAYS (INFRARED RADIATION) from flame or hot metal can injure eyes.
• Before use, read and understand the manufacturer’s instructions, Material Safety
Data Sheets (MSDSs), and your employer’s safety practices.
• Keep your head out of the fumes.
• Use enough ventilation, exhaust at the flame, or both, to keep fumes and gases from
your breathing zone and the general area.
• Wear correct eye, ear, and body protection.
• See American National Standard ANSI Z49.1, Safety In Welding, Cutting, and Allied
Processes, published by the American Welding Society, 550 N.W. LeJeune Rd., Miami,
FL 33126; OSHA Safety and Health Standards are published by the U.S. Government
Printing Office, 732 North Capitol Street NW, Washington, DC 20401.
DO NOT REMOVE THIS INFORMATION
Figure 7 - Precautionary Information for Oxyfuel Gas Processes and Equipment
74
Terminal
protection
Terminal
protection
closed
open
Figure 8 - Insulating devices on terminals of a welding machine
2. Electrical Shock Hazard
A shock hazard is associated with all electrical equipment. This
includes extension lights, electric hand tools, and all types of
electrically powered machinery. Welding equipment operators
should note that ordinary household voltage (115 v) is higher than
the output voltage of a conventional arc welding machine.
the generator is mechanically connected to the electric motor.
However, the metal frame and case of the motor generator must
be grounded since the high voltage input from the main lines
come into the case. In transformer and transformer rectifier type
machines, the primary and secondary transformer windings are
electrically isolated from each other by insulation. This insulation
may become defective if proper maintenance practices are not
observed. The metal frames and cases of transformers and transformer rectifier machines must be grounded to earth. Normally,
the work terminal of the welding machine should not be grounded
to earth. However, it is possible to connect the work terminal to
a grounded enclosure when ANSI Z49.1 Section II requirements
are followed.
Use only welding machines that meet recognized national
standards. Most industrial welding machines meet the National
Electrical Manufacturers Association (NEMA) standards for electric welding apparatus.(9) This is mentioned in the manufacturer’s
literature and is shown on the nameplate of the welding machine.
In Canada, approval by the Canadian Standards Association
(CSA) is required for certain types of welding machines and this
is also indicated on the nameplate.(10) In certain parts of the U.S.,
and for certain applications, the Underwriters Laboratory (UL) approval is required.(11) The NEMA specification provides classes of
welding machines, duty cycle requirements, and no load voltage
maximum requirements.
Disconnect switches should be employed with all power sources
so that they can be disconnected from the main lines for maintenance and to prevent electrical shocks.
It is extremely important when paralleling transformer welding
machines that the phases of the power line be accurately identified. Parallel machines must be on the same phase and “in phase”
with one another. It is relatively easy to check this by connecting
the work leads together and measuring the voltage between the
electrode holders of the two machines. This voltage should be
practically zero. If it is double the normal open circuit voltage,
it means that either the primary or secondary connections are
reversed. If the voltage is approximately 1-1/2 times the normal
open circuit voltage it means that the machines are connected to
different phases of the three phase power line. Corrections must
be made before welding begins. Refer to ANSI Z49.1 for further
information.
In order to comply with the OSHA requirements, manufacturers
have made changes to improve the safety of the machines. This
includes methods to protect the output terminals with insulating
devices. A typical method is shown in Figure 8. Manufacturers
have also made the ventilation slots smaller so that the fingers of
the welder cannot come in contact with high voltage inside the
case. They have also changed the cases of the welding machines
so that “tools” are required to open the case where high voltage
is exposed.
Only insulated type welding electrode holders should be used for
shielded metal arc welding. Semiautomatic welding guns for continuous wire processes should utilize low voltage control circuits
so that high voltage is not brought into the hands of the welder. In
fully automatic equipment higher voltages are permitted, but are
inaccessible to the operator during normal operation.
When large weldments, like ships, buildings, or other metal
structures are involved, it is normal to have the work terminal of
many welding machines connected to the metal structure. When
welders are working on one structure sufficiently close to each
other, and someone is likely to touch the exposed parts of more
than one electrode holder simultaneously, machines must be
connected to minimize the shock hazard. However, this must be
done with care, by a qualified person, and according to the teachings of ANSI Z49.1 Section II. It is extremely important that the
machines be connected to the proper phase and have the same
polarity. This can be checked by measuring the voltage between
the electrode holders of the different machines mentioned above.
The situation can also occur with respect to direct current power
Installation
All electric arc welding machines must be installed in accordance
with the National Electrical Code(12) and all local codes. Installation
instructions are included in the manufacturer’s manual that accompanies the welding machine. If applicable, follow lockout/tagout
procedures(37). The manual also gives the size of power cable that
should be used to connect the machine to the main line. Motor
generator welding machines feature com-plete separation of the
primary input power and the welding circuit output power since
75
sources when they are connected to a common structure. If one
machine is connected for straight polarity electrode negative and
one for reverse polarity electrode positive, the voltage between
the electrode holders will be double the normal open circuit voltage. Precautions should be taken to see that all machines are
of the same polarity when connected to a common weldment.
Simultaneous welding with AC and DC welding machines must
not be permitted on the same weldment unless the teachings of
ANSI Z49.1 Section II are followed.
3. Arc Radiation Hazard
The electric arc is a very powerful source of light–visible, ultraviolet, and infrared. It is necessary that welders and others close
to the welding arc wear suitable protection from the arc radiation.
The brightness and exact spectrum of a welding arc depend on
the welding process, the metals in the arc, the arc atmosphere, the
length of the arc, and the welding current. The higher the current
and arc voltage the more intense the light from the arc. Arc light radiation like all radiation decreases with the square of the distance.
Those processes that produce smoke surrounding the arc have
a less bright arc since the smoke acts as a filter. The spectrum of
the welding arc is similar to that of the sun. Exposure of the skin
and eyes to the arc is the same as exposure to the sun. In spite
of claims by some people, arcs do not emit x-radiation. However,
during the grinding of the thoriated tungsten electrodes, radioactive dust is created. The thoria is slightly radioactive. It creates
the potential hazard of internal radiation exposure by inhalation or
ingestion. That is why it is necessary to control the dust.(13)
The welding electrode holders must be connected to machines
with flexible cables designed for welding application. There shall
be no splices in the electrode cable within 10 feet (3 meters) of the
electrode holder. Splices or connectors, if used in work or electrode
leads, must be insulated to achieve the mechanical strength, quality, conductivity, and water tightness of the original cable.
Finally, it is important to locate welding machines where they have
adequate ventilation and that ventilating ports are so located that
they cannot be obstructed.
Heat is radiated from the arc in the form of infrared radiation.
The infrared radiation is harmless provided that the proper eye
protection and clothing are worn. To minimize light radiation,
screens should be placed around the welding area so that the
people working nearby are shielded from the arc. Welders should
attempt to screen all people from their arc. Screens and surrounding areas, especially welding booths, should be painted with paints
that absorb ultraviolet radiation. The paint finish should have a low
reflectivity to ultraviolet radiation.
Use
Electrode leads and work leads should not be coiled around
the welding machines, nor should they ever be coiled around the
welder. Electrode holders should not be hung where they can
accidentally come in contact with the other side of the circuit.
Electrodes should be removed from holders whenever they are
not in use. It is absolutely essential that power cables or primary
power coming to a welding machine should not be intermixed or
come in contact in any way with the welding cables. The welding
machine must be kept dry and if it should become wet it should
be properly dried by competent electrical maintenance personnel.
In addition, the work area must be kept dry. Welders should never
work in water or damp areas since this reduces the resistance to
the welder and increases potential electrical hazard.
Eye Protection
Welders must use protective welding helmets with special filter
plates or filter glasses. The welding helmets should be in good
repair since openings or cracks can allow arc light to get through
and create discomfort. The curved front welding helmet as shown
in Figure 9 is preferred because it helps reduce the amount of welding fumes that come to the welder’s breathing zone. Fiberglass
or light weight is recommended. Some welding helmets can be
attached to safety hard hats for industrial and construction work.
Welding helmets have lens holders for inserting the cover glass
and filter glass or plate. The standard size filter plate is 2 x 4-1/4
in. (50 x 108 mm). In some helmets, the lens holders will open or
flip upwards. Helmets which accommodate larger-size filter lenses
are also available. The larger filter glasses are 4 1/2 x 5-1/4 in.
(115 x 133 mm) and are more expensive.
Unless they are trained and qualified, welders should not make
repairs on welding machines or associated equipment. Welders
should be instructed not to use tools to open cases of welding
machines. They should be instructed not to perform maintenance
on electrode holders, welding cables, welding guns, wire feeders,
etc. Instead they should be advised to notify their supervisors
of maintenance problems or potential hazards so that qualified
maintenance personnel can make needed repairs.
Maintenance
Welding machines and auxiliary equipment must be periodically
inspected and maintained by competent electricians. During maintenance, the equipment must be disconnected from main power
lines so that there is no possibility of anyone coming in contact
with the high input voltage. If applicable, follow lockout/tagout
procedures.37 Maintenance records should be kept on welding
power supplies. Supervisors and maintenance personnel should
make routine inspection of welding cables and electrode holders,
guns, and work clamps. Welders should report defective equipment or problems to their supervisors. Electrode holders with
worn or missing insulators, and worn and frayed cables, should
be repaired or replaced. Wire feeding semiautomatic equipment
and specialty equipment, designed for gas tungsten arc welding,
normally utilize switch-controlled power contactors. This means
that the electrode wire or torch is electrically “cold” except while
welding unless the switch is operated. The trigger on the welding
gun or foot switch or programmer closes the contactors which
energize the welding circuit. Arc voltage is normally not as hazardous as ordinary household voltage.
The filter glasses or plates come in various optical densities to
filter out a portion of the arc rays. The shade of the filter glass
used is based on the welding process and the welding current.
Figure 10 shows the suggested filter shades according to the
American Welding Society F2.2 Lens Shade Selector.(14). A cover
plate should be placed on the outside of the filter glass to protect
it from weld spatter. Plastic or glass plates are used. Some welders
also use magnifier lenses behind the filter plate to provide clearer
vision. The filter glass must be tempered so that it will not break
if hit by flying objects. Filter glasses must be marked showing the
manufacturer, the shade number, and letter “H” indicating that it
has been treated for impact resistance.
Several new types of filter lens for welding helmets have been
introduced. One type of filter glass utilizes a thin layer of liquid
crystals sandwiched between two pieces of clear glass. The liquid crystals employed have the special properties so that when
an electrical signal is placed across them they will change their
ability to transmit light. When electrically changed, liquid crystals produce a screen with the same approximate density as the
76
says that reports of this hazard are based on rumor and have been
thoroughly discredited.
On occasion, welders and others will have their eyes exposed
to the arc for a short period of time. This can result in what is
known as arc burn, arc flash, or welding flash, and is technically
called photokeratitis. It is very similar to a sunburn of the eye.
For a period of approximately 24 hours the welder will have the
painful sensation of sand in the eyes. The condition is normally
of temporary duration and should not last over 48 hours. People
who receive an arc flash may not be aware of it at the time. The
first indication of an arc burn may occur 6 to 12 hours later. Temporary relief can be obtained by using eyedrops and eye washes.
If the painful sensation lasts beyond one day, a doctor should be
consulted for treatment.
Transparent Welding Curtains
Transparent welding curtains or screens made of plastic film
are sometimes used for screening welding operations. Figure 11
shows an application of these screens. The material is relatively
tough, available in large sheets, and comes in blue, green, gray
and yellow. Tests have been performed by the National Institute of
Occupational Safety and Health(l5), and it is concluded that these
curtains provide protection in the ultraviolet range.
Figure 9 - Curve type helmet offers best protection.
welding filter glass. A photosensor on the helmet is triggered by
the light from the arc. Within a fraction of a second this signal is
transmitted through the liquid crystals which change the density
of the filter glass. Another type of filter becomes darker when
exposed to the bright light of the arc. These filters are becoming
more popular. They eliminate the need for opening and closing or
repositioning the welding helmet by a rapid head nod.
Safety glasses should always be worn in an active work area
underneath the welding helmet. These are required since the
helmet is usually lifted when slag is chipped or welds are ground.
Tinted safety glasses with side shields are recommended. People
working around welders should also wear tinted safety glasses
with side shields. Safety glasses should meet all the requirements
of ANSI Z87.1 “Occupational and Educational Personal Eye and
Face Protection Devices” standard.
Contact Lenses
Courtesy of Wilson Industries, Inc.
and the Welding Journal, American Welding Society.
The wearing of contact lenses by welders is the subject of erroneous and recurring rumors. Various authorities, including the
National Society to Prevent Blindness, the Contact Lens Association of Ophthalmologists, and others, state that the normal eye
protection required by OSHA for welding, brazing and soldering
is the same with or without contacts, The American Optometric
Association adopted a policy statement saying that contact lenses
may be worn in hazardous environments but only with appropriate normal safety eye wear. Contact lenses themselves do not
provide eye protection in the industrial sense. As a general rule,
if an employee habitually wears contact lenses, they should be
allowed to wear their lenses but only with the addition of normal
safety equipment. It was further noted that the radiation from a
welding arc or flash is not intense enough to affect the materials
from which contact lenses are made. Welders or anyone who
may be exposed to a welding flash or arc must always wear appropriate safety goggles over their contact lenses. Eye experts
unanimously agree that it is impossible for an electric arc to weld
contact lenses to the eye. The American Optometric Association
Figure 11 - Welding station using transparent welding screen.
The material is flame resistant. In no case can this curtain material
be substituted for filter glass in helmets. It is intended to protect
nearby workers from arc flash and improve communication with
welders. In some applications it may be an improvement over
opaque curtains or shields.
Welding operations should be isolated from metal-degreasing
or solvent-cleaning operations. Chemical-degreasing tanks may
use trichloloethylene or other chlorinated hydrocarbons which
will decompose to poisonous phosgene gas when exposed to
arc (ultraviolet) radiation. Poisonous phosgene gas can build up
to dangerous concentrations which will be potentially harmful.
Fortunately, the odor of phosgene gas is quickly recognized (it
smells like new mown hay) and if it is detected, the area should
be evacuated and ventilated.
77
Guide lor Shade Numbers
Shod•num.btn are
Eleetrode Sitt
ill.< mm)
Art Cun-ent
(Amperes)
Less t11an 3/32 (2.4)
:l/32-S/32 (2.4-4.0)
5132-114(4 .4)
Mor< th.an 114 (6.4)
Ltsolhan60
60-160
160-2SO
Pr oss
Shielded Metal AJ<. Welding
(SMAW)
(from AWS 1'2.2. 1..1111 Shade Selt<tor)
liven as a guide only and may bo varied 10suit indhidual needs.
Gas MeLal Arc Welding (GMA W)
250-SSO
Cutting (CAC A)
(Heavy)
PI"""' Are Welding (PAW)
Plaam• Are Culling (PAC)
<Comfon)
7
8
10
II
10
12
14
7
60-160
11
160-2SO
10
10
12
14
8
10
12
14
250-500
(Light)
Shad<
10
(FCAW)
Air Carbon Arc
Suggested•
Slwi<No.
Less than 60
11\d Flux Con:d Arc Welding
Gil$ TWlgs!en Arc Welding
(OTAW)
Mintmwn
Protcclive
Ltnlllan50
lO-ISO
ll0-500
8
10
L<>t thm500
10
12
14
1000
II
les.s th., 20
20-100
8
10
100-400
10
40(400
11
12
14
6
610
s
Lcsslll:ut 20
4
4
20-40
40-60
5
s
6
8
8
6(H()
80-300
8
3()()..400
9
10
6
9
12
14
Torch Bruing (TB)
3 or4
Torch Soldering (TS)
2
14
Carbon AJ<. Welding (CAW)
PlaJe ThickMss
mm
in.
Suggc31ed•
Shade No.
(Comfon)
Oxyluel Gas Welding (OFW)
Light
Medium
Heavy
Under \18
tiS ro tn
om 1n
Undcr3
3 to 13
Over 13
4od
S or6
OXygen Cutting (0C)
LiCht
Medium
Heavy
Under 1
1106
Over 6
Under 25
2Sto I SO
Over ISO
3or 4
4orS
Sor6
6 or 8
•As a rule of thumb start with a shade that is too dark to see the weld zone. Then go to a lighter shade which
gives sufficient view of the weld zone without going below the minimum. In oxy fuel where the torch and/or
the flux produces a high yellow light, it is desirable to use a filter lens that absorbs the yellow or sodium line
of the visible light spectrum.
Figure 10- Eye protection filter shade selector
78
As a protective measure, degreasing operations should be at
least 200 ft away from welding operations. If this is not possible
adequate ventilation is required. Care should be taken when welding parts that have been cleaned with these solvents. The parts
must be thoroughly dry before welding.
Many investigations and tests have been made to determine the
composition of fumes generated. This is presented in the AWS
publication “The Welding Environment”(16) mentioned previously,
and was based on using different welding and allied processes.
Much data is presented in the document “Fumes and Gases in
the Welding Environment”.(17) Some research to determine fume
generated by arc welding is given by the document “Characterization of Arc Welding Fume”.(18) In general, welding with mild steel
electrodes on clean steel produces fumes containing a high proportion of iron oxide and small amounts of calcium oxide, titanium
oxide, and amorphous silica.
Ultraviolet rays from the arc, particularly the high-intensity gas
tungsten arc on aluminum, react with the oxygen in the atmosphere
to produce ozone. Ozone is an active form of oxygen which has
a pungent characteristic smell. It is sometimes evident after a
lightening strike or in the generating room of a power house. It is
relatively unstable and quickly changes back to oxygen. Exposure
to ozone will cause a burning sensation in the throat, coughing or
chest pains or wheezing in the chest during breathing. Ventilation
should be used so that ozone concentration will be below the
threshold limit values.
The fumes produced when welding with low hydrogen type
electrodes contain the oxides mentioned above and fluorides.
When welding with stainless steel electrodes, the iron oxide is
lower but there are now oxides of chromium and nickel as well as
fluorides. Electrode manufacturers supply Material Safety Data
Sheets (MSDSs) for each container of filler metal, which show
the composition of the coating on electrodes, fluxes or flux cores.
MSDSs may also include the composition of particulate matter
produced as these electrodes are consumed in the arc. Due to
the high temperature of the arc, the composition of the particulate
matter is different than that of the coating. Similar information is
provided for oxyfuel gas materials.
Warning signs should be posted in welding areas advising visitors
not to look at the arc since arc flash may injure eyes.
4. Air Contamination Hazard
Arc and flame, welding and cutting, produce air contamination.
This is seen as smoke rising above the welding or flame operation.
The smoke or plume appears similar to smoke rising from a wood
fire. Normal ventilation practice reduces the hazards of smoke from
welding, cutting, or from an open fire. The fumes contain two types
of air contamination - particulate matter and gases.
The flux cored arc welding process can produce a great deal of
particulate matter, or smoke. However, for a similar amount of
weld metal deposited, the particulate matter of SMAW and FCAW
is similar. The gas metal arc welding process produces much
less particulate matter. The submerged arc process produces a
very small amount of particulate matter as do the gas tungsten
and plasma arc welding processes.
The welding industry sponsored research to investigate the
welding atmosphere and to recommend precautions to avoid
potential hazards. This includes a series of reports entitled “Effects
of Welding on Health”(4) mentioned previously, starting in 1979
and continuing. The American Welding Society’s study entitled
“The Welding Environment”(16), and several other studies indicate
that there is no significant health difference between welders and
nonwelders when proper ventilation is used.
The base material is another source of particulate matter. The
base metal, when melted by an arc, may volatilize and produce airborne contaminants. Chromium and nickel compounds are found
in the fume when stainless steels are arc welded. The International
Agency for Research on Cancer has determined chromium and
nickel welding fumes are possibly carcinogenic to humans (Group
2B)(40). The American Welding Society has developed a standardized method for measuring and determining the particulate
matter produced by different welding processes. This method is
outlined by the AWS document “Methods for Sampling Airborne
Particulates Generated by Welding and Allied Processes”.(19) By
using this technique, measurements can be made to determine
contamination.
A precautionary label which was introduced in 1967 stated “Caution: Welding may produce fumes and gases hazardous to health.
Avoid breathing these fumes and gases. Use adequate ventilation.
See American National Standard Z49.1 Safety in Welding and Cutting” published by the American Welding Society”.
This precautionary label has been revised to be more encompassing and is shown in Figure 1. A similar precautionary label for
oxy-fuel gas processes is shown in Figure 7. The purpose of these
labels is to remind welders and others of the potential hazards.
That way adequate steps can be taken to protect personnel from
concentrations that might be harmful. The potential harm from
fumes and gases depends upon many factors including:
Certain metals identified as “low allowable-limit materials” in
ANSI Z49.1(3) should not be welded without the use of mechanical
exhaust systems or respiratory protection. These low allowablelimit materials are antimony, arsenic, barium, beryllium, cadmium,
chromium, cobalt, copper, lead, manganese, mercury, nickel,
ozone, selenium, silver, and vanadium. Arc welding should not
be done on any of these materials unless mechanical ventilation
is employed or unless the welder uses respiratory protection.
• The chemical composition of the particular matter;
• The concentration at the welder’s breathing zone;
• The length of time of exposure to these fumes and gases.
Airborne contaminants are produced when welding or cutting
on coated materials. Base metal coated with any of the above
metals must be treated with caution and mechanical ventilation
or respiratory protection must be provided. Other coatings such
as paint, varnish, plastic, and oil can also generate contamination. The coatings must be removed from the welding area or
else mechanical ventilation must be provided. A serious problem
can be encountered when old steel work is flame cut or welded.
Often older structural steel may be covered with many coats of
lead bearing paint. The heat of the arc or flame will cause the
coating to volatilize and produce smoke containing lead. New
pipe is often coated with a plastic protective material. This must
be removed from the arc area. In every case, adequate ventilation
or respiratory protection for the welder must be employed.
Particulate Matter
Particulate matter is extremely small solids suspended in the
air. Smoke is an example of particulate matter. Particulate matter
includes common house dust, powders, pollen, smog, flash, grinding dust, etc. These range in size from less than 0.1 micron to over
100 microns. The smaller diameter particulates can only be seen
with the microscope, while the larger ones can be seen with the
human eye. The type of particulate matter depends on the welding
process, the type of welding electrode or filler metal, the welding
current employed, the welding location, atmospheric conditions,
wind and so on. It also depends on the compositionof the base
metal being welded, and on any coating on the base metal near
the arc. All welding smoke is not the same and the concentration
can vary over a wide range.
79
Gases
Carbon dioxide is the most common gas produced by the
disintegration of electrode coatings or materials in flux cored
electrode wires. The CO2 is used to help protect the arc area from
the atmosphere. There is a possibility of carbon monoxide, a very
hazardous gas, being produced in the arc. Carbon monoxide,
however, readily recombines with available oxygen in the heated
atmosphere to produce CO2 gas. Carbon monoxide is rarely found
beyond a short distance away from the arc area.
Gases are produced or may be involved in many of the processes
using flames. Gases are produced as products of combustion with
the fuel gas processes. Gas is produced by some of the constituents of the coating on the shielded metal arc welding electrode or
the material contained in the core of a flux cored electrode wire.
These coatings and contained materials are designed as a part
of the consumable filler metal to produce gases to help shield the
arc area from the atmosphere. Packages of filler metals also carry
a precautionary label.
Ozone is sometimes produced by the ultraviolet light emitted
by the arc. Ozone is a form of oxygen with a chemical formula
Fluxes used for gas welding and brazing, and for submerged arc
welding and electroslag welding will also produce gases. Brazing
and gas welding fluxes sometimes contain fluoride which, upon
heating or melting, produces small amounts of fluorine in the atmosphere. Packages containing these types of fluxes are labeled
as shown in Figure 12. Brazing filler metals containing cadmium
are labeled as shown in Figure 13. These products produce potentially harmful fumes and gases and proper ventilation should
be employed.
of 03 and is over 1 1/2 times as dense as oxygen. Ozone is more
often produced in the arc welding processes that do not employ
fluxes or coatings. Ozone changes back to normal oxygen a short
distance from the arc.
The gas shielded welding processes use various gases to shield
the arc area from the atmosphere. Inert gases are used for gas
tungsten arc welding and for plasma arc welding, but active gases
or mixtures of active and inert gases are used for gas metal arc
and flux cored arc welding. Adequate ventilation is required to
remove these gases from the welders breathing zone.
DANGER: CONTAINS CADMIUM
WARNING: CONTAINS FLUORIDES:
Protect yourself and others. Read and understand this
information.
Protect yourself and others. Read and understand this
information.
FUMES AND GASES CAN BE HAZARDOUS TO YOUR
HEALTH. BURNS EYES AND SKIN ON CONTACT. CAN
BE FATAL IF SWALLOWED.
FUMES ARE POISONOUS AND CAN KILL.
• Before use, read and understnd the manufacturer’s
instructions, Material Safety Data Sheets (MSDSs),
and your employer’s safety practices.
• Before use, read and understand the manufacturer’s Instructions, Material Safety Data Sheets
(MSDSs) and your employer’s safety practices.
• Keep your head out of the fume.
• Use enough ventilation, exhaust at the arc, or both,
to keep fumes and gases from your breathing zone
and the general area.
• Avoid contact of flux with eyes and skin.
• Do not take internally.
• Keep children away when using.
• See American National Standard ANSI Z49.1, Safety
In Welding, Cutting, and Allied Processes,
published by the American Welding Society,
550 N.W. LeJeune Road, Miami, FL 33126;
OSHA Safety and Health Standards, are published
by the U.S. Government Printing Office, 732 North
Capitol Street NW, Washington, DC 20401.
• Do not breathe fumes. Even brief exposure to high
concentrations should be avoided.
• Use enough ventilation, exhaust at the arc, or both,
to keep fumes and gases from your breathing zone
and the general area. If this cannot be done, use air
supplied respirators.
• Keep children away when using.
• See American National Standard ANSI Z49.1 Safety
in Welding, Cutting, and Allied Processes,
published by the American Welding Society,
550 N.W. LeJeune Road, Miami, FL 33126;
OSHA Safety and Health Standards are published
by the U.S. Government Printing Office, 732 North
Capitol Street NW, Washington, DC 20401.
First Aid: If contact in eyes, flush immediately with clean
water for at least 15 minutes. If swallowed, induce vomiting. Never give anything by mouth to an unconscious
person. Call a physician.
• First Aid: If chest pain, shortness of breath, cough,
or fever develop after use, obtain medical help
immediately.
DO NOT REMOVE THIS INFORMATION
DO NOT REMOVE THIS INFORMATION
Figure 12 - Precautionary information for brazing and welding fluxes containing fluorides
Figure 13 - Precautionary information for brazing filler metals containing cadmium
80
sample the atmosphere before entering an enclosed compartment.
Confined or Enclosed Areas
Oxygen deficiency can be another potential hazard for workers in
All arc and flame operations and associated operations, carried
out in confined or restricted spaces must be adequately ventilated
to prevent the accumulation of toxic materials, combustible gases
or oxygen deficiency.
an enclosed area. When using the gas shielded metal arc process,
the two most popular shielding gases are both heavier than air.
Both argon and carbon dioxide weigh approximately 1-1/2 times
the weight of air and will displace it. Without proper ventilation,
the used shielding gas will, in time, displace the air so that the
atmosphere at the welder’s breathing zone will become rich in the
shielding gas atmosphere and there will be a deficiency of oxygen.
If the oxygen content in the breathing zone is reduced by 5% or
more, serious damage or death can be the result to the worker.
Whenever there is doubt, the atmosphere in an enclosed area must
be monitored with a portable oxygen indicator.
Generally speaking, an enclosed area, also called a confined
space, is a relatively small or restricted space such as a tank,
vat, pressure vessel, boiler, compartment, small room, tunnel or
any enclosure which may have poor ventilation. It may also have
restricted entry and exit. Even a large room or enclosure without
proper ventilation can be considered a confined space. The upper
corner of a room can even be a confined space when lighter than
air gases can accumulate. An open pit can be a confined space
when heavier than air gases can accumulate. These types of areas
pose problems not only for welders, but for anyone working inside
them. The potential hazards range from deficiency of oxygen, too
much oxygen, poisonous gases, flammable or explosive gases,
as well as the accumulation of dense smoke or particulate matter. Welding, flame cutting or allied processes should never be
started without taking special precautions. Only work in such
areas after they have been declared safe for work by supervision
or management.
Mechanical ventilation must be used for ventilating enclosed
areas. Preferably both air exhaust systems and fresh air supply
systems should be employed. When welding or cutting in any
area that cannot be adequately mechanically ventilated, positive
pressure, self contained breathing apparatus, or air line respirators must be used.
If you have questions concerning monitoring atmospheres or
monitoring instruments, or special breathing apparatus, contact
your company’s safety department or your local fire department
or State Industrial Commission representative. Never ever work
in a confined or enclosed area unless it has been declared safe
by a qualified person, supervision, or management.
Everyone knows the risk of remaining in a closed garage with an
automobile engine running. This can also be a potential problem
with an engine driven welding machine. The exhaust gas given
off by the engine should always be channeled to the outside. In
enclosed areas, even large rooms, an engine driven welding machine if not exhausted to the outside can produce a build-up of
carbon monoxide and carbon dioxide gas hazardous for people
working within the room.
Ventilation
Adequate ventilation must be provided for all welding, cutting,
brazing and related operations. Adequate ventilation means sufficient ventilation so that hazardous concentrations of airborne
contaminants are below the allowable levels specified by OSHA
or the American Conference of Governmental Hygienists (ACGIH).
Adequate ventilation depends on many factors including the following:
The same problem can occur when preheating weldments using the combustion of fuel gases, coal or charcoal for heat. The
burning of these fuels will produce carbon monoxide and carbon
dioxide which must be exhausted to the outside.
A “lookout” or watcher or attendant must be assigned to continually watch the welders and other workers, and have voice contact
to those in the enclosed area. One lookout or attendant should
be assigned to a team of welders working in a specific enclosed
area. In some hazardous cases, lifelines with harnesses should
be employed. Lifelines should be attached so that workers can
be removed through manholes with ease.
1. Volume and configuration of the space where welding occurs.
Prior to entering enclosed areas, special precautions should
be taken to determine the atmosphere within the enclosed area.
Explosive concentrations of gases sometimes build up in an enclosed area. This could occur if an acetylene torch is left inside
the compartment, or fuel gas could leak into the compartment,
or products of decomposition were enclosed. The atmosphere
within the enclosed area must be tested prior to entering the area.
Portable explosimeters are available for sampling the atmosphere
to determine if an explosive mixture is present.
5. Location of welders’ and other persons’ breathing zones in
relation to the contamination, contaminants, or sources.
2. Number and type of operations generating contaminants.
3. Allowable levels of specific toxic or flammable contaminants
being generated.
4. Natural air flow and general atmospheric conditions where
work is being done.
Adequate ventilation can be obtained by using the following,
either singly or in combination:
1. Natural ventilation
2. General mechanical ventilation
3. Local exhaust ventilation
Natural ventilation occurs when the welding is done out of doors.
Natural ventilation can occur indoors, but only if the welding
shop is sufficiently large. This means a space of 10,000 cu. ft.
(284 cu. meters) per welder, with a ceiling height of more than 16
ft. (5 meters), and does not contain partitions, balconies, or other
structural barriers that obstruct ventilaton. Natural ventilation
must be supplemented when welding on hazardous materials.
Another problem relating to confined or enclosed areas involves
oxygen enriched atmospheres. Oxygen enriched atmospheres can
result from a leak in the oxygen line of an oxy flame cutting torch.
Normally the atmosphere contains approximately 21% oxygen. If
the oxygen would increase 5% or more, the enriched atmosphere
would support rapid combustion, or even an explosive mixture.
Striking an arc or starting a flame could be extremely hazardous.
Clothes, oily cloths, and other combustible items would burn
with an almost explosive violence. Oxygen from a compressed
gas cylinder should never be used to help ventilate an enclosed
compartment. It should never be used in place of compressed air
suitable for breathing. When in doubt, portable instruments indicating oxygen concentration are available and should be used to
General mechanical ventilation using roof exhaust fans, wall
exhaust fans, or similar air movers must be used if the space per
welder is less than 10,000 cu ft. (284 cu meters), or if the ceiling
height is less than 16 ft. (5 meters), or if the shop includes partitions, balconies, or other structural barriers that obstruct cross
ventilation. General mechanical ventilation is recommended to
maintain a low level of airborne contaminants, and to prevent
81
accumulation of explosive gas mixtures. General mechanical
ventilation is used for individual welding booths as shown in Figure
Local exhaust ventilation can be obtained by the following
methods:
14. If general mechanical ventilation is not sufficient to maintain
the general background level of airborne contaminants below the
recommended limits, then local exhaust ventilation or local forced
ventilation is required.
1. Use of freely movable hoods, shown in figure 15, placed near
the arc.
2. A fixed enclosure with a top and not less than two sides
surrounding the welder with a sufficient rate of air flow.
Local exhaust ventilation requires the use of fixed or movable
exhaust hoods placed as near as practical to the work and able
to capture sufficient contaminants to keep the level below the
requirements.
3. Tables with down draft ventilation.
4. A smoke exhaust nozzle is built into the welding gun such
as shown in Figure 16. Similar suction devices are available
for covered electrode welding.
Figure 14 - Welding booths with mechanical ventilation
Photo courtesy of Kemper America, Inc.
Photo courtesy of Bernard Welding Equipment
Figure 15 - Moveable hood for local exhaust
Figure 16 - OXO APX® Air-cooled MIG welding
gun showing smoke exhaust nozzle
82
This smoke exhaust gun system is based on collecting the
fumes as close as possible to the point of generation or at the
arc. This method of fume exhaust works well with semi automatic
and robotic welding, particularly when using flux cored welding
electrodes. The operation of this exhausting system is shown in
Figure 17, which shows the smoke exhaust gun on and off. This
system has proven economical since much less air is exhausted.
This reduces the need for massive air make-up units to provide
heated or cooled air to replace the air exhausted.
In all cases where local exhaust ventilation is used, the exhaust
air should be filtered before it is discharged into the atmosphere
or returned to the welding shop.
The use of movable hoods for local exhaust systems is further
illustrated in Figure 18, which provides some details concerning the
nozzle pick-up design. It shows typical volumetric air flow velocities to meet exhaust requirements. This is based on the Industrial
Ventilation: Manual of Recommended Practice.(20)
local forced ventilation means a local air moving system such as
a fan placed so that it moves the air at right angles to the welder
across the welder’s face. It should produce a velocity of approximately 100 ft. per minute (30 meters per minute), and be maintained
for a distance of approximately 2 ft. (.6 meters) directly across the
work area. Be careful of how the air is directed. Keep it away from
the arc zone. Higher velocities than 100 fpm can disturb the arc
shielding. This will result in a defective weld.
Figure 17 - Smoke exhaust gun on and off.
Two American Welding Society documents provide guidance in
making these types of investigations—Evaluating Contaminants
in the Welding Environment, A Sampling Strategy Guide(21), and
Laboratory Method for Measuring Fume Generation Rates and
Total Fume Emission of Welding and Allied Processes.(22) By following the teachings of these documents, it can be determined if
the sample meets or exceeds the prescribed exposure limits. The
threshold limit values (TlV®) of most hazardous materials are established by the American conference of governmental Industrial
Hygienists, “Threshold limit Values for chemical Substances and
Physical Agents in the Work Room Environment.”(6) The determinations found in the welder’s breathing zone should be below these
TlV® limits. OSHA publishes permissible exposure limits (PEls).
Analytical work of this type must only be done by highly qualified
people who are familiar with welding operations, testing and sampling techniques, as well as the analytical methods to determine
the amounts of contaminants found in the air samples taken from
the welder’s breathing zone. (TLV® is a registered trademark of
the American Conference of Governmental Industrial Hygienists.)
Air velocity is relatively easy to measure using a velometer or air
flow meter, thus it is easy to check the efficiency of local forced
ventilation. Down-draft welding work tables are popular in Europe
but have not been used to a very large degree in the united States
or other parts of the world.
There is one foolproof method to determine if proper ventilation is being provided. This is done by collecting samples of the
atmosphere at the welder’s breathing zone under the helmet. A
special pick-up device is mounted inside the welding helmet and
atmosphere samples are collected for a specific time period. The
samples are then chemically analyzed in calibrated instruments
which determine the value of all elements that are found in the
welder’s breathing zone.
PORTABlE ExHAuST
PlAIn DucT
x IncHES
cFM
up to 6
6-9
9 - 12
335
755
1335
FlAngE OR cOnE
cFM
250
560
1000
FAcE VElOcITy = 1500 FPM
DucT VElOcITy = 3000 FPM MInIMuM
PlAIn DucT EnTRy lOSS = 0.93 DucT VP
FlAngE OR cOnE EnTRy lOSS = 0.25 DucT VP
gEnERAl VEnTIlATIOn, WHERE lOcAl ExHAuST cAnnOT BE
uSED:
ROD, DIAM
cFM / WElDER
5/32
3/16
1/4
1000
1500
3500
3/8
4500
OR
For toxic materials, higher airflows are
necessary and operator may require
respiratory protection equipment.
Figure 18 - Moveable hood for local exhaust
83
A. For open areas where
welding fume can rise away
from the breathing zone:
cfm required = 800 x lb/hour
rod used
B. For enclosed areas or
positions where fume does
not readily escape breathing
zone: cfm required = 1600 x
lb/hour rod used.
5. Fire and Explosion Hazard
boiling point of water (212°F or 100°C). If fire occurs on or near an
acetylene cylinder the fuse plug will melt. The escaping acetylene
may be ignited and will burn with a roaring sound. Immediately
evacuate all people from the area. It is difficult to put out such
a fire. The best action is to spray water on the cylinder to keep
it cool and to keep all other acetylene cylinders in the area cool.
Attempt to remove the burning cylinder from close proximity to
other acetylene cylinders, from flammable or hazardous materials, or from combustible buildings. It is best to allow the gas to
burn rather than to allow acetylene to escape, mix with air, and
possibly violently explode.
A large number of the fires are caused by cutting and welding in
areas not specifically designated or approved for such work. The
three elements of the fire triangle, fuel, heat, and oxygen are present in most welding operations. The heat is from the torch flame,
the arc or from hot metal. The fuel is from the fuel gas employed,
or from combustibles in the welding area. The oxygen is present
in air but may be enriched by oxygen used with the fuel gas. Many
of these fires have been caused by sparks and spatter. These are
globules of oxidized molten metal which can travel up to 35 ft. (11
meters). Sparks may also fall through cracks, pipe holes, or other
small openings in floors and partitions and start fires in other areas.
That is why you should always be alert to fires in hidden areas.
If the fire on a cylinder is a small flame around the hose
connection, the valve stem, or the fuse plug, try to put it out as
quickly as possible. Immediately move the cylinder out-of-doors
where the leak may be fixed. A wet glove, wet heavy cloth, or
mud slapped on the flame will frequently extinguish it. Thoroughly
wetting the gloves and clothing will help protect the person approaching the cylinder. Avoid getting in line with the fuse plug
which might melt at any time.
Hot pieces of metal may come in contact with combustible
materials and start fires. Fires and explosions have also been
caused when this heat is transmitted through walls to flammable
atmospheres or to combustibles on the other side. Anything that
is combustible or flammable is susceptible to ignition by cutting
and welding. Welding or cutting on metal which is in contact with
foam insulation is especially hazardous. All insulating organic
foams whether indicated fire retarded or not, should be considered
combustible and handled accordingly.
Apparatus
Gas welding or cutting apparatus must be listed with a nationally
recognized independent testing laboratory. When ordering gas
welding or cutting apparatus specify that it must carry the Underwriters Laboratory (UL) or Factory Mutual Engineering Corporation
(FM) or equivalent seal of approval.
Cutting and welding fires can be prevented by eliminating or
protecting all combustibles in the welding area. Welding arcs or
oxy fuel gas flames rarely cause fires when used in areas designed
for welding and cutting. Fire and explosion hazards should be
considered from two points of view: welding in designated areas
and welding with portable equipment in all other areas.
Gas apparatus must be properly maintained and repaired by
qualified people. All too often apparatus is allowed to deteriorate
before maintenance is performed. Welding gauges, welding regulators, welding torches, welding tips, etc., should all be carefully
inspected periodically and maintained at the first sign of deterioration. Oil or grease should never be used on any gas welding
or cutting apparatus. These and the following steps will prevent
leaks, as well as fires and explosions.
Safe Work Areas
A workplace can be designed for safe welding and cutting
operations. Floors, walls, ceilings, etc., must be constructed of
noncombustible materials. The work area must be kept clean and
free of combustible and flammable materials. All fuel gas lines,
manifolds, branches, etc., must be installed in accordance with
specifications and codes.
Only approved gas hoses should be used with oxy-fuel gas
equipment. The size of hose should be matched to the connectors,
the regulators and torches. In the United States the color green
is used for oxygen, red for the acetylene or fuel gas and black for
inert gas and compressed air. International standards use different
colors. The thread connections on hoses are right-handed for inert
gases and oxygen and left-handed for fuel gases. The nuts on fuel
gas hoses are identified by a groove machined in the center of
the nuts. Hoses should be periodically inspected for burns, worn
places, or leaks at the connections. They must be kept in good
repair and should be no longer than necessary. Remember, these
steps will help prevent leaks, fires and explosions.
Fire-fighting equipment must be installed in the welding workshop areas. The types of extinguishers for the possible different
types of fires should be available and identified for the type of fires
that might occur. Management must assure that supervisors and
workers are trained in safe work practices.
Fuel Gases
There are a number of different fuel gases used for welding and
flame cutting. The most familiar is acetylene, but propane, natural
gas, methylacetylene-propadiene stabilized, etc. are also used.
Acetylene is sometimes produced on the premises by an acetylene generator. An acetylene generator uses carbide and water
to produce acetylene which is then piped through the plant to
the welding and cutting departments. Acetylene generators must
be installed properly, maintained properly, and operated only by
trained and qualified people. Carbide must be stored properly and
never exposed to moisture or water which creates more acetylene
to feed fires and cause explosions.
Hot Work Permits
To prevent fires and explosions, welding permits or, as they are
sometimes called, “hot work permits”, are often required. These
permits must be used when welding or flame cutting is done where
fires and explosions may occur. Management and supervision
must assure workers are trained to recognize the need for hot
work permits.
One source of sample hot work permits is the National Safety
Council. The National Fire Protection Association (NFPA)(25) Publication 51B, “Standard for Fire Prevention During Welding, Cutting,
and Other Hot Work,” requires the use of hot work permits in areas
not designated for hot work. Their sample permit form is shown in
Figure 19. Your casualty insurance company may have similar permits. The National Fire Protection Association also recommends
the use of a fire watcher or person trained in fire safety procedures.
Supervision must assure hot work permits and firewatchers are
used when required. When using portable equipment, these are
Acetylene cylinders and other fuel gas cylinders should be stored
in a specified well-ventilated area or outdoors away from oxygen
and in the vertical position. This will avoid the accumulation of
explosive gas mixtures. All cylinders in storage should have their
caps on and cylinders, either filled or empty, should have the valve
closed. In a fire situation there are special precautions that should
be taken for acetylene cylinders.(23) All acetylene cylinders are
equipped with one or more safety relief devices constructed with
a low melting point metal. This fusible metal melts at about the
84
invaluable and can avoid the headlines stating that the fire was
caused by “a welder’s torch.”
areas and try to extinguish them only if it is obviously within the
capacity of the extinguishers. Otherwise, they must sound the
alarm immediately. More than one firewatcher may be needed
when hidden hazards or multiple hazardous areas are present.
Firewatchers are persons trained to understand the inherent
hazards of the work site and the hot work. They must assure
conditions are safe during the hot work; and they must have the
authority to stop the work if unsafe conditions develop. They shall
have fire extinguishing equipment readily available and be trained
in its use. They must be familiar with procedures for sounding an
alarm in the event of a fire. They must watch for fires in exposed
It may be necessary to extend the firewatch period at times.
Supervision must be alert for conditions where smoldering fires
can occur. Fires are known to have occurred many hours after
the hot work has ceased.
HOT WORK PERMIT
Seek an alternative/safer method if possible!
Before initiating hot work, ensure precautions are in place as required by NFPA 51B and ANSI Z49.1.
Make sure an appropriate fire extinguisher is readily available.
This Hot Work Permit is required for any operation involving open flame or producing heat and/or sparks. This work includes,
but is not limited to, welding, brazing, cutting, grinding, soldering, thawing pipe, torch-applied roofing, or chemical welding.
 employee
 contractor
Date
Hot work by
Location/Building and floor
Name (print) and signature of person doing hot work
Work to be done
I verify that the above location has been examined, the precautions
marked on the checklist below have been taken, and permission is
granted for this work.
Time started
Name (print) and signature of permit-authorizing individual (PAI)
Time completed
THIS PERMIT IS GOOD FOR ONE DAY ONLY
 Available sprinklers, hose streams, and extinguishers are in service and operable.
 Hot work equipment is in good working condition in accordance with manufacturer’s specfications.
 Special permission obtained to conduct hot work on metal vessels or piping lined with rubber or plastic.
Requirements within 35 ft (11 m) of hot work
 Flammable liquid, dust, lint, and oily deposits removed.
 Explosive atmosphere in area eliminated.
 Floors swept clean and trash removed.
 Combustible floors wet down or covered with damp sand or fire-resistive/noncombustible materials or equivalent.
 Personnel protected from electrical shock when floors are wet.
 Other combustible storage material removed or covered with listed or approved materials (welding pads, blankets, or curtains;
fire-resisteive tarpaulins), metal shields, or noncombustible materials.
 All wall and floor openings covered.
 Ducts and conveyors that might carry sparks to distant combustible material covered, protected, or shut down.
Requirements for hot work on walls, ceilings, or roofs
 Construction is noncombustible and without combustible coverints or insulation.
 Combustible material on other side of walls, ceilings, or roofs is moved away.
Requirements for hot work on enclosed equipment
 Enclosed equipment is cleaned of all combustibles.
 Containers are purged of flammable liquid/vapor.
 Pressurized vessels, piping, and equipment removed from service, isolated, and vented.
Requirements for hot work fire watch and fire monitoring
 Fire watch is provided during and for a minimum of 30 min. after hot work, including any break activity.
 Fire watch is provided with suitable extinguishers and, where practical, a charged small hose.
 Fire watch is trained in use of equipment and in sounding alarm.
 Fire watch can be required in adjoining areas, above and below.
 Yes
 No
Per the PAI/fire watch, monitoring of hot work area has been extended beyond the 30 min.
© 2008 National Fire Protection Association®
NFPA 51B
Figure 19 - Hot work permit
85
As an alternate to the water-filling method fill the container with an
inert gas. Flammable gases and vapors will be rendered nonflammable and nonexplosive if mixed with a sufficient amount of inert
gas. Nitrogen or carbon dioxide is normally used. The concentration of flammable gases and vapors must be checked by testing.
The inert gas concentration must be maintained during the entire
welding and cutting operation. Hot work or welding permits should
be utilized for all welding or cutting operations on containers that
have held hazardous materials.
Welding on Containers
Any container or hollow body such as a can, tank, hollow compartment in a weldment, or hollow area in a casting, even though
it may contain only air, must be given special attention before
welding. No container shall be presumed to be clean or safe,
but containers can be made safe for hot work. The heat from
welding can cause trapped gas to expand. The expansion can
create dangerously high pressure so that the part or container
may explode. Always vent containers before welding or cutting.
Hollow areas may also contain gases that are extremely dangerous when heated or exposed to an arc or flame. Therefore, drill
or pierce a path into the hollow space to provide pressure relief.
Hot Tapping
In pipe lines, welders sometimes do hot tapping. This is the
welding of a special fitting to a line carrying a combustible liquid
or gas and then cutting a hole in the pipe after the fitting has been
welded to it. This must be done only by experienced people using
special equipment with proper precautions. Refer to the American
Petroleum Institute (API) publication, Safe Hot Tapping Practices
in the Petroleum and Petro-chemical Industries.(27)
Explosions and fires may result if welding or cutting is done on
empty containers that are not entirely free of combustible reactive
or toxic solids, liquids, vapors, dust, and gases. Cracks and
crevices, as well as hidden joints, can contain hazardous materials.
Containers can be made safe for welding or cutting by following
prescribed steps. Refer to the American Welding Society’s Safe
Practices for the Preparation of Containers and Piping for Welding
and Cutting.(26) No container should be considered clean or safe
until proven so by tests.
6. Compressed Gases
All compressed gas cylinders are potential hazards. One of the
major hazards is the possibility of sudden release of the gas by
removal or breaking off of the valve. The Compressed Gas Association (CGA) (Pamphlet V-1)has established a 0.300 inch (7.62
mm) maximum valve inlet diameter as a requirement to minimize
the propulsion effect in case the valve is severed. Cylinders
meeting the CGA requirements will rapidly release all of their gas
which could be a health and/or a flammability concern. The gas
release can cause a whistling sound and possibly spin the cylinder
uncontrollably. Larger valve openings, such as those for propane,
butane, or fire protection cylinders, may cause the cylinder to take
off and become airborne.
Cleaning the container, which is normally made of metal, is necessary in all cases before welding or cutting. Cleaning should be done
by experienced personnel familiar with the characteristics of the
contents. Cleaning should be done outdoors. If this is impractical,
the inside work area should be well ventilated so that hazardous
vapors will be quickly carried away. Identify the material that was
in the container and match the cleaning method to the material
previously contained. Only a qualified person should designate
and manage the cleaning process. No cleaning method is perfect,
and after cleaning, the container should be inspected to determine
that it is thoroughly cleaned.
When it is determined that the container is safe the container
should be so marked, signed, and dated. Even after tanks have
been made safe they can be filled with water as an added precaution before welding or cutting. Place the container so that it can
be kept filled with water to within a few inches of the point where
welding and cutting are to be done. Make sure that the space
above the water level is vented so that the heated air can escape,
as shown in Figure 20.
Treatment of Gas Cylinders
Gases used for welding, fuel gases, oxygen, or shielding gases,
are normally delivered in cylinders which are manufactured and
maintained by the gas supplier in accordance with the regulations
of the U.S. Department of Transportation (DOT). In Canada the
Board of Transport Commissioners for Canada has this responsibility. In most countries there are laws and regulations concerning
manufacturing, maintaining, and periodic inspection of portable
cylinders for the storage and shipment of compressed gases. All
compressed gas cylinders must be legibly marked to identify the
gases contained by either the chemical or the trade name of the
gas. There is no international uniform color coding for identification
purposes, however some countries have standardized color marking systems. For additional information, refer to American Welding
Society’s Safety and Health Fact Sheet No. 30, “Cylinders: Safe
Storage, Handling, and Use”.(28) Always inspect cylinders for any
damage and report this damage to your gas supplier.
Vent
Water
Cylinder Storage
Oxygen cylinders should be stored separately from fuel gas cylinders and separate from combustible materials. Store cylinders in
cool, well-ventilated areas. The temperature of the cylinder should
never be allowed to exceed 125°F (52°C). Cylinders should be
stored vertically and secured to prevent falling. The valve protection caps must be in place. When cylinders are empty they should
be marked “Empty” and the valves must be closed to prevent
contamination from entering. When the gas cylinders are in use,
a regulator is attached and the cylinder should be secured by
means of chains or clamps. Cylinders for portable apparatus
should be securely mounted in specially designed cylinder
trucks. Cylinders should be handled with respect. They should
Figure 20 - Safe way to weld a container
that held combustibles
86
not be dropped or struck. They should never be used as rollers.
Hammers or wrenches should not be used to open cylinder valves
that are fitted with hand wheels. They should never be moved
by electromagnetic cranes. They should never be in an electric
circuit so that the welding current could pass through them. An
arc strike on a cylinder will damage the cylinder causing possible
fracture, and requiring the cylinder to be condemned and taken
out of service.
The slag that often covers the deposited weld metal must usually be removed. Welds are often chipped and ground. Hand
and power tools are employed and the materials removed are
propelled through the air to become potential projectile or fire
hazards. Safety glasses with side shields should be worn under
the welding helmet.
Oxygen
Radioactive Hot Areas
Oxygen is one of the most common gases carried in portable
high-pressure cylinders. It should always be labelled “oxygen”,
never “air”. Combustibles should be kept away from oxygen,
including the cylinder, valves, regulators, and hose apparatus.
Oxygen cylinders or oxygen apparatus should not be handled with
oily hands or oily gloves. Oxygen does not burn, but will support
and vigorously accelerate combustion of oil and grease and other
flammable materials, causing them to burn with great intensity. Oil
or grease in the presence of oxygen may spontaneously ignite and
violently burn or explode. Oxygen should never be used in any air
tools or for any of the purposes where compressed air is normally
used. Escaping oxygen can enrich the work area, especially enclosed areas, and can create a fire or explosion hazard.
Welders may be required to work in radioactive “hot” areas. This
is due to repair and maintenance operations necessary in nuclear
power plants. In such cases, extra special care and precaution
must be taken to determine the radiation levels, time of exposure,
radiation protection, and all other factors involved. The exposure
time may be extremely short and welders may be used to set up
automated welding devices and then leave the hot area to operate
the devices remotely. Only qualified personnel with knowledge of
working in and around radioactive areas should be permitted to
make judgments of this type.
7. Weld Cleaning and Other Hazards
Noise
Weld chipping and weld peening produce excessive noise and
should be controlled. Excessive noise can damage hearing and
cause other injury. Noise exposure can cause either temporary
or permanent hearing loss. OSHA regulations prescribe allowable noise exposure levels. Carbon arc gouging at high currents
produces high noise levels and ear protection is required. Plasma
arc cutting with high current also creates excessive noise and ear
protection is required. Figure 21 shows a worker wearing suitable
protection for noisy work. Noise measurement instruments are
available and should be used to check noise in the work area
so that precautionary measures can be taken. Normal arc weld
operations do not exceed noise level requirements as specified
by OSHA. In combination with other noise producing machinery,
noise levels may be excessive. Noise levels can be measured and
monitored by means of specialized instruments. The American
Welding Society’s Arc Welding and Cutting Noise (AWN)(29) should
be consulted. It is necessary that trained personnel be used to
measure noise. You can request help from your company’s safety
department or from the State Industrial Commission representatives. Noise levels are reduced fairly rapidly as the worker moves
further away from the source of the noise.
Fuel Gases
There are a number of fuel gases. All are compounds of carbon
and hydrogen. All fuel gases are potentially hazardous and should
be treated with respect.
When welding or cutting with oxygen and fuel gases the welder
should be particularly alert to backfires, sustained backfires, and
flashbacks. A backfire is a a momentary recession of the flame into
the torch, potentially causing a flashback or sustained backfire. It
is usually signaled by a popping sound, after which the flame may
either extinguish or reignite at the end of the tip. This is caused by
an obstruction of the gas flow or by an overheated or damaged
tip. If this occurs the equipment should be shut down immediately
and corrective action taken. A sustained backfire is the recession
of the flame into the torch body with continued burning characterized by an initial popping sound followed by a squealing or hissing
sound, potentially burning through the torch body. A flashback
is the recession of the flame through the torch and into the hose,
regulator, and/or cylinder, potentially causing an explosion. When
this occurs, the equipment should be shut down immediately and
corrective action should be taken. Some causes of flashback
include improper pressures, distorted or loose tips, clogged or
damaged tips, damaged seats and kinked hoses.
In extinguishing the oxygen fuel gas flame one recommended
sequence is to first close the torch oxygen valve and then the
torch acetylene or fuel gas valve. Some equipment manufacturers
recommend closing the fuel gas valve first. In any case, follow the
procedure recommended by the torch manufacturer. In starting a
torch, it is usually recommended to first open the fuel gas valve
slilghtly and, with a spark lighter, light the torch followed by opening
the oxygen torch valve. Always read, understand and follow the
recommendations of the equipment manufacturer.
Shielding Gases
Shielding gases are either inert or active. Typical inert gases
are argon and helium and are stored in high-pressure cylinders.
Nitrogen, considered inert in some cases, is also stored in high
pressure cylinders. These cylinders must be treated with the same
precautions as oxygen cylinders. The active gas normally used
for weld shielding is carbon dioxide (CO 2).
Courtesy of Occupational Safety and Health Administration, Washington, DC.
Figure 21 - Worker wearing suitable ear protection for noisy work.
87
Other Hazards
Adequate mechanical ventilation should be provided for all automated brazing and soldering operations to remove explosive
or toxic gases. In addition, large quantities of liquid heated flux or
filler metal creates hazards. Guards on motion devices must be
properly designed and always in place.
Falling items create hazards. Hard hats should be worn in connection with welding helmets on construction sites and in some
plants. Other hazards such as falling from high places, working
with heavy objects, and working around heated metals are similar
to the hazards encountered by all employees in plants, forging
shops, structural shops, and so on. Welding electrode stubs act
as rollers when stepped on at the wrong angle. Electrode stubs
should be placed in containers and not thrown on the floor or
working surface where others can step on them.
The American Welding Society has many documents related to
brazing and soldering. For some safety information, refer to “Braze
Safely” (44) (BRS) and the “Brazing Handbook 45 (BRH). Also refer
to the “Soldering Handbook” (46) (SHB).
Resistance welding operations involve some potential hazards.
These are largely involved with motion since it is present with resistance welding equipment. Dual palm buttons are normally used
to provide operator safety. Operators should wear face shields,
safety glasses or goggles to protect the face and eyes from flying
sparks that may be ejected from the weld area.
8. Safety for Specific Welding
Processes and Occupations
For further reference, consult the “Resistance Welding Manual,”(47)
(RWM) and “Recommended Practices for Resistance Welding,”(48)
C1.1, available from the American Welding Society.
Arc air cutting and gouging and plasma arc cutting at high
currents creates noise of a level that may be harmful. Ear protection
should be worn. Refer to American Welding Society’s “Recommended Practices for Air Carbon Arc Gouging and Cutting,”(49)
(C5.3) and “Recommended Practices fo Plasma Arc Cutting and
Gouging,”(50) (C5.2).
Electron beam welding is an automated process but the motion is normally enclosed. In most cases a vacuum is involved
with the welding chamber and normal precautions are required. In
the high-voltage electron beam systems, x-rays are generated as
electron beam strikes the work piece. Adequate shielding must be
provided to protect the operator from x-rays. Refer to American
Welding Society’s “Recommended Practices for Electron Beam
Welding,”(51) (C7.1).
The previous sections dealt primarily with arc welding and oxyfuel gas welding, cutting and torch brazing. The other welding
and allied processes can be hazardous if safety precautions are
ignored. The potential hazards mentioned previously apply to most
welding and allied processes since electricity, compressed gases,
flames, heated metals or fumes are usually involved. Specific process applications or welding occupations involve other hazards.
The following is an overview of some safety situations.
Underwater welding is one of the most hazardous welding
occupations. Underwater work of any type is hazardous at any
working depth. Welding in the dry, underwater, is welding in an
atmosphere which is under pressure that is greater than sea level
atmosphere pressure. Higher operating pressures create special
hazards. The hazards of underwater welding in the wet in contact
with the water or in a habitat are very complex and are only briefly
mentioned here. More complete information concerning aspects of
underwater welding are provided in the U.S. Navy’s “Underwater
Cutting and Welding” technical manual.(38) Also refer to American
Welding Society’s D3.6M “Specification for Underwater Welding.” (41)
Robotic and automated welding are becoming more popular.
Robot welding combines the potential hazards of welding with
the hazards of moving metal working machinery. Robots operate outside their machine base area. They involve unanticipated
motion, may start unexpectedly, and operate at relatively high
rates of speed. Robots are normally safe since operators work
outside the operating envelope of the robot. However, when
programming robots or maintaining equipment, or troubleshooting
welding problems, people work in close proximity to the robot’s
welding torch and are thus exposed to potential hazards.
Thermal spraying involves potential hazards in addition to those
involved with arc welding and oxy-fuel gas welding. These involve
the use of powders or wires which are atomized and sprayed on
the workpiece. Large amounts of particulate matter are produced,
which can create problems. For further reference, see American
Welding Society’s “Thermal Spray Manual,”(52) (TSM) and “Thermal
Spraying Practice, Theory and Application,”(53) (TSS).
Laser welding is usually an automated operation. Lasers
are used not only for welding but also for cutting and surface
metal treatment. The equipment must definitely be installed in
accordance with the manufacturer’s recommendations. Certain
classes of lasers generate radiation which can produce eye damage. This also relates to reflected laser light. Safety precautions
require the use of special glasses and other protective materials.
Helpful information can be found in American Welding Society’s
“Recommended Practices for Laser Beam Welding, Cutting, and
Drilling,”(54) (C7.2).
The American Welding Society has several documents related to
robotic welding. For safety information, refer to D 16.1, “Specification for Robotic Arc Welding Safety,” (42) and D16.3, “Risk Assessment Guide for Robotic Arc Welding.” (43)
Allied Processes
Automated brazing and soldering involves moving equipment
with the associated hazards. However fluxes and filler metals employed may give off noxious fumes when heated, especially when
heated to temperatures normally above operating temperatures.
Continued attention to safe practice is required for all welding,
cutting and allied processes. Common sense and the adoption
of practices recommended in this book will help provide a safe
workplace.
88
REMEMBER
safety is simple as,
Always
Be
Careful
89
INTERNATIONAL STANDARDS
90
TABLE OF CONTENTS
SECTION 1 − SAFETY PRECAUTIONS - READ BEFORE USING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-1. Symbol Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-2. Arc Welding Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-3. Additional Symbols For Installation, Operation, And Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-4. California Proposition 65 Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-5. Principal Safety Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1-6. EMF Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 2 − GAS METAL ARC WELDING (GMAW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-1. Typical GMAW Semiautomatic Setup With Constant Speed Feeder . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-2. Typical GMAW Semiautomatic Setup With Voltage-Sensing Feeder . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-3. Typical GMAW Process Control Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-4. Holding And Positioning Welding Gun . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-5. Conditions That Affect Weld Bead Shape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-6. Gun Movement During Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-7. Poor Weld Bead Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-8. Good Weld Bead Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2-9. Common GMAW Shielding Gases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 3 − MODES OF GMAW TRANSFER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-1. Short Circuit Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-2. Globular Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-3. Spray Arc Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SECTION 4 − GMAW WELDING TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-1. Excessive Spatter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-2. Porosity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-3. Incomplete Fusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-4. Excessive Penetration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-5. Lack Of Penetration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-6. Burn Through . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-7. Waviness Of Bead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4-8. Distortion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
91
SECTION 1 − SAFETY PRECAUTIONS - READ BEFORE USING
som 2011−10
7
Protect yourself and others from injury — read, follow, and save these important safety precautions and operating instructions.
1-1. Symbol Usage
DANGER! − Indicates a hazardous situation which, if
not avoided, will result in death or serious injury. The
possible hazards are shown in the adjoining symbols
or explained in the text.
. Indicates special instructions.
Indicates a hazardous situation which, if not avoided,
could result in death or serious injury. The possible
hazards are shown in the adjoining symbols or explained in the text.
This group of symbols means Warning! Watch Out! ELECTRIC
SHOCK, MOVING PARTS, and HOT PARTS hazards. Consult symbols and related instructions below for necessary actions to avoid the
hazards.
NOTICE − Indicates statements not related to personal injury.
1-2. Arc Welding Hazards
D Always verify the supply ground − check and be sure that input
power cord ground wire is properly connected to ground terminal in
disconnect box or that cord plug is connected to a properly
grounded receptacle outlet.
The symbols shown below are used throughout this manual
to call attention to and identify possible hazards. When you
see the symbol, watch out, and follow the related instructions
to avoid the hazard. The safety information given below is
only a summary of the more complete safety information
found in the Safety Standards listed in Section 1-5. Read and
follow all Safety Standards.
D When making input connections, attach proper grounding conductor first − double-check connections.
D Keep cords dry, free of oil and grease, and protected from hot metal
and sparks.
Only qualified persons should install, operate, maintain, and
repair this unit.
D Frequently inspect input power cord for damage or bare wiring −
replace cord immediately if damaged − bare wiring can kill.
D Turn off all equipment when not in use.
During operation, keep everybody, especially children, away.
D Do not use worn, damaged, undersized, or poorly spliced cables.
D Do not drape cables over your body.
ELECTRIC SHOCK can kill.
D If earth grounding of the workpiece is required, ground it directly
with a separate cable.
Touching live electrical parts can cause fatal shocks
or severe burns. The electrode and work circuit is
electrically live whenever the output is on. The input
power circuit and machine internal circuits are also
live when power is on. In semiautomatic or automatic
wire welding, the wire, wire reel, drive roll housing,
and all metal parts touching the welding wire are
electrically live. Incorrectly installed or improperly
grounded equipment is a hazard.
D Do not touch electrode if you are in contact with the work, ground,
or another electrode from a different machine.
D Do not touch electrode holders connected to two welding machines at the same time since double open-circuit voltage will be
present.
D Use only well-maintained equipment. Repair or replace damaged
parts at once. Maintain unit according to manual.
D Do not touch live electrical parts.
D Wear dry, hole-free insulating gloves and body protection.
D Insulate yourself from work and ground using dry insulating mats
or covers big enough to prevent any physical contact with the work
or ground.
D Do not use AC output in damp areas, if movement is confined, or if
there is a danger of falling.
D Use AC output ONLY if required for the welding process.
D If AC output is required, use remote output control if present on
unit.
D Additional safety precautions are required when any of the following electrically hazardous conditions are present: in damp
locations or while wearing wet clothing; on metal structures such
as floors, gratings, or scaffolds; when in cramped positions such
as sitting, kneeling, or lying; or when there is a high risk of unavoidable or accidental contact with the workpiece or ground. For these
conditions, use the following equipment in order presented: 1) a
semiautomatic DC constant voltage (wire) welder, 2) a DC manual
(stick) welder, or 3) an AC welder with reduced open-circuit voltage. In most situations, use of a DC, constant voltage wire welder
is recommended. And, do not work alone!
D Disconnect input power or stop engine before installing or
servicing this equipment. Lockout/tagout input power according to
OSHA 29 CFR 1910.147 (see Safety Standards).
D Wear a safety harness if working above floor level.
D Keep all panels and covers securely in place.
D Clamp work cable with good metal-to-metal contact to workpiece
or worktable as near the weld as practical.
D Insulate work clamp when not connected to workpiece to prevent
contact with any metal object.
D Do not connect more than one electrode or work cable to any
single weld output terminal. Disconnect cable for process not in
use.
SIGNIFICANT DC VOLTAGE exists in inverter welding power sources AFTER removal of input power.
D Turn Off inverter, disconnect input power, and discharge input
capacitors according to instructions in Maintenance Section
before touching any parts.
HOT PARTS can burn.
D Do not touch hot parts bare handed.
D Allow cooling period before working on equipment.
D To handle hot parts, use proper tools and/or
wear heavy, insulated welding gloves and
clothing to prevent burns.
D Properly install, ground, and operate this equipment according to
its Owner’s Manual and national, state, and local codes.
92
D Remove stick electrode from holder or cut off welding wire at
contact tip when not in use.
FUMES AND GASES can be hazardous.
D Wear oil-free protective garments such as leather gloves, heavy
shirt, cuffless trousers, high shoes, and a cap.
Welding produces fumes and gases. Breathing
these fumes and gases can be hazardous to your
health.
D Remove any combustibles, such as a butane lighter or matches,
from your person before doing any welding.
D Keep your head out of the fumes. Do not breathe the fumes.
D If inside, ventilate the area and/or use local forced ventilation at the
arc to remove welding fumes and gases.
D If ventilation is poor, wear an approved air-supplied respirator.
D Read and understand the Material Safety Data Sheets (MSDSs)
and the manufacturer’s instructions for metals, consumables,
coatings, cleaners, and degreasers.
D Work in a confined space only if it is well ventilated, or while
wearing an air-supplied respirator. Always have a trained watchperson nearby. Welding fumes and gases can displace air and
lower the oxygen level causing injury or death. Be sure the breathing air is safe.
D Do not weld in locations near degreasing, cleaning, or spraying operations. The heat and rays of the arc can react with vapors to form
highly toxic and irritating gases.
D Do not weld on coated metals, such as galvanized, lead, or
cadmium plated steel, unless the coating is removed from the weld
area, the area is well ventilated, and while wearing an air-supplied
respirator. The coatings and any metals containing these elements
can give off toxic fumes if welded.
D After completion of work, inspect area to ensure it is free of sparks,
glowing embers, and flames.
D Use only correct fuses or circuit breakers. Do not oversize or bypass them.
D Follow requirements in OSHA 1910.252 (a) (2) (iv) and NFPA 51B
for hot work and have a fire watcher and extinguisher nearby.
FLYING METAL or DIRT can injure eyes.
D Welding, chipping, wire brushing, and grinding
cause sparks and flying metal. As welds cool,
they can throw off slag.
D Wear approved safety glasses with side
shields even under your welding helmet.
BUILDUP OF GAS can injure or kill.
D Shut off compressed gas supply when not in use.
D Always ventilate confined spaces or use
approved air-supplied respirator.
ARC RAYS can burn eyes and skin.
Arc rays from the welding process produce intense
visible and invisible (ultraviolet and infrared) rays
that can burn eyes and skin. Sparks fly off from the
weld.
ELECTRIC AND MAGNETIC FIELDS (EMF)
can affect Implanted Medical Devices.
D Wearers of Pacemakers and other Implanted
Medical Devices should keep away.
D Wear an approved welding helmet fitted with a proper shade of
filter lenses to protect your face and eyes from arc rays and
sparks when welding or watching (see ANSI Z49.1 and Z87.1
listed in Safety Standards).
D Wear approved safety glasses with side shields under your
helmet.
D Use protective screens or barriers to protect others from flash,
glare and sparks; warn others not to watch the arc.
D Implanted Medical Device wearers should consult their doctor
and the device manufacturer before going near arc welding, spot
welding, gouging, plasma arc cutting, or induction heating
operations.
NOISE can damage hearing.
D Wear protective clothing made from durable, flame-resistant
material (leather, heavy cotton, or wool) and foot protection.
Noise from some processes or equipment can
damage hearing.
WELDING can cause fire or explosion.
D Wear approved ear protection if noise level is
high.
Welding on closed containers, such as tanks,
drums, or pipes, can cause them to blow up. Sparks
can fly off from the welding arc. The flying sparks, hot
workpiece, and hot equipment can cause fires and
burns. Accidental contact of electrode to metal objects can cause
sparks, explosion, overheating, or fire. Check and be sure the area is
safe before doing any welding.
D Remove all flammables within 35 ft (10.7 m) of the welding arc. If
this is not possible, tightly cover them with approved covers.
D Do not weld where flying sparks can strike flammable material.
D Protect yourself and others from flying sparks and hot metal.
D Be alert that welding sparks and hot materials from welding can
easily go through small cracks and openings to adjacent areas.
D Watch for fire, and keep a fire extinguisher nearby.
D Be aware that welding on a ceiling, floor, bulkhead, or partition can
cause fire on the hidden side.
D Do not weld on containers that have held combustibles, or on
closed containers such as tanks, drums, or pipes unless they are
properly prepared according to AWS F4.1 and AWS A6.0 (see
Safety Standards).
D Do not weld where the atmosphere may contain flammable dust,
gas, or liquid vapors (such as gasoline).
D Connect work cable to the work as close to the welding area as
practical to prevent welding current from traveling long, possibly
unknown paths and causing electric shock, sparks, and fire
hazards.
D Do not use welder to thaw frozen pipes.
154 557 Page 2
CYLINDERS can explode if damaged.
Compressed gas cylinders contain gas under high
pressure. If damaged, a cylinder can explode. Since
gas cylinders are normally part of the welding
process, be sure to treat them carefully.
D Protect compressed gas cylinders from excessive heat, mechanical shocks, physical damage, slag, open flames, sparks, and arcs.
D Install cylinders in an upright position by securing to a stationary
support or cylinder rack to prevent falling or tipping.
D Keep cylinders away from any welding or other electrical circuits.
D Never drape a welding torch over a gas cylinder.
D Never allow a welding electrode to touch any cylinder.
D Never weld on a pressurized cylinder − explosion will result.
D Use only correct compressed gas cylinders, regulators, hoses,
and fittings designed for the specific application; maintain them
and associated parts in good condition.
D Turn face away from valve outlet when opening cylinder valve.
D Keep protective cap in place over valve except when cylinder is in
use or connected for use.
D Use the right equipment, correct procedures, and sufficient number of persons to lift and move cylinders.
D Read and follow instructions on compressed gas cylinders,
associated equipment, and Compressed Gas Association (CGA)
publication P-1 listed in Safety Standards.
93
1-3. Additional Symbols For Installation, Operation, And Maintenance
FIRE OR EXPLOSION hazard.
BATTERY EXPLOSION can injure.
D Do not install or place unit on, over, or near
combustible surfaces.
D Do not install unit near flammables.
D Do not overload building wiring − be sure power supply system is
properly sized, rated, and protected to handle this unit.
D Do not use welder to charge batteries or jump
start vehicles unless it has a battery charging
feature designed for this purpose.
MOVING PARTS can injure.
D Keep away from moving parts such as fans.
D Keep all doors, panels, covers, and guards
closed and securely in place.
FALLING EQUIPMENT can injure.
D Use lifting eye to lift unit only, NOT running
gear, gas cylinders, or any other accessories.
D Use equipment of adequate capacity to lift and
support unit.
D Have only qualified persons remove doors, panels, covers, or
guards for maintenance and troubleshooting as necessary.
D Reinstall doors, panels, covers, or guards when maintenance is
finished and before reconnecting input power.
D If using lift forks to move unit, be sure forks are long enough to
extend beyond opposite side of unit.
D Keep equipment (cables and cords) away from moving vehicles
when working from an aerial location.
D Follow the guidelines in the Applications Manual for the Revised
NIOSH Lifting Equation (Publication No. 94−110) when manually lifting heavy parts or equipment.
READ INSTRUCTIONS.
D Read and follow all labels and the Owner’s
Manual carefully before installing, operating, or
servicing unit. Read the safety information at
the beginning of the manual and in each
section.
D Use only genuine replacement parts from the manufacturer.
D Perform maintenance and service according to the Owner’s
Manuals, industry standards, and national, state, and local
codes.
OVERUSE can cause OVERHEATING
D Allow cooling period; follow rated duty cycle.
D Reduce current or reduce duty cycle before
starting to weld again.
D Do not block or filter airflow to unit.
H.F. RADIATION can cause interference.
FLYING SPARKS can injure.
D Wear a face shield to protect eyes and face.
D Shape tungsten electrode only on grinder with
proper guards in a safe location wearing proper
face, hand, and body protection.
D
D Sparks can cause fires — keep flammables away.
D
D
D
STATIC (ESD) can damage PC boards.
D Put on grounded wrist strap BEFORE handling
boards or parts.
D Use proper static-proof bags and boxes to
store, move, or ship PC boards.
D High-frequency (H.F.) can interfere with radio
navigation, safety services, computers, and
communications equipment.
D Have only qualified persons familiar with
electronic equipment perform this installation.
The user is responsible for having a qualified electrician promptly correct any interference problem resulting from the installation.
If notified by the FCC about interference, stop using the
equipment at once.
Have the installation regularly checked and maintained.
Keep high-frequency source doors and panels tightly shut, keep
spark gaps at correct setting, and use grounding and shielding to
minimize the possibility of interference.
ARC WELDING can cause interference.
MOVING PARTS can injure.
D Keep away from moving parts.
D Keep away from pinch points such as drive
rolls.
D
WELDING WIRE can injure.
D
D Do not press gun trigger until instructed to do
so.
D Do not point gun toward any part of the body,
other people, or any metal when threading
welding wire.
D
D
94
D Electromagnetic energy can interfere with
sensitive electronic equipment such as
computers and computer-driven equipment
such as robots.
D Be sure all equipment in the welding area is
electromagnetically compatible.
To reduce possible interference, keep weld cables as short as
possible, close together, and down low, such as on the floor.
Locate welding operation 100 meters from any sensitive electronic equipment.
Be sure this welding machine is installed and grounded
according to this manual.
If interference still occurs, the user must take extra measures
such as moving the welding machine, using shielded cables,
using line filters, or shielding the work area.
1-4. California Proposition 65 Warnings
Welding or cutting equipment produces fumes or gases
which contain chemicals known to the State of California to
cause birth defects and, in some cases, cancer. (California
Health & Safety Code Section 25249.5 et seq.)
This product contains chemicals, including lead, known to
the state of California to cause cancer, birth defects, or other
reproductive harm. Wash hands after use.
1-5. Principal Safety Standards
Safety in Welding, Cutting, and Allied Processes, ANSI Standard Z49.1,
is available as a free download from the American Welding Society at
http://www.aws.org or purchased from Global Engineering Documents
(phone: 1-877-413-5184, website: www.global.ihs.com).
Safe Practices for the Preparation of Containers and Piping for Welding
and Cutting, American Welding Society Standard AWS F4.1, from Global Engineering Documents (phone: 1-877-413-5184, website:
www.global.ihs.com).
Safe Practices for Welding and Cutting Containers that have Held Combustibles, American Welding Society Standard AWS A6.0, from Global
Engineering Documents (phone: 1-877-413-5184,
website: www.global.ihs.com).
National Electrical Code, NFPA Standard 70, from National Fire Protection Association, Quincy, MA 02269 (phone: 1-800-344-3555, website:
www.nfpa.org and www. sparky.org).
Safe Handling of Compressed Gases in Cylinders, CGA Pamphlet P-1,
from Compressed Gas Association, 14501 George Carter Way, Suite
103, Chantilly, VA 20151 (phone: 703-788-2700, website:www.cganet.com).
Safety in Welding, Cutting, and Allied Processes, CSA Standard
W117.2, from Canadian Standards Association, Standards Sales, 5060
Spectrum Way, Suite 100, Ontario, Canada L4W 5NS (phone:
800-463-6727, website: www.csa-international.org).
Safe Practice For Occupational And Educational Eye And Face Protection, ANSI Standard Z87.1, from American National Standards Institute,
25 West 43rd Street, New York, NY 10036 (phone: 212-642-4900, website: www.ansi.org).
Standard for Fire Prevention During Welding, Cutting, and Other Hot
Work, NFPA Standard 51B, from National Fire Protection Association,
Quincy, MA 02269 (phone: 1-800-344-3555, website: www.nfpa.org.
OSHA, Occupational Safety and Health Standards for General Industry, Title 29, Code of Federal Regulations (CFR), Part 1910, Subpart Q,
and Part 1926, Subpart J, from U.S. Government Printing Office, Superintendent of Documents, P.O. Box 371954, Pittsburgh, PA 15250-7954
(phone: 1-866-512-1800) (there are 10 OSHA Regional Offices—
phone for Region 5, Chicago, is 312-353-2220, website:
www.osha.gov).
Applications Manual for the Revised NIOSH Lifting Equation, The National Institute for Occupational Safety and Health (NIOSH), 1600
Clifton Rd, Atlanta, GA 30333 (phone: 1-800-232-4636, website:
www.cdc.gov/NIOSH).
1-6. EMF Information
Electric current flowing through any conductor causes localized electric
and magnetic fields (EMF). Welding current creates an EMF field
around the welding circuit and welding equipment. EMF fields may interfere with some medical implants, e.g. pacemakers. Protective
measures for persons wearing medical implants have to be taken. For
example, restrict access for passers−by or conduct individual risk assessment for welders. All welders should use the following procedures
in order to minimize exposure to EMF fields from the welding circuit:
4. Keep head and trunk as far away from the equipment in the
welding circuit as possible.
5. Connect work clamp to workpiece as close to the weld as
possible.
6. Do not work next to, sit or lean on the welding power source.
7. Do not weld whilst carrying the welding power source or wire
feeder.
1. Keep cables close together by twisting or taping them, or using a
cable cover.
About Implanted Medical Devices:
Implanted Medical Device wearers should consult their doctor and the
device manufacturer before performing or going near arc welding, spot
welding, gouging, plasma arc cutting, or induction heating operations.
If cleared by your doctor, then following the above procedures is recommended.
2. Do not place your body between welding cables. Arrange cables
to one side and away from the operator.
3. Do not coil or drape cables around your body.
95
SECTION 2 − GAS METAL ARC WELDING (GMAW)
Gas Metal Arc Welding (GMAW) is a welding process which joins metals by heating the metals to their melting point
with an electric arc. The arc is between a continuous, consumable electrode wire and the metal being welded. The
arc is shielded from contaminants in the atmosphere by a shielding gas.
GMAW can be done in three different ways:
S Semiautomatic Welding - equipment controls only the electrode wire feeding. Movement of welding gun is controlled
by hand. This may be called hand-held welding.
S Machine Welding - uses a gun that is connected to a manipulator of some kind (not hand-held). An operator has
to constantly set and adjust controls that move the manipulator.
S Automatic Welding - uses equipment which welds without the constant adjusting of controls by a welder or operator.
On some equipment, automatic sensing devices control the correct gun alignment in a weld joint.
Basic equipment for a typical GMAW semiautomatic setup:
S Welding Power Source - provides welding power.
S Wire Feeders (Constant Speed And Voltage-Sensing) - controls supply of wire to welding gun.
Constant Speed Feeder - Used only with a constant voltage (CV) power source. This type of feeder has a control
cable that will connect to the power source. The control cable supplies power to the feeder and allows the capability
of remote voltage control with certain power source/feeder combinations. The wire feed speed (WFS) is set on the
feeder and will always be constant for a given preset value.
Voltage-Sensing Feeder - Can be used with either a constant voltage (CV) or constant current (CC) - direct current
(DC) power source. This type of feeder is powered off of the arc voltage and does not have a control cord. When
set to (CV), the feeder is similar to a constant speed feeder. When set to (CC), the wire feed speed depends on
the voltage present. The feeder changes the wire feed speed as the voltage changes. A voltage sensing feeder
does not have the capability of remote voltage control.
S Supply of Electrode Wire.
S Welding Gun - delivers electrode wire and shielding gas to the weld puddle.
S Shielding Gas Cylinder - provides a supply of shielding gas to the arc.
96
2-1. Typical GMAW Semiautomatic Setup With Constant Speed Feeder
1
Constant Voltage (CV)
Welding Power Source
2
Contactor Control/Power Cord
3
Weld Cable To Feeder
4
Ground Cable To Workpiece
5
Workpiece
6
Welding Gun
7
Constant Speed Wire Feeder
8
Electrode Wire
9
Gas Hose
10 Shielding Gas Cylinder
1
10
2
3
4
5
8
9
7
6
804 656-A
97
2-2. Typical GMAW Semiautomatic Setup With Voltage-Sensing Feeder
1
Constant Current (CC-DC) Or
Constant Voltage (CV)
Welding Power Source
2
Weld Cable To Feeder
3
Ground Cable To Workpiece
4
Workpiece
5
Voltage-Sensing Clamp
6
Welding Gun
7
Gun Trigger Receptacle
8
Voltage-Sensing Wire Feeder
9
Gas Hose
10 Shielding Gas Cylinder
1
10
2
9
8
3
7
4
5
6
Ref. 804 000-C
98
2-3. Typical GMAW Process Control Settings
. These settings are guidelines only. Material
and wire type, joint design, fit−up, position,
shielding gas, etc. affect settings. Test welds
to be sure they comply to specifications.
1
1
1/8 or
.125 in.
Convert Material Thickness to
Amperage (A)
(.001 in. = 1 ampere)
.125 = 125 A
. Material thickness determines weld
parameters.
2
2
3
Select Wire Size
Wire Size
Amperage Range
.030 in.
.035 in.
.045 in.
40 − 145 A
50 − 180 A
75 − 250 A
Select Wire Speed (Amperage)
125 A based on 1/8 in. (3 mm) material thickness.
(ipm = inch per minute)
Wire
Size
Suggested
Wire Speed
(Approx.)
.030 in. 2 in. per amp 2 x 125 A = 250 IPM
.035 in. 1.6 in. per amp 1.6 x 125 A = 200 IPM
.045 in. 1 in. per amp 1 x 125 A = 125 IPM
. Wire speed (amperage) controls weld pene-
3
tration (wire speed = burn-off rate).
4
4
Select Voltage
Low Voltage: wire stubs into work
High Voltage: arc is unstable (spatter)
Set voltage midway between high/low voltage.
. Voltage controls height and width of weld
bead.
802 806-A / 800 354
99
2-4. Holding And Positioning Welding Gun
. Welding wire is energized when
gun trigger is pressed. Before
lowering helmet and pressing
trigger, be sure wire is no more
than 1/2 in. (13 mm) past end of
nozzle, and tip of wire is positioned correctly on seam.
1
3
2
1
Hold Gun And Control Gun
Trigger
2
Workpiece
3
Work Clamp
4
Electrode Extension (Stickout)
1/4 To 1/2 in. (6 To 13 mm)
5
Cradle Gun And Rest Hand On
Workpiece
5
Groove Welds
6
End View Of Work Angle
7
Side View Of Gun Angle
Fillet Welds
4
8
End View Of Work Angle
9
Side View Of Gun Angle
0-15
6
90
90
7
0-15
45
8
45
9
S-0421-A
100
2-5. Conditions That Affect Weld Bead Shape
. Weld bead shape depends on
gun angle, direction of travel,
electrode extension (stickout),
travel speed, thickness of base
metal, wire feed speed (weld
current), and voltage.
1
Gun Angles And Weld Bead
Profiles
10
1
Push
2
Perpendicular
3
Drag
Electrode Extensions (Stickout)
2
3
10
4
Short
5
Normal
6
Long
Fillet Weld Electrode Extension
(Stickout)
7
Short
8
Normal
9
Long
Gun Travel Speed
10 Slow
11 Normal
5
4
7
10
6
9
8
11
12 Fast
12
S-0634-A
101
2-6. Gun Movement During Welding
. Normally, a single stringer bead
1
is satisfactory for most narrow
groove weld joints. However, for
wide groove weld joints or bridging across gaps, a weave bead
or multiple stringer beads works
better.
2
1
Stringer Bead − Steady Movement Along Seam
2
Weave Bead − Side To Side
Movement Along Seam
3
Weave Patterns
Use weave patterns to cover a wide
area in one pass of the electrode.
3
S-0054-A
2-7. Poor Weld Bead Characteristics
1
Large Spatter Deposits
2
Rough, Uneven Bead
3
Slight Crater During Welding
4
Bad Overlap
5
Poor Penetration
1
2
3
4
5
102
S-0053-A
2-8. Good Weld Bead Characteristics
1
2
Fine Spatter Or No Spatter
2
Uniform Bead
3
Moderate Crater During
Welding
4
No Overlap
5
Good Penetration Into Base
Metal
5
4
3
1
S-0052-B
2-9. Common GMAW Shielding Gases
This is a general chart for common gases and where they are used. Many different combinations (mixtures) of shielding gases have been developed over the years.
Gas
Spray Arc
Steel
Short
Circuiting
Steel
Spray Arc
Short
Stainless Steel Circuiting
Stainless
Steel
Argon
Argon + 1% O2
Flat & Horizontal5
Fillet
Flat & Horizontal5
Fillet
Argon + 2% O2
Flat & Horizontal5
Fillet
Flat & Horizontal5
Fillet
Argon + 5% O2
Flat & Horizontal5
Fillet
Argon + 8%
CO2
Flat & Horizontal5
Fillet
All Positions
Argon + 25%
CO2
Flat & Horizontal1
Fillet
All Positions
Argon + 50%
CO2
CO2
Spray Arc
Aluminum
Short
Circuiting
Aluminum
All Positions5
All Positions
All Positions
Flat & Horizontal1
Fillet
All Positions
Helium
All Positions2
Argon +
Helium
All Positions2
Tri-Mix4
1
2
3
Globular Transfer
Heavy Thicknesses
Single Pass Welding Only
All Positions
4
5
90% HE + 7-1/2% AR + 2-1/2% CO2
Also for GMAW-P, All Positions
103
SECTION 3 − MODES OF GMAW TRANSFER
. GMAW transfer mode is determined by variables such as shielding gas type, arc voltage, arc current, diameter of electrode and wire feed speed.
3-1. Short Circuit Transfer
1
Short Circuit Transfer
Short circuit transfer refers to the
welding wire actually “short circuiting” (touching) the base metal between 90 - 200 times per second.
With short circuit transfer, wire feed
speeds, voltages, and deposition
rates are usually lower than with other types of metal transfer such as
spray transfer. This makes short circuit transfer very versatile allowing
the welder to weld on thin or thick
metals in any position.
1
Limitations of short circuit transfer:
S A relatively low deposition rate
S Lack of fusion on thicker metals
S More spatter
. Short circuit transfer usually has
a crackling (bacon frying) sound
when a good condition exists.
2
Short Circuit Cycle
A - Electrode is short circuited to
base metal. No arc, and current
is flowing through electrode
wire and base metal.
B - Resistance increases in electrode wire causing it to heat,
melt and “neck down”.
2
C - Electrode wire separates from
weld puddle, creating an arc.
Small portion of electrode wire
is deposited which forms a
weld puddle.
D - Arc length and load voltage are
at maximum. Heat of arc is flattening the puddle and increasing the diameter tip of electrode.
E - Wire feed speed overcomes
heat of arc and wire
approaches base metal again.
F - Arc is off and the short circuit
cycle starts again.
Ref. 804 879-A
104
3-2. Globular Transfer
1
Globular Transfer
Globular transfer refers to the state of
transfer between short-circuiting and
spray arc transfer. Large globs of
wire are expelled off the end of the
electrode wire and enter the weld
puddle.
1
Globular transfer can result when
welding parameters such as voltage,
amperage and wire feed speed are
somewhat higher than the settings
for short circuit transfer.
Limitations of globular transfer:
S Presence of spatter
S Less desirable weld appearance
than spray arc transfer
S Welding is limited to flat positions
and horizontally fillet welds
S Welding is limited to metal 1/8 inch
(3 mm)or thicker
Ref. 804 879-A
3-3. Spray Arc Transfer
1
Spray Arc Transfer
Spray arc transfer “sprays” a stream
of tiny molten droplets across the
arc, from the electrode wire to the
base metal.
Spray arc transfer uses relatively
high voltage, wire feed speed and
amperage values, compared to short
circuit transfer.
1
. To achieve a true spray transfer,
an argon-rich shielding gas must
be used.
When proper parameters are used,
the spray arc transfer produces a
characteristic humming or buzzing
sound.
Advantages of spray arc transfer:
S High deposition
S Good fusion and penetration
S Good bead appearance
S Capability of using larger diameter
wires
S Presence of very little spatter
Limitations of spray arc transfer:
S Used only on material 1/8 inch
(3 mm) and thicker (hand held)
S Limited to flat and horizontal fillet
weld position (except for some spray
transfer on aluminum)
S Good fit-up is always required as
there is no open root capability
Ref. 804 879-A
105
SECTION 4 − GMAW WELDING TROUBLESHOOTING
4-1. Excessive Spatter
Excessive Spatter − scattering of
molten metal particles that cool to
solid form near weld bead.
Possible Causes
Corrective Actions
Wire feed speed too high.
Select lower wire feed speed.
Voltage too high.
Select lower voltage range.
Electrode extension (stickout) too long.
Use shorter electrode extension (stickout).
Workpiece dirty.
Remove all grease, oil, moisture, rust, paint, undercoating, and dirt from work surface before welding.
Insufficient shielding gas at welding
Increase flow of shielding gas at regulator/flowmeter and/or prevent drafts near welding arc.
arc.
Dirty welding wire.
Use clean, dry welding wire.
Eliminate pickup of oil or lubricant on welding wire from feeder or liner.
4-2. Porosity
Porosity − small cavities or holes
resulting from gas pockets in weld
metal.
Possible Causes
Corrective Actions
Inadequate shielding gas coverage.
Check for proper gas flow rate.
Remove spatter from gun nozzle.
Check gas hoses for leaks.
Eliminate drafts near welding arc.
Place nozzle 1/4 to 1/2 in. (6-13 mm) from workpiece.
Hold gun near bead at end of weld until molten metal solidifies.
Wrong gas.
Use welding grade shielding gas; change to different gas.
Dirty welding wire.
Use clean, dry welding wire.
Eliminate pick up of oil or lubricant on welding wire from feeder or liner.
Workpiece dirty.
Remove all grease, oil, moisture, rust, paint, coatings, and dirt from work surface before welding.
Use a more highly deoxidizing welding wire (contact supplier).
Welding wire extends too far out of
Be sure welding wire extends not more than 1/2 in. (13 mm) beyond nozzle.
nozzle.
106
4-3. Incomplete Fusion
Incomplete Fusion − failure of weld
metal to fuse completely with base
metal or a preceeding weld bead.
Possible Causes
Corrective Actions
Workpiece dirty.
Remove all grease, oil, moisture, rust, paint, coatings, and dirt from work surface before welding.
Insufficient heat input.
Select higher voltage range and/or adjust wire feed speed.
Improper welding technique.
Place stringer bead in proper location(s) at joint during welding.
Adjust work angle or widen groove to access bottom during welding.
Momentarily hold arc on groove side walls when using weaving technique.
Keep arc on leading edge of weld puddle.
Use correct gun angle of 0 to 15 degrees.
4-4. Excessive Penetration
Excessive Penetration − weld metal
melting through base metal and
hanging underneath weld.
Excessive Penetration
Good Penetration
Possible Causes
Corrective Actions
Excessive heat input.
Select lower voltage range and reduce wire feed speed.
Increase travel speed.
4-5. Lack Of Penetration
Lack Of Penetration − shallow
fusion between weld metal and
base metal.
Lack of Penetration
Good Penetration
Possible Causes
Corrective Actions
Improper joint preparation.
Material too thick. Joint preparation and design must provide access to bottom of groove while maintaining proper welding wire extension and arc characteristics.
Improper weld technique.
Maintain normal gun angle of 0 to 15 degrees to achieve maximum penetration.
Keep arc on leading edge of weld puddle.
Be sure welding wire extends not more than 1/2 in. (13 mm) beyond nozzle.
Insufficient heat input.
Select higher wire feed speed and/or select higher voltage range.
Reduce travel speed.
107
4-6. Burn Through
Burn-Through − weld metal melting
completely through base metal
resulting in holes where no metal remains.
Possible Causes
Corrective Actions
Excessive heat input.
Select lower voltage range and reduce wire feed speed.
Increase and/or maintain steady travel speed.
4-7. Waviness Of Bead
Waviness Of Bead − weld metal that
is not parallel and does not cover
joint formed by base metal.
Possible Causes
Corrective Actions
Unsteady hand.
Support hand on solid surface or use two hands.
4-8. Distortion
Distortion − contraction of weld metal during welding that forces base
metal to move.
Base metal moves
in the direction of
the weld bead.
Possible Causes
Corrective Actions
Excessive heat input.
Use restraint (clamp) to hold base metal in position.
Make tack welds along joint before starting welding operation.
Select lower voltage range and/or reduce wire feed speed.
Increase travel speed.
Weld in small segments and allow cooling between welds.
108
REMEMBER
HARD WORK OR
LIGHT WORK
SAFETY MUST BE
THE NETWORK
109
WELDING PROCESS GUIDE
110
SHIELDING GASES
1. Problems faced, due to improper shielding gas or gas mixtures; used during
the process of MIG Welding.





High Spatter
Poor weld appearance
Excessive Fumes
Low Productivity
Rework due to quality rejection
2. Characteristics of various gases used for MIG welding



Argon : Produces a quite, smooth arc with excellent metal transfer and
minimal spatter.
Carbon Di Oxide : Promotes a bowl-like penetration shape for a strong,
tough weld. Penetration increases with Carbon di Oxide content.
Oxygen : Focuses the arc and gives a final spray. Also increases weld
proof fluidity to give faster welding and improved welding with the parent
plate, so that the weld blends smoothly into it.
3. Cost components involved in the process of MIG welding.




The labour component
The wire or consumable usage
The shielding gas
Power consumption
approx. 60%
approx. 32%
approx. 1.5%
approx. 6.5%
4. Conclusion :
From above table it reveals that reducing the cost of the weld or improving the
weld productivity is greatly enhanced by the use of the right shielding gas for
the job. The right shielding gas will help to reduce the labour component by –





Increasing welding speed.
Reducing clean-up time (less spatter).
Improving the quality of weld (reduced weld rejection).
Reducing inefficient deposition of wire (excessive spatter and convex
bead shape).
Greater operator satisfaction (is of welding).
111
SELECTION FOR SHIELDING GAS FOR MIG/TIG WELDING
Gas or Gas Mixture
Oxygen
Nitrogen
Helium
Argon
Hydrogen
Carbon Di Oxide
Propane
Acetylene
Air(blended)
Ar 93% + CO2 5% + O2 2%
Ar 78% + CO2 20% + O2 2%
Ar 85% + CO2 13.5% + O2
1.5%
Ar 92% + CO2 8%
Ar 80% + CO2 15% + O2 5%
Application
Welding and cutting
Freezing, purging, certain steels, plasma cutting.
TIG welding of non-ferrous metals and alloys.
General TIG application.
Non- toxic, smooth arcs, easy start, little spatter.
Used in MIG and TIG welding and in gas mixtures.
MAG welding of Stainless Steel. Very inflammable
Sometimes used on its own for welding. Also
mixed with other gases.
For cutting and heating when used with oxygen
Welding and cutting.
Cutting
Thin low carbon steel. Low spatter, pulse arc.
Thick low carbon steel. Reduced spatter. Not
suitable for pulse.
Most sections. Low carbon steel. Smooth arc.
Minimum spatter. Suitable pulse arcs and has
robotic uses.
CO2 component controls penetration and bead
shape for welding strength. Improves wetting and
viscosity.
Oxygen content stabilizes the arc, improves
wetting and gives good fusion.
Used for the MIG and MMA welding for stainless
steel. Reasonable spatter.
For TIG welding of stainless steels.
Ar 97-98% + O2 1-3%
Ar 95-99% + H2 1-5%
112
TROUBLE SHOOTING GUIDE
Trouble Shooting
Where to begin?
Listen to the customer
Restate the problem to the customer to determine if you have correctly heard what
they are saying.
If problem can be solved with literature (Ordering Problem) or other simple means.
FIX IT!
If solution to problem will require the help of others from inside or outside our
organization – GET THE FACTS.
Weld Parameter
Amps/Volts, Wire Type and Size
Gas mix being used, Flow rate.
Process being used.
DOES IT MAKE SENSE SO FAR?
Study the problem
Has the problem been present for a long time, or is the problem “New”?
If the problem is new, what has changed?
If you are on site can you witness the problem?
Where to end
If you have fixed the problem inform office of “Fix”
Follow up to see if problem has “Stayed Fixed”
If you have not fixed the problem inform office that the problem is out of your hands
Offer solutions
What would YOU do to solve the problem?
113
Porosity:
Porosity is caused by four main possibilities:
Base metal Contamination
Filler metal Contamination
Atmosphere in the element including gas turbulence.
Welding Parameters.
Binzel has found that most porosity problems are directly related to a gas problem,
followed by problems with base metal contamination.
Problem
Base metal
Probable Causes
Impurities on base metal
Filler Metal
Impurities on filler metal
(wire)
Solution
Remove Contamination.
Use of specific wire / gas mix for specific
types of impurities.
Replace wire.
Install wire-cleaning system.
Prevent industrial dust/dirt/grit from
contaminating the wire during storage or
use.
Remove wire from wire drive unit and store
in sealed plastic bag when not in use for
long periods.
Use aluminum wire quickly to prevent build
up of aluminum oxide on surface.
Protect weld area from drafts.
Gas
Atmosphere
in weld
Drafts, wind, fans, etc.
Use tapered or bottle neck gas nozzles
when drafts cannot be avoided.
Reduce gas flow.
Fix all hose connection points.
Too high gas flow causing
turbulence and /or sucking
air at connectional points:
creating venturi effect at
the end of gas nozzle.
Too low gas flow causing
insufficient gas coverage.
Damaged or kinked gas
lines.
Too high oxygen content.
Increase gas flow.
Repair.
Fix mixer.
Gas Mixing
Apparatus.
Fix leaks.
Leaks in gas distribution
system.
114
Gas
turbulence.
Porosity
Overhaul system fit filters and / or dryers.
Other impurities in gas
moisture, etc.
Non-consistent delivery of
flow (cfh) at torch
connection.
Excessive spatter build up
in gas nozzle / contact tip.
Nozzle damage causing
uneven gas coverage
Torch gas ports clogged
or deformed.
Super heated nozzle
causing shielding gas to
expand rapidly creating
return effect at end of
nozzle leading to
contamination of gas by
atmosphere.
Missing gas diffuser
nozzle insulator.
Too high gas flow causing
venturi effect.
Too long wires stick out
gas nozzle too far from
weld puddle.
Bad torch position – too
sharp torch incline
causing venturi effect at
the end of nozzle leading
to atmospheric
contamination.
Excessive wide weld pool
for nozzle I.D
Arc voltage too high.
Too high travel speed.
Slipping feed rolls.
Regulated pressure into flow meter for
consistent delivery of cfh.
Clean nozzle and tip.
Change nozzle.
Clean or replace.
Check duty cycle rating of torch.
Check for correct water pressure and flow if
water-cooled torch is used.
Use suitable rated cooler: change to watercooled gas nozzle.
Replace.
Reduce gas flow.
Use longer nozzle.
Correct torch angle.
Use wider gas nozzle.
Reduce voltage.
Reduce speed.
Check that the feed roll size is correct for
the wire size being used. Increase the drive
roll pressure until the wire feed is even. Do
not apply excessive pressure as this can
damage the wire surface and may cause
copper coating to loosen from steel wires
or metal shavings to be formed from soft
wires like aluminum which will be drawn
into the wire feed conduit and will rapidly
clog the liner. When welding with flux-cored
Erratic wire
feed
115
wires, excessive drive roll pressure may
open the wire seam and allow flux or metal
powers to escape.
Erratic wire
feed
Clogged or worn liner.
Dust, particles of copper, drawing
lubricants, metal or flux and other forms of
contamination rapidly clog the liner so that
the feed is impeded. A liner which has
been in use for an extended period of time
becomes worn and saturated with dust and
must be replaced.
When changing wire, remove the contact
tip from the front end of the gun and blow
out the liner with clean, dry compressed air
from the back of the gun. Note: Wear
safety goggles when using compressed air
to clean liner. Insure proper safety
procedures are followed to avoid possible
serious eye injury.
Check the length of the liner and either trim
if too long or replace the liner if too short.
Proper feed of the welding wire is
dependent upon the correct length of the
liner. Consult the operating instructions for
the gun or contact your local Authorized
Binzel Distributor for further information.
An unprotected coil of wire quickly collects
dust and other airborne contamination. If
grinding is being performed in the vicinity,
particles can become attached to the wire,
severely interfering with the wire feed.
Replace with clean wire and keep it
protected with a cover.
Set the break so that the coil immediately
stops rotating as soon as welding is
interrupted. If the brake is applied too hard
it will cause the feed rolls to slip, resulting
in uneven wire feed. If it is too loose,
overrun of the wire will occur, causing
tangles of the wire irregular tension in the
feed mechanism and irregular arc
characteristics.
Liner too long or too short.
Spatter on wire.
Coil break incorrectly
adjusted.
116
ProblemProbable Causes
Unstable ArcIncorrect setting of voltage
and / or current
Solution
Set the wire feed in relation to the arc
voltage in such a way that the arc burns
evenly and stable. In spray arc welding,
set the wire feed so that short-circuiting
ceases and so that the filler metal is
transferred in a spray across the arc.
Defects in wire feed.
Porosity
Find the cause of the interference and
correct the condition. (See action “Erratic
wire feed”.)
Worn contact tips.When the opening of the contact tip has
become too badly worn the wire will no
longer will be in continuous electrical
contact, which will result in an unstable
arc and an increase in spatter.
Impurities on the basePaint, mill scale, rust, silicon scale or flux
metal.deposits from the previous weld runs
from an insulating layer causing an
unstable arc. Clean the surface to be
welded.
Poor contact betweenSecurely attach the ground cable as
ground cable and workclose to the point of welding as possible
piece.on the work piece. Clean the surfaces to
ensure good contact.
Loose power connection.Check to ensure welding power
connection on the power is tight, the
connection on the wire feeder is tight, the
connection on the adaptor block is tight,
and the connection of the gun to the
adaptor block is tight.
Stick out too long.Adjust the contact tip to work distance to
a minimum of 3/8” for short arc welding
with small diameter wires.
Drafts, wind, fans, exhaust Protect the work piece from drafts with
ducts, etc.curtains or screens. Drafts can easily
draw away the shielding gas from the
weld pool leaving it without sufficient gas
protection.
Impurities on the baseRemove all contamination from the
metal.surfaces to be welded. Paint, mill scale,
rust, grease and other contamination can
cause porosity in the weld.
Unsuitable joint fit-up.Minimize gaps or provide backing.
117
Porosity
Spatter in nozzle and on
contact tip.
Clean the nozzle and the contact tip
regularly. Spatter on these parts causes
turbulence on the gas flow, causing air to
be become mixed into the shielding gas
resulting in porosity. Do not hit the nozzle
to remove spatter, use a suitable scraper.
Consult your welding engineer for proper
flow rate. Check accuracy of regulator
using Binzel Gas checker (P/N
191.0013), which is available from your
authorized Alexander Binzel Distributor.
Too low a gas flow rate gives insufficient
protection to the weld pool. Too high a
gas flow rate causes turbulence in the
gas shield, which in turn can suck in air
resulting in porosity.
Replace nozzle. A nozzle with uneven
edges gives rise to turbulence in the gas
flow. Do not hit nozzle to remove spatter,
use a suitable scraper
Generally, set the stick-out at about 15
times the diameter of the wire being used.
If a longer or shorter stick-out than normal
is required, consult your Authorized
Alexander Binzel Distributor about the
availability of special nozzles. Many types
are available.
Direct the gun at the weld puddle when
critical areas like external corners, edges
and joints with wide gaps are
encountered. A too sharply inclined
welding gun can cause porosity due to
misdirection of the shielding gas from the
nozzle or air entrapment.
The width of the weld pool should not
exceed 1.3 times the diameter of the
nozzle. A wider weld pool will be insufficiently protected by the shielding gas
when the air gets mixed into the outer
layer of the gas stream. If necessary, a
shielding gas post-flow should be applied.
Consult your Authorized Alexander Binzel
Distributor about the availability of special
nozzles that may help you weld wide
joints.
Too high or too low gas
flow rate.
Nozzle damaged.
Too long a stick-out.
Misdirected welding gun.
Excessively wide weld
pool in spray arc welding
or too high welding speed.
118
Problem
Porosity
Probable Causes
Damaged, kinked or
leaking gas hose.
Solution
Inspect and repair or replace as
necessary. Consult your Authorized
Alexander Binzel Distributor for genuine
Alexander replacement parts.
Inspect and replace as necessary.
Consult your Authorized Alexander Binzel
Distributor for genuine Alexander
replacement parts.
Set the wire feed rate and voltage in
accordance with good welding practices
as recommended by a qualified welding
engineer.
Adjust the wire feed and voltage so that
the arc is in accordance with good
welding practice for the joint to be
welded. The distance from the welding
gun to the work-piece should be about ½”
to 1”. If the arc is too long there will be
spatter, usually in the direction of the
weld.
If the contact tip becomes worn the filler
will not be in constant contact with the arc
will become unstable. A contact tip
contaminated with spatter will cause
uneven wire feed resulting in further
spatter.
The angle of the gas nozzle relative to the
work-piece should be between 45 to 90
degrees. If the angle is too small, the wire
runs parallel to the weld pool, resulting
spatter in the direction of welding.
Have the power source checked for faulty
conditions such as broken wires or faulty
contact.
Damaged or missing
nozzle insulator or gas
diffuser.
Spatter
Too fast or too slow wire
feed in relation to the arc
voltage.
Too long arc.
Damaged contact tip.
Inclination of the welding
gun too great.
Faulty power source.
119
Problem
Spatter
Probable Causes
Incorrect start.
Incorrect pulse
parameters.
Uneven wire feed.
Impurities on the base
metal.
Poor ground contact.
Too long stick out (short
arc welding)
Solution
A lot spatter occurs if the stick out is too
great and if the welding gun is held too far
from the work piece when striking the arc.
Try to start with as short stick out as
possible and with the welding gun as
close to the starting point as possible. If a
large ball end is formed on the end of the
welding wire remove it by cutting the wire
with sharp wire cutters. It is helpful if the
wire is cut to a point. Always remove the
ball end before striking aluminum arc.
Check welding ground connection.
Consult the user manual for your power
supply or a qualified welding engineer.
Uneven wire feed gives rise to heavy
spatter. Find the cause of the disturbance
and correct the condition before
proceeding.
Paint, mill scale and other contamination
on the base metal form an insulating layer
causing an unstable arc, which results in
heavy spatter. Clean the surfaces to be
welded.
Inspect ground cable for loose
connection, fraying and cuts. Correct the
problem areas found and attach the
ground cable directly to the work piece
after having cleaned the contact surface
first. POOR GROUNG CONTACT IS THE
MOST COMMON CAUSE OF
UNSTABLE MIDGE WELDING
CONDITIONS.
The stick out should be 15 times the
diameter of the electrode being used.
With increasing stick out the current is
reduced and the arc voltage rises, giving
a longer unstable arc and increased
spatter.
Check for correct polarity. Follow the
electrode manufactures
recommendations.
Incorrect polarity.
120
TROUBLE SHOOTING GUIDE – GAS / AIR COOLED GUNS
Problem
Gun too hot
Probable Cause
Poor ground.
Solution
Inspect ground cable for loose connection,
fraying and cuts. Correct any problem
areas found. Clean cramping area to insure
good contact. Securely attach ground cable
to work piece as close as possible to the
point of welding. Insure good connection to
welding power source.
Loose power connection.Check to ensure power connection on
power source is tight, the connection on the
wire feeder is tight, the connection on the
adaptor block is tight, and the connection of
the gun to the adaptor block is tight.
Loose Bikox connection.Remove handle assembly and adaptor
support. Check to ensure Bikox connection
to the swan neck is tight and the Bikox
connection to the adaptor block is tight.
Damaged Bikox assembly. Visually inspect the Bikox assembly for cuts
and tear’s. Replace Bikox assembly if
necessary.
Consumable items looseRemove nozzle from gun and inspect
or worn.contact tip and contact tip holder/ gas
diffuser for wear and tightness, replace or
tighten if necessary.
Capacity of gun beingNote complete weld parameter including
exceeded.welding current in (AMPS), welding voltage,
wire feed speed, type and size of wire, type
of gas and flow rate of gas and consult your
local Authorized Alexander Binzel
Distributor.
Erratic wire feedSee Erratic wire feed section in “Trouble
Shooting Guide General” Published by
Alexander Binzel Corporation.
121
TROUBLE SHOOTING GUIDE – WATER COOLED GUNS
Problem
Gun too hot
Probable Cause
Poor water flow.
Solution
Insure water flow is unrestricted and
provides a minimum of 1.5 qts. Per min
flow at pressure does not exceed 65psi.
Insure that water flow direction is into the
gun through the blue water line and out of
the gun through the red water line.
Insure that a water cooler run for a
minimum of 5 min after welding is
completed. This ensures proper post-weld
cooling can take place through the entire
gun and cable assembly.
Clean coolant after first disconnecting it
from the line voltage and draining old
coolant fluid. Consult the manufacturer of
the unit for proper procedure. Refill unit
with fresh clean coolant fluid.
See “Poor ground” in section marked “Gas /
Air cooled Guns.”
Check to ensure power connection on the
power source is tight, the connection on the
wire feeder is tight, the connection on the
adaptor block is tight, and the connection of
the gun to he adaptor block is tight.
See “Capacity of gun is being exceeded” in
section “Gas / Air cooled Guns”.
The use of water cooled MIG gun without
water, even for very short periods of time,
will destroy the power cable located inside
the cable assembly. Longer periods of use
without water will destroy the swan neck of
the gun in addition to multiple components
within the assembly. Consult your local
Authorized Alexander Binzel Distributor for
information regarding “Fast Gun” ™ repair
program, or contact the Binzel Repair
Department direct at 1-800-542-4867 for
information regarding our exclusive 2 day
program.
Direction of flow reversed.
Interrupted water flow.
Dirty Coolant.
Poor ground.
Loose power connection.
Capacity of gun is being
exceeded.
Water-cooling source not
turned on during welding.
Water leaks.
-X-
122
REMEMBER
Smart
worker is a
safe worker
123
OXYFUEL SAFETY
124
SECTION 1 − SAFETY PRECAUTIONS - READ BEFORE USING
OXY FUEL 2013−09
Protect yourself and others from injury — read, follow, and save these important safety precautions and operating instructions.
1-1. Symbol Usage
. Indicates special instructions.
DANGER! − Indicates a hazardous situation which, if
not avoided, will result in death or serious injury. The
possible hazards are shown in the adjoining symbols
or explained in the text.
Indicates a hazardous situation which, if not avoided,
could result in death or serious injury. The possible
hazards are shown in the adjoining symbols or explained in the text.
This group of symbols means Warning! Watch Out! ELECTRIC
SHOCK, MOVING PARTS, and HOT PARTS hazards. Consult symbols and related instructions below for necessary actions to avoid the
hazards.
NOTICE − Indicates statements not related to personal injury.
1-2. Welding, Cutting, Brazing, And Heating Hazards
FUMES AND GASES can be hazardous.
The symbols shown below are used throughout this manual
to call attention to and identify possible hazards. When you
see the symbol, watch out, and follow the related instructions
to avoid the hazard. The safety information given below is
only a summary of the more complete safety information
found in the Safety Standards listed in Section 1-4. Read and
follow all Safety Standards.
Welding and cutting produces fumes and gases.
Breathing these fumes and gases can be hazardous
to your health.
D Keep your head out of the fumes. Do not breathe the fumes.
D If inside, ventilate the area and/or use local forced ventilation at the
flame to remove welding and cutting fumes and gases. Some
gases (natural gas and acetylene) are lighter than air and will collect in high areas. Other gases (propane and butane) are heavier
than air and will collect in low areas. Heavier-than-air gases are
more difficult to diffuse and are more likely to accumulate. The recommended way to determine adequate ventilation is to sample for
the composition and quantity of fumes and gases to which personnel are exposed.
D If ventilation is poor, wear an approved air-supplied respirator.
D Read and understand the Safety Data Sheets (SDSs) and the
manufacturer’s instructions for adhesives, coatings, cleaners,
consumables, coolants, degreasers, fluxes, and metals.
D Work in a confined space only if it is well ventilated, or while
wearing an air-supplied respirator. Always have a trained watchperson nearby. Welding and cutting fumes and gases can displace
air and lower the oxygen level, causing injury or death. Be sure the
breathing air is safe. Test atmospheres in confined spaces for explosive and toxic gases before using oxy-fuel equipment.
D Do not weld or cut in locations near degreasing, cleaning, or spraying operations. The heat from welding or cutting flame can react
with vapors to form highly toxic and irritating gases.
D Do not weld or cut on coated metals, such as galvanized, lead, or
cadmium-plated steel unless the coating is removed from the affected area, the area is well ventilated, and while wearing an airsupplied respirator. The coatings and any metals containing these
elements can give off toxic fumes if welded or cut.
D Do not weld or cut on sealed air conditioning or refrigeration systems unless all refrigerants have been removed from the system.
Only qualified persons should install, operate, maintain, and
repair this equipment.
During operation, keep everybody, especially children, away.
Do not use this equipment unless you are trained in its proper
use or are under competent supervision. Follow the procedures described in this booklet every time you use the equipment. Failure to follow these instructions may cause fire, explosion, asphyxiation, property damage, or personal injury.
This equipment must be used in accordance with all Federal,
State, and local regulations as well as DOT (Department of
Transportation) and CGA (Compressed Gas Association)
regulations. Contact your gas supplier for more information
on the proper use of compressed gases.
. In this document, the phrase “welding and cutting” also refers to other oxy-fuel operations like brazing and heating.
READ INSTRUCTIONS.
D Read and follow all labels and the Owner’s
Manual carefully before installing, operating, or
servicing equipment. Read the safety information at the beginning of the manual and in each
section.
D Use only genuine replacement parts from the manufacturer.
D Perform maintenance and service according to the Owner’s
Manuals, industry standards, and national, state, and local
codes.
LIGHT RAYS can burn eyes and skin.
Light rays from the welding and cutting process
produce intense visible and invisible (ultraviolet and
infrared) rays that can burn eyes and skin. Sparks fly
off from the weld.
D Wear approved face protection fitted with a proper shade of filter
lenses to protect your face and eyes from light rays and sparks
when welding, cutting, or watching (see ANSI Z49.1 and Z87.1
listed in Safety Standards).
D Wear welding goggles, or wear welding helmet /welding faceshield
over approved goggles/safety glasses with side shields.
D Use protective screens or barriers to protect others from flash,
glare and sparks; warn others not to watch the welding or cutting.
D Wear body protection made from durable, flame-resistant material
(leather, heavy cotton, wool). Body protection includes oil-free
clothing such as leather gloves, heavy shirt, cuffless trousers, high
shoes, and a cap.
HOT PARTS can burn.
D Do not touch hot parts bare handed.
D Allow cooling period before working on equipment.
D To handle hot parts, use proper tools and/or
wear heavy, insulated welding gloves and clothing to prevent burns.
125
D Do not weld or cut where flying sparks can strike flammable
material.
D Protect yourself and others from flying sparks and hot metal.
D Be alert that welding and cutting sparks and hot materials from
welding and cutting can easily go through small cracks and openings to adjacent areas.
D Watch for fire, and keep a fire extinguisher nearby.
D Be aware that welding or cutting on a ceiling, floor, bulkhead, or
partition can cause fire on the hidden side.
D Do not weld or cut on containers that have held combustibles, or on
closed containers such as tanks, drums, or pipes unless they are
properly prepared according to AWS F4.1 and AWS A6.0 (see
Safety Standards).
D Do not weld or cut where the atmosphere may contain flammable
dust, gas, or liquid vapors (such as gasoline).
WELDING AND CUTTING can cause
fire or explosion.
Welding and cutting on closed containers, such as
tanks, drums, or pipes, can cause them to blow up.
Sparks can fly off from the welding or cutting
operations. The flying sparks, hot workpiece, and hot
equipment can cause fires and burns. Check and be sure the area is
safe before doing any welding or cutting.
D Do not use this welding and cutting equipment with gases and
pressures other than those for which it is intended. Oxygen is not
flammable; however, the presence of pure oxygen will drastically
increase the speed and force with which burning takes place. Oxygen must never be allowed to contact grease, oil, or other petroleum-based substances; therefore, be sure there is no oil or
grease on the regulator, cylinder, valves, or equipment. Do not use
petroleum-based pipe sealants. Do not use or store near excessive heat (above 125° F/51.5° C) or open flame. Do not refer to oxygen as air and do not use oxygen as a substitute for compressed
air. Do not use oxygen to clean clothes or work area, for ventilation,
or to operate pneumatic tools. Open oxygen cylinder valves slowly. Be sure regulator adjusting handle is in the full out (off) position
before opening oxygen cylinder valve.
D Inspect all equipment before use. Do not use damaged, defective,
or improperly adjusted welding and cutting equipment. Make sure
levers and valves work properly, threads on equipment are clean
(no grease or oil) and not deformed, gauges are intact and easy to
read, regulator is clean and free of oil or dirt, and fittings are properly sized for the cylinder. Make sure hoses are clean (no grease or
oil) and ferrules are properly installed so the fitting does not slip inside the hose. Be sure all connections are tight.
D It is recommended that a reverse-flow check valve or a flashback
arrestor be installed between the torch handle and the regulator.
Check valves do not prevent the propagation of a flame upstream
(flashback) but are designed to prevent the unintentional backflow
of gases into the cutting attachment, torch, hoses, or regulator
which could cause an explosion or fire. A flashback arrestor can
be installed on the torch handle instead of a check valve. Miller
flashback arrestor have a reverse flow check valve and prevent
the propagation of a flame upstream. If a flashback arrestor is installed, a check valve is not necessary. Using a flashback arrestor
and a check valve may reduce gas flow and affect torch operation.
To help prevent the reverse flow of gases, be sure the cylinders
contain enough gas to complete the work.
D Perform work only in an area with a fireproof floor (concrete). Do
not heat concrete because it may expand and explode violently.
D Perform work on a fireproof surface. Use heat resistant shields to
protect nearby walls and flooring.
D Do not use if grease or oil is present on equipment or if equipment is
damaged. Have equipment cleaned/repaired by a qualified person.
D Do not open a cylinder valve quickly or the regulator may be damaged and cause a fire.
D Do not open acetylene cylinder valve more than 3/4 turn. (For all
gases except acetylene, open cylinder valve fully to backseal the
cylinder valve.) Keep cylinder wrench on the cylinder for quick
shut-off.
D Do not slightly open or “crack” fuel cylinder valve to blow debris
from the valve outlet. Remove the debris using nitrogen, air, or a
clean, oil-free rag.
D Always purge gas from the system before lighting torch. Purge gas
in a well-ventilated area and away from flame or sparks.
D Keep torch flame or sparks away from cylinder, regulator, and gas
hose.
D Use only the gases recommended by the manufacturer of the
oxy-fuel equipment being used.
D Never light a torch with matches or a lighter. Always use a striker.
D Do not use acetylene above 15 psi (103 kPa) flowing. It is acceptable to use acetylene regulators that indicate a static pressure up
to 22 psi (151 kPa).
D Check oxy-fuel system for leaks with an approved leak detection
solution or leak detector. Never test for gas leaks with a flame.
D Wear body protection made from durable, flame-resistant material
(leather, heavy cotton, wool). Body protection includes oil-free
clothing such as leather gloves, heavy shirt, cuffless trousers, high
shoes, and a cap.
D Do not use fuel gases to clean clothes or work area.
D Remove any combustibles, such as a butane lighter or matches,
from your person before doing any welding or cutting.
D After completion of work, inspect area to ensure it is free of sparks,
glowing embers, and flames.
D Follow requirements in OSHA 1910.252 (a) (2) (iv) and NFPA 51B
for hot work and have a fire watcher and extinguisher nearby.
BUILDUP OF GAS can injure or kill.
D Shut off compressed gas supply when not in
use.
D Always ventilate confined spaces or use
approved air-supplied respirator.
CYLINDERS can explode if damaged.
Compressed gas cylinders contain gas under high
pressure. If damaged, a cylinder can explode. Since
gas cylinders are normally part of the welding or
cutting process, be sure to treat them carefully.
D Protect compressed gas cylinders from excessive heat, mechanical shocks, physical damage, slag, open flames, and sparks.
D Install cylinders in an upright position by securing to a stationary
support or cylinder rack to prevent falling or tipping. Do not lay
acetylene cylinders on their sides or acetone will flow out of the cylinder and damage the equipment.
D Keep cylinders away from any arc welding, cutting, or other electrical circuits.
D Never drape a welding or cutting torch over a gas cylinder.
D Never weld or cut on a pressurized cylinder − explosion will result.
D Use only correct compressed gas cylinders, regulators, hoses,
and fittings designed for the specific application; maintain them
and associated parts in good condition. Do not use compressed
gas cylinder unless an approved gas regulator is attached to the
gas valve.
D Turn face away from valve outlet when opening cylinder valve. Do
not stand in front of or behind the regulator when opening the valve.
D Keep protective cap in place over valve except when cylinder is in
use or connected for use.
D Use the right equipment, correct procedures, and sufficient number of persons to lift and move cylinders.
D Store compressed gas and oxygen cylinders in separate locations.
D Store empty cylinders with valves closed and caps in place.
D Do not modify or repair cylinders or valves. Store leaking acetylene cylinders outdoors in a safe area. Identify leaking cylinders
and return them to the supplier.
D Dispose of used disposable cylinders according to the manufacturer’s recommendations. Do not throw cylinders in fire.
D Remove all flammables within 35 ft (10.7 m) of the welding or cutting operation. If this is not possible, tightly cover them with approved covers.
D Follow instructions provided by the gas supplier and on compressed gas cylinders, associated equipment, and in Compressed
Gas Association (CGA) publication P-1 listed in Safety Standards.
126
FLYING METAL or DIRT can injure eyes.
D Welding, cutting, chipping, wire brushing, and
grinding cause sparks and flying metal.
D Wear welding goggles, or wear welding helmet
/welding faceshield over approved goggles/
safety glasses with side shields.
127
THINK
A SAFETY RULE
BREAKER, IS AN
ACCIDENT MAKER
128
DIESEL ENGINE SAFETY
129
SECTION 1 − SAFETY PRECAUTIONS − READ BEFORE USING
rom_2013−09
Protect yourself and others from injury — read, follow, and save these important safety precautions and operating instructions.
1-1. Symbol Usage
. Indicates special instructions.
DANGER! − Indicates a hazardous situation which, if
not avoided, will result in death or serious injury. The
possible hazards are shown in the adjoining symbols
or explained in the text.
Indicates a hazardous situation which, if not avoided,
could result in death or serious injury. The possible
hazards are shown in the adjoining symbols or explained in the text.
This group of symbols means Warning! Watch Out! ELECTRIC
SHOCK, MOVING PARTS, and HOT PARTS hazards. Consult symbols and related instructions below for necessary actions to avoid the
hazards.
NOTICE − Indicates statements not related to personal injury.
1-2. Arc Welding Hazards
D Always verify the supply ground — check and be sure that input
power cord ground wire is properly connected to ground terminal in
disconnect box or that cord plug is connected to a properly
grounded receptacle outlet.
D When making input connections, attach proper grounding conductor first − double-check connections.
D Keep cords dry, free of oil and grease, and protected from hot metal
and sparks.
D Frequently inspect input power cord and ground conductor for
damage or bare wiring – replace immediately if damaged – bare
wiring can kill.
D Turn off all equipment when not in use.
D Do not use worn, damaged, undersized, or repaired cables.
D Do not drape cables over your body.
D If earth grounding of the workpiece is required, ground it directly
with a separate cable.
D Do not touch electrode if you are in contact with the work, ground,
or another electrode from a different machine.
D Use only well-maintained equipment. Repair or replace damaged
parts at once. Maintain unit according to manual.
D Do not touch electrode holders connected to two welding machines at the same time since double open-circuit voltage will be
present.
D Wear a safety harness if working above floor level.
D Keep all panels and covers securely in place.
D Clamp work cable with good metal-to-metal contact to workpiece
or worktable as near the weld as practical.
D Insulate work clamp when not connected to workpiece to prevent
contact with any metal object.
D Do not connect more than one electrode or work cable to any
single weld output terminal. Disconnect cable for process not in
use.
D Use GFCI protection when operating auxiliary equipment. Do not
test or reset GFCI receptacles at idle speed/low voltage or the
GFCI will be damaged and not provide protection from electric
shock caused by a ground fault.
The symbols shown below are used throughout this manual
to call attention to and identify possible hazards. When you
see the symbol, watch out, and follow the related instructions
to avoid the hazard. The safety information given below is
only a summary of the more complete safety information
found in the Safety Standards listed in Section 1-7. Read and
follow all Safety Standards.
Only qualified persons should install, operate, maintain, and
repair this unit.
During operation, keep everybody, especially children, away.
ELECTRIC SHOCK can kill.
Touching live electrical parts can cause fatal shocks
or severe burns. The electrode and work circuit is
electrically live whenever the output is on. The input
power circuit and machine internal circuits are also
live when power is on. In semiautomatic or automatic wire welding, the wire, wire reel, drive roll housing,
and all metal parts touching the welding wire are
electrically live. Incorrectly installed or improperly
grounded equipment is a hazard.
D Do not touch live electrical parts.
D Wear dry, hole-free insulating gloves and body protection.
D Insulate yourself from work and ground using dry insulating mats
or covers big enough to prevent any physical contact with the work
or ground.
D Do not use AC output in damp areas, if movement is confined, or if
there is a danger of falling.
D Use AC output ONLY if required for the welding process.
D If AC output is required, use remote output control if present on
unit.
SIGNIFICANT DC VOLTAGE exists in inverter power
sources AFTER stopping engine.
D Additional safety precautions are required when any of the following electrically hazardous conditions are present: in damp
locations or while wearing wet clothing; on metal structures such
as floors, gratings, or scaffolds; when in cramped positions such
as sitting, kneeling, or lying; or when there is a high risk of unavoidable or accidental contact with the workpiece or ground. For these
conditions, use the following equipment in order presented: 1) a
semiautomatic DC constant voltage (wire) welder, 2) a DC manual
(stick) welder, or 3) an AC welder with reduced open-circuit voltage. In most situations, use of a DC, constant voltage wire welder
is recommended. And, do not work alone!
D Stop engine on inverter and discharge input capacitors according
to instructions in Maintenance Section before touching any parts.
HOT PARTS can burn.
D Do not touch hot parts bare handed.
D Allow cooling period before working on equipment.
D To handle hot parts, use proper tools and/or
wear heavy, insulated welding gloves and
clothing to prevent burns.
D Disconnect input power or stop engine before installing or
servicing this equipment. Lockout/tagout input power according to
OSHA 29 CFR 1910.147 (see Safety Standards).
D Properly install, ground, and operate this equipment according to
its Owner’s Manual and national, state, and local codes.
130
OM-
D Be alert that welding sparks and hot materials from welding can
easily go through small cracks and openings to adjacent areas.
D Watch for fire, and keep a fire extinguisher nearby.
D Be aware that welding on a ceiling, floor, bulkhead, or partition can
cause fire on the hidden side.
D Do not weld on containers that have held combustibles, or on
closed containers such as tanks, drums, or pipes unless they are
properly prepared according to AWS F4.1 and AWS A6.0 (see
Safety Standards).
D Do not weld where the atmosphere may contain flammable dust,
gas, or liquid vapors (such as gasoline).
D Connect work cable to the work as close to the welding area as
practical to prevent welding current from traveling long, possibly
unknown paths and causing electric shock, sparks, and fire hazards.
D Do not use welder to thaw frozen pipes.
D Remove stick electrode from holder or cut off welding wire at
contact tip when not in use.
D Wear body protection made from durable, flame-resistant material
(leather, heavy cotton, wool). Body protection includes oil-free
clothing such as leather gloves, heavy shirt, cuffless trousers, high
shoes, and a cap.
D Remove any combustibles, such as a butane lighter or matches,
from your person before doing any welding.
D After completion of work, inspect area to ensure it is free of sparks,
glowing embers, and flames.
D Use only correct fuses or circuit breakers. Do not oversize or bypass them.
D Follow requirements in OSHA 1910.252 (a) (2) (iv) and NFPA 51B
for hot work and have a fire watcher and extinguisher nearby.
D Read and understand the Safety Data Sheets (SDSs) and the
manufacturer’s instructions for adhesives, coatings, cleaners,
consumables, coolants, degreasers, fluxes, and metals.
FLYING METAL or DIRT can injure
eyes.
D Welding, chipping, wire brushing, and grinding
cause sparks and flying metal. As welds cool,
they can throw off slag.
D Wear approved safety glasses with side shields even under your
welding helmet.
FUMES AND
hazardous.
GASES
can
be
Welding produces fumes and gases. Breathing these
fumes and gases can be hazardous to your health.
D Keep your head out of the fumes. Do not breathe the fumes.
D If inside, ventilate the area and/or use local forced ventilation at the
arc to remove welding fumes and gases. The recommended way
to determine adequate ventilation is to sample for the composition
and quantity of fumes and gases to which personnel are exposed.
D If ventilation is poor, wear an approved air-supplied respirator.
D Read and understand the Safety Data Sheets (SDSs) and the
manufacturer’s instructions for adhesives, coatings, cleaners,
consumables, coolants, degreasers, fluxes, and metals.
D Work in a confined space only if it is well ventilated, or while
wearing an air-supplied respirator. Always have a trained watchperson nearby. Welding fumes and gases can displace air and
lower the oxygen level causing injury or death. Be sure the breathing air is safe.
D Do not weld in locations near degreasing, cleaning, or spraying operations. The heat and rays of the arc can react with vapors to form
highly toxic and irritating gases.
D Do not weld on coated metals, such as galvanized, lead, or
cadmium plated steel, unless the coating is removed from the weld
area, the area is well ventilated, and while wearing an air-supplied
respirator. The coatings and any metals containing these elements
can give off toxic fumes if welded.
NOISE can damage hearing.
Noise from some processes or equipment can
damage hearing.
D Wear approved ear protection if noise level is
high.
BUILDUP OF GAS can injure or kill.
D Shut off compressed gas supply when not in use.
D Always ventilate confined spaces or use approved air-supplied respirator.
ELECTRIC AND MAGNETIC FIELDS (EMF)
can affect Implanted Medical Devices.
D Wearers of Pacemakers and other Implanted
Medical Devices should keep away.
D Implanted Medical Device wearers should consult their doctor and the device manufacturer before going near arc
welding, spot welding, gouging, plasma arc cutting, or induction
heating operations.
ARC RAYS can burn eyes and skin.
Arc rays from the welding process produce intense
visible and invisible (ultraviolet and infrared) rays
that can burn eyes and skin. Sparks fly off from the
weld.
D Wear an approved welding helmet fitted with a proper shade of filter
lenses to protect your face and eyes from arc rays and sparks
when welding or watching (see ANSI Z49.1 and Z87.1 listed in
Safety Standards).
D Wear approved safety glasses with side shields under your
helmet.
D Use protective screens or barriers to protect others from flash,
glare, and sparks; warn others not to watch the arc.
D Wear body protection made from durable, flame-resistant material
(leather, heavy cotton, wool). Body protection includes oil-free
clothing such as leather gloves, heavy shirt, cuffless trousers, high
shoes, and a cap.
CYLINDERS can explode if damaged.
Compressed gas cylinders contain gas under high
pressure. If damaged, a cylinder can explode. Since
gas cylinders are normally part of the welding
process, be sure to treat them carefully.
D Protect compressed gas cylinders from excessive heat, mechanical shocks, physical damage, slag, open flames, sparks, and arcs.
D Install cylinders in an upright position by securing to a stationary
support or cylinder rack to prevent falling or tipping.
D Keep cylinders away from any welding or other electrical circuits.
D Never drape a welding torch over a gas cylinder.
D Never allow a welding electrode to touch any cylinder.
D Never weld on a pressurized cylinder — explosion will result.
D Use only correct compressed gas cylinders, regulators, hoses,
and fittings designed for the specific application; maintain them
and associated parts in good condition.
D Turn face away from valve outlet when opening cylinder valve. Do
not stand in front of or behind the regulator when opening the valve.
D Keep protective cap in place over valve except when cylinder is in
use or connected for use.
D Use the right equipment, correct procedures, and sufficient number of persons to lift and move cylinders.
D Read and follow instructions on compressed gas cylinders,
associated equipment, and Compressed Gas Association (CGA)
publication P-1 listed in Safety Standards.
WELDING can cause fire or explosion.
Welding on closed containers, such as tanks,
drums, or pipes, can cause them to blow up. Sparks
can fly off from the welding arc. The flying sparks, hot
workpiece, and hot equipment can cause fires and
burns. Accidental contact of electrode to metal objects can cause
sparks, explosion, overheating, or fire. Check and be sure the area is
safe before doing any welding.
D Remove all flammables within 35 ft (10.7 m) of the welding arc. If
this is not possible, tightly cover them with approved covers.
D Do not weld where flying sparks can strike flammable material.
D Protect yourself and others from flying sparks and hot metal.
131
1-3. Engine Hazards
EXHAUST SPARKS can cause fire.
BATTERY EXPLOSION can injure.
D
D
D
D
D
D
D Do not let engine exhaust sparks cause fire.
D Use approved engine exhaust spark arrestor in
required areas — see applicable codes.
D Always wear a face shield, rubber gloves, and
protective clothing when working on a battery.
D Stop engine before disconnecting or connecting battery cables, battery charging cables (if
applicable), or servicing battery.
Do not allow tools to cause sparks when working on a battery.
Do not use welder to charge batteries or jump start vehicles unless the unit has a battery charging feature designed for this purpose.
Observe correct polarity (+ and −) on batteries.
Disconnect negative (−) cable first and connect it last.
Keep sparks, flames, cigarettes, and other ignition sources
away from batteries. Batteries produce explosive gases during
normal operation and when being charged.
Follow battery manufacturer’s instructions when working on or
near a battery.
HOT PARTS can burn.
D Do not touch hot parts bare handed.
D Allow cooling period before working on equipment.
D To handle hot parts, use proper tools and/or
wear heavy, insulated welding gloves and
clothing to prevent burns.
STEAM AND HOT COOLANT can burn.
D If possible, check coolant level when engine is
cold to avoid scalding.
D Always check coolant level at overflow tank, if
present on unit, instead of radiator (unless told
otherwise in maintenance section or engine manual).
D If the engine is warm, checking is needed, and there is no overflow tank, follow the next two statements.
D Wear safety glasses and gloves and put a rag over radiator cap.
D Turn cap slightly and let pressure escape slowly before
completely removing cap.
FUEL can cause fire or explosion.
D
D
D
D
D Stop engine and let it cool off before checking or
adding fuel.
D Do not add fuel while smoking or if unit is near
any sparks or open flames.
Do not overfill tank — allow room for fuel to expand.
Do not spill fuel. If fuel is spilled, clean up before starting engine.
Dispose of rags in a fireproof container.
Always keep nozzle in contact with tank when fueling.
Using a generator indoors CAN KILL
YOU IN MINUTES.
MOVING PARTS can injure.
D Generator exhaust contains carbon monoxide.
This is a poison you cannot see or smell.
D NEVER use inside a home or garage, EVEN IF
doors and windows are open.
D Only use OUTSIDE and far away from windows, doors, and
vents.
D Keep away from moving parts such as fans,
belts, and rotors.
D Keep all doors, panels, covers, and guards
closed and securely in place.
D Stop engine before installing or connecting unit.
D Have only qualified persons remove doors, panels, covers, or
guards for maintenance and troubleshooting as necessary.
D To prevent accidental starting during servicing, disconnect
negative (−) battery cable from battery.
D Keep hands, hair, loose clothing, and tools away from moving
parts.
D Reinstall doors, panels, covers, or guards when servicing is
finished and before starting engine.
D Before working on generator, remove spark plugs or injectors to
keep engine from kicking back or starting.
D Block flywheel so that it will not turn while working on generator
components.
BATTERY ACID can BURN SKIN and EYES.
D Do not tip battery.
D Replace damaged battery.
D Flush eyes and skin immediately with water.
ENGINE HEAT can cause fire.
D Do not locate unit on, over, or near combustible
surfaces or flammables.
D Keep exhaust and exhaust pipes way from
flammables.
1-4. Compressed Air Hazards
D Do not work on compressed air system with unit running unless
you are a qualified person and following the manufacturer’s instructions.
D Do not modify or alter compressor or manufacturer-supplied
equipment. Do not disconnect, disable, or override any safety
equipment in the compressed air system.
D Use only components and accessories approved by the manufacturer.
D Keep away from potential pinch points or crush points created by
equipment connected to the compressed air system.
D Do not work under or around any equipment that is supported only
by air pressure. Properly support equipment by mechanical
means.
COMPRESSED AIR EQUIPMENT can
injure or kill.
D Incorrect installation or operation of this unit
could result in equipment failure and personal
injury. Only qualified persons should install, operate, and service this unit according to its
Owner’s Manual, industry standards, and national, state, and local codes.
D Do not exceed the rated output or capacity of the compressor or
any equipment in the compressed air system. Design compressed
air system so failure of any component will not put people or property at risk.
D Before working on compressed air system, turn off and lockout/
tagout unit, release pressure, and be sure air pressure cannot be
accidentally applied.
132
HOT METAL from air arc cutting and
gouging can cause fire or explosion.
MOVING PARTS can injure.
D Keep away from moving parts such as fans,
belts and rotors.
D Keep all doors, panels, covers, and guards
closed and securely in place.
D Do not cut or gouge near flammables.
D Watch for fire; keep extinguisher nearby.
D Keep hands, hair, loose clothing, and tools away from moving
parts.
D Before working on compressed air system, turn off and lockout/
tagout unit, release pressure, and be sure air pressure cannot be
accidentally applied.
COMPRESSED AIR can injure or kill.
D Before working on compressed air system,
turn off and lockout/tagout unit, release pressure, and be sure air pressure cannot be accidentally applied.
D Relieve pressure before disconnecting or connecting air lines.
D Have only qualified people remove guards or covers for maintenance and troubleshooting as necessary.
D Reinstall doors, panels, covers, or guards when servicing is
finished and before starting engine.
D Check compressed air system components
and all connections and hoses for damage,
leaks, and wear before operating unit.
D Do not direct air stream toward self or others.
D Wear protective equipment such as safety glasses, hearing protection, leather gloves, heavy shirt and trousers, high shoes, and
a cap when working on compressed air system.
D Use soapy water or an ultrasonic detector to search for
leaks−−never use bare hands. Do not use equipment if leaks are
found.
D Reinstall doors, panels, covers, or guards when servicing is
finished and before starting unit.
D If ANY air is injected into the skin or body seek medical help immediately.
HOT PARTS can burn.
D Do not touch hot compressor or air system
parts.
D Allow cooling period before working on equipment.
D To handle hot parts, use proper tools and/or
wear heavy, insulated welding gloves and
clothing to prevent burns.
BREATHING COMPRESSED AIR can injure or kill.
READ INSTRUCTIONS.
D Do not use compressed air for breathing.
D Use only for cutting, gouging, and tools.
D Read and follow all labels and the Owner’s
Manual carefully before installing, operating, or
servicing unit. Read the safety information at
the beginning of the manual and in each
section.
D Use only genuine replacement parts from the manufacturer.
D Perform maintenance and service according to the Owner’s
Manuals, industry standards, and national, state, and local
codes.
TRAPPED AIR PRESSURE AND WHIPPING
HOSES can injure.
D Release air pressure from tools and system before servicing, adding or changing attachments, or opening compressor oil drain or oil fill
cap.
1-5. Additional Symbols For Installation, Operation, And Maintenance
FIRE OR EXPLOSION hazard.
OVERHEATING can damage motors.
D Turn off or unplug equipment before starting or
stopping engine.
D Do not let low voltage and frequency caused by
low engine speed damage electric motors.
D Do not connect 50 or 60 Hertz motors to the 100 Hertz receptacle
where applicable.
D Do not install or place unit on, over, or near
combustible surfaces.
D Do not install unit near flammables.
D Do not overload building wiring − be sure power supply system is
properly sized, rated, and protected to handle this unit.
FALLING EQUIPMENT can injure.
FLYING SPARKS can injure.
D Use lifting eye to lift unit and properly installed
accessories only, NOT gas cylinders. Do not
exceed maximum lift eye weight rating (see
Specifications).
D Wear a face shield to protect eyes and face.
D Shape tungsten electrode only on grinder with
proper guards in a safe location wearing proper
face, hand, and body protection.
D Use equipment of adequate capacity to lift and support unit.
D If using lift forks to move unit, be sure forks are long enough to
extend beyond opposite side of unit.
D Keep equipment (cables and cords) away from moving vehicles
when working from an aerial location.
D Sparks can cause fires — keep flammables away.
MOVING PARTS can injure.
D Follow the guidelines in the Applications Manual for the Revised
NIOSH Lifting Equation (Publication No. 94−110) when manually lifting heavy parts or equipment.
OM-
D Keep away from moving parts.
D Keep away from pinch points such as drive
rolls.
133
BATTERY CHARGING OUTPUT and BATTERY
EXPLOSION can injure.
STATIC (ESD) can damage PC boards.
D Put on grounded wrist strap BEFORE handling
boards or parts.
D Use proper static-proof bags and boxes to
store, move, or ship PC boards.
Battery charging not present on all models.
D
D
D
D
D
D
D Always wear a face shield, rubber gloves, and
protective clothing when working on a battery.
Stop engine before disconnecting or connecting battery cables,
battery charging cables (if applicable), or servicing battery.
Do not allow tools to cause sparks when working on a battery.
Do not use welder to charge batteries or jump start vehicles unless it has a battery charging feature designed for this purpose.
Observe correct polarity (+ and −) on batteries.
Disconnect negative (−) cable first and connect it last.
Keep sparks, flames, cigarettes, and other ignition sources
away from batteries. Batteries produce explosive gases during
normal operation and when being charged.
TILTING OF TRAILER can injure.
D Use tongue jack or blocks to support weight.
D Properly install welding generator onto trailer
according to instructions supplied with trailer.
READ INSTRUCTIONS.
D Read and follow all labels and the Owner’s
Manual carefully before installing, operating, or
servicing unit. Read the safety information at
the beginning of the manual and in each
section.
D Use only genuine replacement parts from the manufacturer.
D Perform maintenance and service according to the Owner’s
Manuals, industry standards, and national, state, and local
codes.
D Follow battery manufacturer’s instructions when working on or
near a battery.
D Have only qualified persons do battery charging work.
D If battery is being removed from a vehicle for charging, disconnect negative (−) cable first and connect it last. To prevent an arc,
make sure all accessories are off.
D Charge lead-acid batteries only. Do not use battery charger to
supply power to an extra-low-voltage electrical system or to
charge dry cell batteries.
D Do not charge a frozen battery.
H.F. RADIATION can cause interference.
D Do not use damaged charging cables.
D Do not charge batteries in a closed area or where ventilation is
restricted.
D Do not charge a battery that has loose terminals or one showing
damage such as a cracked case or cover.
D
D Before charging battery, select correct charger voltage to match
battery voltage.
D Set battery charging controls to the Off position before connecting to battery. Do not allow battery charging clips to touch each
other.
D Keep charging cables away from vehicle hood, door, or moving
parts.
D
D
D
D High-frequency (H.F.) can interfere with radio
navigation, safety services, computers, and
communications equipment.
D Have only qualified persons familiar with
electronic equipment perform this installation.
The user is responsible for having a qualified electrician
promptly correct any interference problem resulting from the
installation.
If notified by the FCC about interference, stop using the
equipment at once.
Have the installation regularly checked and maintained.
Keep high-frequency source doors and panels tightly shut, keep
spark gaps at correct setting, and use grounding and shielding to
minimize the possibility of interference.
ARC WELDING can cause interference.
WELDING WIRE can injure.
D Do not press gun trigger until instructed to do
so.
D Do not point gun toward any part of the body,
other people, or any metal when threading
welding wire.
D
D
D
OVERUSE can cause OVERHEATING.
D
D Allow cooling period; follow rated duty cycle.
D Reduce current or reduce duty cycle before
starting to weld again.
D Do not block or filter airflow to unit.
D
134
D Electromagnetic energy can interfere with
sensitive electronic equipment such as microprocessors, computers, and computer-driven
equipment such as robots.
Be sure all equipment in the welding area is electromagnetically
compatible.
To reduce possible interference, keep weld cables as short as
possible, close together, and down low, such as on the floor.
Locate welding operation 100 meters from any sensitive electronic equipment.
Be sure this welding machine is installed and grounded
according to this manual.
If interference still occurs, the user must take extra measures
such as moving the welding machine, using shielded cables,
using line filters, or shielding the work area.
1-6. California Proposition 65 Warnings
Welding or cutting equipment produces fumes or gases
which contain chemicals known to the State of California to
cause birth defects and, in some cases, cancer. (California
Health & Safety Code Section 25249.5 et seq.)
Battery posts, terminals and related accessories contain lead
and lead compounds, chemicals known to the State of
California to cause cancer and birth defects or other
reproductive harm. Wash hands after handling.
For Gasoline Engines:
Engine exhaust contains chemicals known to the State of
California to cause cancer, birth defects, or other reproductive harm.
For Diesel Engines:
Diesel engine exhaust and some of its constituents are
known to the State of California to cause cancer, birth
defects, and other reproductive harm.
This product contains chemicals, including lead, known to
the state of California to cause cancer, birth defects, or other
reproductive harm. Wash hands after use.
1-7. Principal Safety Standards
Safety in Welding, Cutting, and Allied Processes, ANSI Standard Z49.1,
is available as a free download from the American Welding Society at
http://www.aws.org or purchased from Global Engineering Documents
(phone: 1-877-413-5184, website: www.global.ihs.com).
Safe Practices for the Preparation of Containers and Piping for Welding
and Cutting, American Welding Society Standard AWS F4.1, from Global Engineering Documents (phone: 1-877-413-5184, website:
www.global.ihs.com).
Safe Practices for Welding and Cutting Containers that have Held Combustibles, American Welding Society Standard AWS A6.0, from Global
Engineering Documents (phone: 1-877-413-5184,
website: www.global.ihs.com).
National Electrical Code, NFPA Standard 70, from National Fire Protection Association, Quincy, MA 02269 (phone: 1-800-344-3555, website:
www.nfpa.org and www. sparky.org).
Safe Handling of Compressed Gases in Cylinders, CGA Pamphlet P-1,
from Compressed Gas Association, 14501 George Carter Way,
Suite 103, Chantilly, VA 20151 (phone: 703-788-2700,
website:www.cganet.com).
Safety in Welding, Cutting, and Allied Processes, CSA Standard
W117.2, from Canadian Standards Association, Standards Sales, 5060
Spectrum Way, Suite 100, Ontario, Canada L4W 5NS (phone:
800-463-6727, website: www.csa-international.org).
Battery Chargers, CSA Standard C22.2 NO 107.2−01, from Canadian
Standards Association, Standards Sales, 5060 Spectrum Way, Suite
100, Ontario, Canada L4W 5NS (phone: 800-463-6727, website:
www.csa-international.org).
Safe Practice For Occupational And Educational Eye And Face Protection, ANSI Standard Z87.1, from American National Standards Institute,
25 West 43rd Street, New York, NY 10036 (phone: 212-642-4900, website: www.ansi.org).
Standard for Fire Prevention During Welding, Cutting, and Other Hot
Work, NFPA Standard 51B, from National Fire Protection Association,
Quincy, MA 02269 (phone: 1-800-344-3555, website: www.nfpa.org.)
OSHA, Occupational Safety and Health Standards for General Industry, Title 29, Code of Federal Regulations (CFR), Part 1910, Subpart Q,
and Part 1926, Subpart J, from U.S. Government Printing Office, Superintendent of Documents, P.O. Box 371954, Pittsburgh, PA 15250-7954
(phone: 1-866-512-1800) (there are 10 OSHA Regional Offices—
phone for Region 5, Chicago, is 312-353-2220, website:
www.osha.gov).
Portable Generators Safety Alert, U.S. Consumer Product Safety Commission (CPSC), 4330 East West Highway, Bethesda, MD 20814
(phone: 301-504-7923, website: www.cpsc.gov/cpscpub/pubs/portgen.pdf).
Applications Manual for the Revised NIOSH Lifting Equation, The National Institute for Occupational Safety and Health (NIOSH), 1600
Clifton Rd, Atlanta, GA 30333 (phone: 1-800-232-4636, website:
www.cdc.gov/NIOSH).
1-8. EMF Information
Electric current flowing through any conductor causes localized electric
and magnetic fields (EMF). The current from arc welding (and allied processes including spot welding, gouging, plasma arc cutting, and
induction heating operations) creates an EMF field around the welding
circuit. EMF fields may interfere with some medical implants, e.g. pacemakers. Protective measures for persons wearing medical implants
have to be taken. For example, restrict access for passers−by or conduct individual risk assessment for welders. All welders should use the
following procedures in order to minimize exposure to EMF fields from
the welding circuit:
1. Keep cables close together by twisting or taping them, or using a
cable cover.
2. Do not place your body between welding cables. Arrange cables
to one side and away from the operator.
3. Do not coil or drape cables around your body.
OM-
135
4. Keep head and trunk as far away from the equipment in the
welding circuit as possible.
5. Connect work clamp to workpiece as close to the weld as
possible.
6. Do not work next to, sit or lean on the welding power source.
7. Do not weld whilst carrying the welding power source or wire
feeder.
About Implanted Medical Devices:
Implanted Medical Device wearers should consult their doctor and the
device manufacturer before performing or going near arc welding, spot
welding, gouging, plasma arc cutting, or induction heating operations.
If cleared by your doctor, then following the above procedures is recommended.
THINK
Accident Bring
Tears,
Safety Brings
Cheers
136
MIG PARAMETERS
137
A GUIDE TO EFFECTIVE MIG / MAG WELDING
Binzel‟s motto of „bringing welding to the point‟ is dependent on the
following important factors
WELDING PARAMETERS
WIRE ELECTRODE
WELDING
1. Welding current
1. Shape & diameter
1. Wire Feeder
2. Cooling/shielding Gas
2. Wire surface
2. Welding Torch
EQUIPMENT
3. Winding on spool
Liner
Contact Tip
NOTE : The quality and the productivity of the welding operation is
influenced by each of the factors mentioned above. A good
welding torch alone cannot guarantee excellent & troublefree welding!
THE WELDING PARAMETERS
• The welding parameters are based entirely on the nature of the
welding job. Use of the optimum current and the correct mixture of
gases give a clean and porosity-free weld.
138
THE WIRE ELECTRODE
• The quality of the Wire Electrode plays a very important role in
giving a smooth feeding of the wire to the point of welding resulting in
uninterrupted welding cycles.
• The Wire Electrode must have –
• A smooth surface. Rough surface increases friction with Liner. It
also reduces transfer of current from Contact Tip to electrode.
Rough surface is normally due to manufacture of wires from wornout drawing dies.
• Proper coiling of the wire on spool. Coiling should be uniform,
otherwise it places excessive load on Wire Feeder during feeding
of wire. Larger spool diameter is better as it ensures that the wire
is straighter.
• Proper packing and storage of the wire is important. Unprotected
wire tends to get corroded / oxidized on the surface. This
increases wire diameter and also reduces conductivity of the wire.
• The Wire Electrode must have • A clean surface. Residue of oil or water on the wire reduces the
conductivity of the wire and increases the thermal load on Contact
Tip. This finally results in early failure of Contact Tip.
• A uniform diameter and shape throughout the length. Variation
in
size / shape adversely affects wire feeding and current
transmission.
139
• A proper coating for copper coated wires. Poor coating tends to
peel-off. These copper particles then get transported to
the
Contact Tip where they melt and stick to the opening. This results
in clogging of the tip.
THE WIRE FEEDER
The Wire Feeder performs the task of drawing Wire Electrode from the
spool and feeding it through the Liner to the point of welding. The
important factors to be monitored on a Wire Feeder are –
• Selection of the right type of feed rolls –
“V” groove for hard wires / “U” groove for Aluminium wires
• Selection of the right diameter of feed rolls –
Dia. 30 mm for low wire speed / Dia. 40 mm for 33% higher wire
speed
• Selection of optimum feed roll pressure on wire –
Too less pressure may result in erratic feeding of wire.
Excessive pressure may lead to deformation of wire, which may then
hamper smooth movement of wire through the Liner and Contact Tip.
140
THE WELDING TORCH
Whilst the entire design and construction of the welding torch is
extremely critical, the welder needs to pay special attention to two
elements of the torch – namely the Liner and the Contact Tip.
THE LINER
The Liner performs the important task of transporting the Wire Electrode
to the point of welding. The Liner must be –
• Of the right material to suit the material of the wire ( steel Liner for
low alloy wire / plastic Liner for Aluminium wire / S.S. Liner for high
alloy wire ).
• Of the right internal diameter to suit the wire diameter.
• Clean from inside. Copper coating / oxidation layer / corrosion layer /
grease and dust layer off the surface ofthe wire can clog the Liner.
• Free of „kinks‟ along the entire length and free of „burrs‟ at both
ends of the Liner. These kinks/ burrs act as obstacles to free
movement of the wire.
• Of the correct length. The length should be such that the Liner is
automatically pre-stressed after assembly on torch.
Abicor Binzel produces high quality Liners which are made from high
tensile strength steel all these factors determine the friction (or
resistance to movement) between the Liner and the Wire Electrode.
Excessive friction causes variation in feeding speed of the wire – leading
to poor welding quality.
141
THE CONTACT TIP
This is probably the most critical component in the welding torch. The
Contact Tip performs the most important task of transferring the
welding current (originating from power source and traveling through
cable) to the Wire Electrode.
For performing this task efficiently, the Contact Tip must –
• Be made of a material that has excellent conductivity, high wear
resistance and high thermal stability.
Abicor
Binzel
produces
Contact Tips from CuCrZr – which meets all these requirements.
CuCrZr is thermally stable up to 400 c whereas the more commonly
used E-Cu loses its thermal stability at around 250 c only.
• Have an accurately machined bore with excellent surface finish on
the internal surface of the bore. This ensures proper contact (over a
large surface area) between the wire and the Contact Tip. This in turn
ensures low heat generation at the Contact Tip and enhances the life
of Contact Tip.
• Only Abicor Binzel possesses the technology to drill these bores with
a high degree of precision. The process of „drawing‟ of hollow tubes
can never match the precision of our drilling process.
142
WISHING YOU A HAPPY
AND
SAFE WELDING
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement