25MP Direct Operated Pressure Regulator

25MP Direct Operated Pressure Regulator
INSTALLATION AND MAINTENANCE INSTRUCTIONS
October 2015
IM-3-104-US
25 MP Direct Operated Pressure Regulator
Safety Information
1.6 The system
Safe operation of these products can only be guaranteed if
they are properly installed, commissioned, used and maintained
by qualified personnel (see Section 1.11) in compliance with
the operating instructions. General installation and safety
instructions for pipeline and plant construction, as well as the
proper use of tools and safety equipment must also be complied
with.
Consider the effect on the complete system of the work
proposed. Will any proposed action (e.g. closing isolation
valves, electrical isolation) put any other part of the system or
any personnel at risk?
Dangers might include isolation of vents or protective devices
or the rendering ineffective of controls or alarms. Ensure
isolation valves are turned on and off in a gradual way to avoid
system shocks.
1.1 Intended use
Referring to the Installation and Maintenance Instructions,
name-plate and Technical Information Sheet, check that the
product is suitable for the intended use / application.
1.7 Pressure systems
Ensure that any pressure is isolated and safely vented to
atmospheric pressure. Consider double isolation (double block
and bleed) and the locking or labelling of closed valves. Do not
assume that the system has depressurised even when the
pressure gauge indicates zero.
i) The products have been specifically designed for use on
steam, air or water/condensate. The products’ use on other
fluids may be possible but, if this is contemplated, Spirax
Sarco should be contacted to confirm the suitability of the
product for the application being considered.
1.8 Temperature
Allow time for temperature to normalise after isolation to avoid
danger of burns.
ii) Check material suitability, pressure and temperature and
their maximum and minimum values. If the maximum
operating limits of the product are lower than those of the
system in which it is being fitted, or if malfunction of the
product could result in a dangerous overpressure or
overtemperature occurrence, ensure a safety device is
included in the system to prevent such over-limit situations.
1.9 Tools and consumables
Before starting work ensure that you have suitable tools and / or
consumables available. Use only genuine Spirax Sarco
replacement parts.
1.10 Protective clothing
iii) Determine the correct installation situation and direction
of fluid flow.
Consider whether you and / or others in the vicinity require any
protective clothing to protect against the hazards of, for example,
chemicals, high / low temperature, radiation, noise, falling
objects, and dangers to eyes and face.
iv) Spirax Sarco products are not intended to withstand external
stresses that may be induced by any system to which they
are fitted. It is the responsibility of the installer to consider
these stresses and take adequate precautions to minimise
them.
1.11 Permits to work
All work must be carried out or be supervised by a suitably
competent person. Installation and operating personnel should
be trained in the correct use of the product according to the
Installation and Maintenance Instructions.
v) Remove protection covers from all connections and
protective film from all name-plates, where appropriate,
before installation on steam or other high temperature
applications.
Where a formal ‘permit to work’ system is in force it must be
complied with. Where there is no such system, it is recommended
that a responsible person should know what work is going on
and, where necessary, arrange to have an assistant whose
primary responsibility is safety.
1.2 Access
Ensure safe access and if necessary a safe working platform
(suitably guarded) before attempting to work on the product.
Arrange suitable lifting gear if required.
Post ‘warning notices’ if necessary.
1.3 Lighting
1.12 Handling
Ensure adequate lighting, particularly where detailed or intricate
work is required.
Manual handling of large and/or heavy products may present
a risk of injury. Lifting, pushing, pulling, carrying or supporting
a load by bodily force can cause injury particularly to the back.
You are advised to assess the risks taking into account the
task, the individual, the load and the working environment and
use the appropriate handling method depending on the
circumstances of the work being done.
1.4 Hazardous liquids or gases in the pipeline
Consider what is in the pipeline or what may have been in the
pipeline at some previous time. Consider: flammable materials,
substances hazardous to health, extremes of temperature.
1.5 Hazardous environment around the product
Consider: explosion risk areas, lack of oxygen (e.g. tanks, pits),
dangerous gases, extremes of temperature, hot surfaces, fire
hazard (e.g. during welding), excessive noise, moving
machinery.
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1.13 Residual hazards
Steam Mains - Do's and Dont's:
In normal use the external surface of the product
may be very hot. If used at the maximum
permitted operating conditions the surface
temperature of some products may reach
temperatures in excess of 300°C (572°F).
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Many products are not self-draining. Take due
care when dismantling or removing the product
from an installation (refer to 'Maintenance
instructions').
1.14 Freezing
Provision must be made to protect products
which are not self-draining against frost
damage in environments where they may be
exposed to temperatures below freezing point.
Steam
1.15 Disposal
Unless otherwise stated in the Installation
and Maintenance Instructions, this product
is recyclable and no ecological hazard is
anticipated with its disposal providing due
care is taken.
1.16 Returning products
Customers and stockists are reminded that
under EC Health, Safety and Environment Law,
when returning products to Spirax Sarco they
must provide information on any hazards and
the precautions to be taken due to contamination
residues or mechanical damage which may
present a health, safety or environmental risk.
This information must be provided in writing
including Health and Safety data sheets relating
to any substances identified as hazardous or
potentially hazardous.
1.17 Working safely with cast iron
products on steam
Cast iron products are commonly found on
steam and condensate systems. If installed
correctly using good steam engineering
practices, it is perfectly safe. However, because
of its mechanical properties, it is less forgiving
compared to other materials such as SG iron or
carbon steel. The following are the good
engineering practices required to prevent
waterhammer and ensure safe working
conditions on a steam system.
Prevention of tensile stressing
Pipe misalignment:
Installing products or re-assembling after maintenance:
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Safe Handling
Cast Iron is a brittle
material. If the product
is dropped during
installation and there
is any risk of damage
the product should
not be used unless it
is fully inspected and
pressure tested by the
manufacturer.
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Do not over tighten.
Use correct torque figures.
Prevention of water hammer
Steam trapping on steam mains:
30 - 50 metre intervals
Gradient
Steam
1:100
Trap set
Condensate
Gradient
1:100
Trap set
Condensate
Steam
Trap set
Condensate
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3
2
1
3
5
6
4
2
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Flange bolts should be gradually tightened across
diameters to ensure even load and alignment.
Thermal expansion:
Guides
Limit rods
Guides
Medium
distance
Axial movement
Short
distance
Small
lateral
movement
Large
lateral
movement
Fixing point
Fixing point
Limit rods
Axial movement
Guides
Large
lateral
movement
Small
lateral
movement
Guides
Installation
5
The 25 MP is best installed in a horizontal line with the adjustment screw at the top. A strainer before the valve will protect
it from line dirt. Fit the strainer on its side and ensure adequate
clearance for screen removal. Use fullway pattern isolating
valves and piping of adequate size to carry the steam flow. A
downstream pressure sensing connection must be made to
the port on the lower diaphragm housing as shown. Copper
tubing 5/16” O.D. is preferred, with a 1/4” steel pipe as an
alternative.
The 25 MP control will give long, trouble free service when
correctly installed and kept reasonably free from dirt or other
foreign matter. These mostly collect during installation. Avoid
later troubles by inspecting the installation a few days after
commissioning.
1. Clean all pipeline strainers (remove screens to clean).
2. Check the valve seat.
3. Check all joints for tightness.
Caution: Before installation or any maintenance is performed,
insure that all steam lines are closed to prevent injury.
Start-up
my be necessary to make a pressure readjustment. Repeat
procedure 4 if required. Replace spring cover, then tighten
adjustment locknut.
1. First make certain that all stop valves are closed.
2. Loosen locknut. Remove pilot spring cover, then turn the
pressure pilot adjustment (5) counterclockwise until spring
is slack. Make certain spring remains in vertical position
and centered in its retainers.
3. Open stop valves in the following order:
a. Open stop valve ahead of steam trap on
steam supply line. This will insure
condensate-free steam at the
regulator inlet when put into
Vent to
operation.
Atmosphere
b. Isolate pressure sensing line.
c. Slowly open inlet stop valve.
4. Slowly adjust pilot by turning the
pressure adjustment bolt (5) clockwise until reduced pressure required
is indicated on pressure gauge
downstream of valve.
7. IMPORTANT - Retighten flange connection to body to
ensure steam tight joints, after 24 hours operation.
Torque 20 lb/ft.
10 Pipe
Diameters
Minimum
Safety
Valve
Steam
Supply
Direct
Operated
Pressure
Reducing Valve
Pressure
Sensing Line
Pitch Down
Strainer
Reduced
Steam Pressure
Thermo-Dynamic®
Steam Trap
5. Slowly open downstream stop valve.
6. Once the system has stabilized, it
Strainer
Spira-tec
Loss Detector
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Maintenance and Repair
The pressure control spring is replaceable by removing the
aluminum cover and turning the adjustment (5) counterclockwise. After fitting new spring, insure that spring support discs
are properly located and the adjustment (5) is entered in the
center hole of the support disc. Valve assembly is supplied as
a set. A new gasket supplied with each set should be fitted to
insure a steam tight seal. Insure gasket faces are clean and
free from deposits before refitting.
G4
B4
A4
Stem guide and gasket set are replaceable after removing the
upper housing, first remove the control spring as described
above. To obtain access to the stem guide, removal of the diaphragm is necessary. The diaphragm is sandwiched between
the upper and lower housing to provide a flexible seal. Since it
forms a pressurized steam joint, replacement of the diaphragm
is recommended if this joint is broken.
F4
H4
K4
J4
L4
Spare Parts
B
Available Spare
Part No.
Cover Plate with Retaining Ring
K4
Diaphragm Assembly
L4
Stem Guide with Gasket
T4
S4
M4, N4
Head and Seat Assembly with Gasket
Pilot Screws and Gasket
W
G4, H4, J4
Adjustment Spring (specify range)
Square Gasket
N4
A4, B4
Adjustment Screw with nut and, upper and lower
spring support disc
M4
S4, T4
W
B, W
Spirax Sarco Applications Engineering Department
Toll Free at:
1-800-575-0394
SPIRAX SARCO, INC. • 1150 NORTHPOINT BLVD. • BLYTHEWOOD, SC 29016
PHONE 803-714-2000 • FAX 803-714-2200
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