Combination Pilot Operated Regulators Types 25PT

Combination Pilot Operated Regulators Types 25PT
INSTALLATION AND MAINTENANCE INSTRUCTIONS
IM-3-017-US
October 2015
Combination Pilot Operated Regulators
Types 25PT, 25PE, 25TE & 25PTE
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.
1
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).
4
7
4
7
4
7
4
7
4
7
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:
1
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.
4
7
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
2
7
3
2
1
3
5
6
4
2
8
Flange bolts should be gradually tightened across
diameters to ensure even load and alignment.
Thermal expansion:
Guides
Guides
Medium
distance
Axial movement
Short
distance
Small
lateral
movement
Limit rods
Large
lateral
movement
Fixing point
Fixing point
Limit rods
Axial movement
Guides
Small
lateral
movement
Guides
IMPORTANT: Read carefully the instructions for both
the valve and control pilots before installing the regulator.
4.Before installing the valve, be sure the piping is free of
foreign material, scale, etc.
5.Make certain the arrow cast on the valve body is pointing in the direction of flow.
Installing the Valve
Unpack Carefully
6.Valve should always be installed in a horizontal line.
(See Fig. 1).
Do not lift the regulator by the flexible tubing or control
pilot. Grasp the body of the main valve firmly when lifting.
Do not bend sharply or kink the flexible tubing. The valve
is completely assembled with the exception of the pressure
pilot sensing line fittings.
Bypass
1.A bypass connection is recommended so that the valve
can be serviced without shutting down the equipment.
Valve Piping
2.The bypass valve should be the same size as the pressure temperature regulator.
1.A typical hookup sketch as shown in Fig. 1 will aid in
planning a correct installation.
Steam Line Drain Trap
2.Piping on the downstream side of the valve should be
sized properly so as not to restrict steam flow.
To insure proper operation of the valve and avoid premature wear, it is recommended that a steam trap be installed
on the steam supply line. (See Fig. 1).
3.Swage nipples are recommended for changes in pipe
sizes.
Safety
Valve
Strainer
Moisture
Separator
Vacuum
Breaker
Drip Pan
Elbow
Pilot Operated
Pressure/Temperature
Control Valve
Sensor
Steam
Supply
Heat Exchanger
Float &
Thermostatic
Steam Trap
Large
lateral
movement
Spira-tec
Loss
Detector
Cold
Water
Supply
Fig. 1
Combined Pressure and Temperature Control of Heat Exchanger
3
Gravity
Return
Spira-tec
Loss
Detector
Float &
Thermostatic
Steam Trap
Strainer
Pipeline Strainers
Thermostatic Bulb and Tubing
2.Make certain adequate clearance is provided for
screen removal and blowdown connection between
strainer and regulating valve body.
3.Keep flexible tubing away from hot pipe lines or other
hot surfaces.
1.Carefully uncoil the flexible tubing avoiding sharp
bends and kinks.
2.Support flexible tubing to protect it against mechanical
damage.
1.It is strongly recommended that strainers be installed
before the pressure temperature regulating valve and
steam traps. (See Fig. 1)
Stop Valves
4.Attach thermostatic bulb to unit to be controlled. Make
certain that the entire bulb is exposed to the medium
being controlled. Accuracy of regulation depends on
the bulb being located in a representative location with
adequate circulation over it.
Electric Pilot Wiring, Type PE/TE/PTE
5.If a separable socket is used for the temperature bulb,
it is recommended that the socket be packed with a
heat transfer compound to minimize lag in response to
temperature changes caused by the insulating air layer
between bulb and socket.
All stop valves on the supply side, as well as on the downstream side of the pressure temperature regulating valve,
should be of the gate type so as to insure full rated capacity and good control.
1.Check nameplate on electric pilot for correct voltage
and service conditions.
2.Wiring must comply with local and national electrical
codes.
How it Works
3.Solenoid enclosure is provided with hole to accommodate standard 1/2 inch conduit connection.
Normal positions before startup are with the main valve
and electric pilot closed, pressure pilot open, and temperature pilot open. On startup, entering steam passes in
series through all pilot valves into the diaphragm chamber
and out through the control orifice. As flow through the
pilot valves exceeds flow through the orifice, control pressure increases in the main diaphragm chamber, and that
opens the main valve.
4.The solenoid enclosure can be rotated to facilitate wiring by loosening the cap nut. (See Fig. 6).
Pressure Pilot Sensing Line, Type PT/PE/
PTE
1.Copper tubing (5/16” OD) can be used for the sensing
line with suitable compression fittings or as an alternative 1/4” piping can be used.
Electric Pilot
Functions as an on/off override to the other pilots. When
it is energized and open, the pressure or temperature pilot
regulates any change in steam flow required.
2.Connect the sensing line to a straight portion of the piping 10 pipe diameters from nearest fitting downstream
from the valve and approximately 1 foot from elbows,
tees, valves and other restrictions. (See Fig. 1).
Pressure Pilot
As steam flows through the main valve, the increase in
downstream pressure feeds back through the pressure
sensing line to the underside of the pressure diaphragm.
When force below that diaphragm balances the compression force of the spring above it, the pressure pilot valve
throttles. Control pressure in the main diaphragm chamber
positions the main valve so that maximum steam pressure
will not be exceeded.
3.When the pressure temperature regulator is serving
a single piece of equipment, the pilot line can be connected to the steam space of the equipment.
4.Install a small gate valve in the pilot line so that this
can be closed when servicing the regulator.
Temperature Pilot
As the medium being heated approaches the desired temperature, liquid in the bulb expands through the capillary
tubing into the bellows and throttles the temperature pilot
valve. The pilot valve delivers just enough steam to the
main diaphragm chamber to provide steam flow through
the main valve to maintain pre-set temperature.
5.The control line must be pitched downward from the
main valve to insure proper drainage.
6.To permit accurate setting of the pressure regulator, a
pressure gauge should be installed as close as possible to the pilot line connection.
Temperature Pilot, Type PT/TE/PTE
When no steam is required. The main valve closes tight
to provide dead-end shut off. The temperature setting can
be changed by turning the calibrated adjustment dial. The
maximum delivery pressure can be changed by adjusting
the pressure pilot spring.
Depending upon the installation, the position of the calibrated dial of the pilot, as received, may not be easily
observed by the operating personnel. To change the calibrated dial position, loosen hexagon nut (K), (Fig. 3) and
rotate the entire adjustment assembly to a position that can
be easily observed. Retighten hexagon nut (K).
4
­ tart-Up
S
1.First make certain that all stop valves are closed. The
electric pilot must be energized open.
2.Unscrew solenoid housing nut and remove housing, coil
and housing base plate.
3.Base assembly (4J) is now accessible for removal with
hexagon or adjustable open end wrench.
2.Turn the pressure pilot adjustment 2D (Fig. 3) counterclockwise until spring is slack.
4.Valve head, spring and seat are now accessible
for inspection, cleaning and replacement, if necessary. When replacing seat, use compound on threads
(remove excess). Tighten to 75 in./lb. torque.
3.Adjust the temperature pilot to the temperature
required by turning the red adjustment knob 3C.
Caution: Do not loosen Allen set screw in the red
temperature knob.
Temperature Pilot, Inspecting and Replacing
Valve Head and Seat (Refer to Fig. 3)
4. Open stop valves in the following order:
a.Open stop valve ahead of steam trap on steam
supply line. This will insure water free steam at the
regulator inlet when put into operation.
b.Open small gate valve on pressure sensing line.
c. Open downstream stop valve.
d. Slowly open inlet stop valve.
Note:Inspecting and replacing parts, if necessary, can be
done without removing the pilot from the main valve.
However, if more convenient, the entire pilot can be
removed from the main valve by removing the four
cap screws.
Exception: To replace the seat in low pressure
(15 psi and below) 2-1/2”, 3”, 4” and 6” valves, the
entire pilot must be removed from the main valve or
mounting bracket.
5.Slowly adjust pressure pilot spring at 2D turning clockwise until reduced pressure required is indicated on
pressure gauge downstream of valve.
1.Unscrew hexagon nut (K) and remove temperature
adjustment assembly.
2.The pilot valve head assembly (3E), which includes the
springs, Teflon seal, and valve head, can then be withdrawn and inspected.
6.After the system has stabilized itself, check thermometer temperature. Readjustment of the temperature
pilot (red knob 3C) may be necessary. Note: In the
event the temperature indicated on the calibrated dial
does not agree with the thermometer, the temperature
pilot can be recalibrated to match the thermometer as
described on page 6.
3.If it is found after inspection that the head is worn, the
entire assembly should be replaced. (Refer to Repair
Parts List P9-650).
4.The pilot valve seat can be removed for inspection
using a 1/2” hexagon socket wrench.
7.Important–Retighten all pilot flange connections to
insure steam tight joints.
5.If the seat shows signs of wear, the seat should be
replaced including a new seat gasket.
Maintenance
General Inspection
Pressure Pilot, Inspecting and Replacing
Valve Head and Seat (Refer to Fig. 3)
While a program of planned maintenance is always to be
recommended, the Spirax Sarco 25 series regulator will
give long and trouble-free service if correctly selected,
installed and kept reasonably free of dirt and foreign matter. Dirt and foreign matter are most likely to collect during
installation and later trouble can be avoided by inspecting
the installation after a few days. Check the following:
1.Remove 4 pressure pilot flange cap screws and lift off
pilot. Visual examination can then be made of the pilot
valve head and seat.
2.Pilot valve head and seat are contained in one complete
assembly. (See Fig. 3).
1. Clean all pipeline strainers.
3.To remove head and seat assembly (2H), unscrew
hexagon nut, using 11/16” hex wrench.
2.Check the main valve seat (1E) and protective screen
(1D).
4.If it is found that either the head or seat is worn, the
entire assembly should be replaced.
3. Inspect and clean orifices (B) and (H).
Inspecting and Replacing Pilot Head Stem
Guide (Refer to Fig. 3)
4. Check all joints for leakage.
Electric Pilot, Inspection of Solenoid and
Internal Parts (Refer to Fig. 6)
The important thing to check is to make sure that the pilot
head stem moves freely through the guide. This can be
determined by removing the complete pilot from the main
1.Shut off steam supply to valve and turn off electrical
power.
5
2. Remove pilot yoke (2B) and pilot diaphragm (2F).
8.If it is necessary to replace the valve seat, this can be
removed from the valve body using a standard hexagon socket. (Valve sizes 1/2” to 2”). When replacing
the valve seat, a new gasket should be used to insure
a tight joint. 2-1/2” thru 6” valves contain raised lugs
for removal and seal metal-to-metal without a gasket.
Replacement heads and seats should be lapped in.
3.The stem guide assembly can then be removed with a
7/8” hex socket wrench.
Valve Sizes 1/2” thru 4”
Inspecting and Replacing Pressure Pilot
Valve Diaphragms (Refer to Fig. 3)
1.Unscrew copper tubing connection at (G).
valve and turning adjustment (2D) so as to move the head
replacement to an open and closed position. Should
cleaning or replacement be required, proceed as follows:
1. Remove the pilot diaphragm cap screws (2C).
Inspecting and Replacing Main Valve
Diaphragms (Refer to Figs. 3, 4 and 5).
1.Turn adjustment screw (2D) counterclockwise until
spring is slack.
2. Remove main valve diaphragm bolts (1C).
3.This will allow the lower diaphragm case to be removed.
2.Remove cap screw (2C). Pilot yoke (2B) can then be
removed.
4.The 2 metal diaphragms (1H) should be inspected to
insure that they have not become distorted or possibly
fractured as a result of abnormal operating conditions.
3.The 2 metal diaphragms (1H) can then be inspected for
distortion or possible fracture as a result of abnormal
operation.
5.At the same time, any accumulation of dirt or foreign
material should be removed from the diaphragm case.
4.At the same time, any accumulation of dirt or foreign
material should be removed from the lower diaphragm
pilot case.
6.The valve stem (1F) should also be checked to make
sure it is free to move and that there is no scale or foreign material lodged in the guide bushing.
5.When replacing diaphragms, make certain casting surface is clean to insure a steam tight joint. Application
of a plastic compound on the casting surface, such as
Garlock 101, is recommended.
7.Before reassembling diaphragms in 1/2” thru 4”
sizes, main valve head must be in place and held in
a closed position with the return spring and main
valve cover.
6.Position pilot yoke on lower diaphragm pilot casting
making certain that the yoke is properly centered.
8.Make certain pressure plate (1G) is set properly. (Refer
to Fig. 4).
7. Tighten all cap screws uniformly.
9.Care should be taken in centering the diaphragms properly and equalizing bolt take-up uniformly.
Valve Sizes 1/2” thru 4”
Inspecting and Replacing Main Valve Head
and Seat (Refer to Figs. 3 and 5).
6” Valve Only
1.Unscrew copper tubings at (J) and (L).
2.Disconnect pressure control line at the pressure pilot
connection.
Inspecting and Replacing Main Valve
Diaphragms, Seat, and Head Assembly
(Refer to Fig. 7).
3. Remove main valve cover cap screws (1A).
Diaphragms
1.Unscrew copper tubing connections (G) to lower diaphragm chamber.
4.Remove main valve cover, strainer, screen, and head
spring.
2.Remove main valve diaphragm bolts (1C) and drop
lower diaphragm case.
5.Head can then be removed by simply withdrawing with
a pliers or similar tool.
3.The 2 metal diaphragms (1H) should be inspected and
replaced if they have become distorted or fractured.
6.Inspection should then be made to determine if scale
or other foreign material prevented tight closure of the
head and seat.
4.Clean any accumulation of dirt from the diaphragm
case and orifice (H).
7.If the head or seat shows signs of wear, this can be corrected by grinding, using a fine grinding compound (400
grit) providing the wear is not too severe. Check for
body erosion.
Servicing the Main Valve Head and Seat
5.Loosen the diaphragm plate set screw and remove the
diaphragm plate (1G).
6
6. Remove the top cover bolts (1A) and cover.
Note: For replacement parts refer to Spirax Sarco
Parts List P21.
7.Remove the stem and head assembly from the valve.
Inspect the head and seat for wear.
Size 1/2” & 3/4” 1” 1-1/4” & 1-1/2 2” 2-1/2” 3” 4”
Dim A 1/16” 5/64”
3/32”
1/8” 13/64” 13/64” 1/4”
8. Check for body erosion around the seat ring.
9.Replacement seats and heads should be lapped in,
and minor wear can also be corrected by lapping with
400 grit compound.
2D
3A
Recalibration of Temperature Adjustment
Dial
2B
M
The temperature adjustment dial can be recalibrated after
servicing or to match the calibration of a thermometer on
a particular application installed next to the temperature
bulb. To recalibrate, proceed as follows:
3E
3C
K
1D
1.The control bulb must be immersed in a temperature
within the range of the calibrated dial.
2F
2C
2G
2H
1A
B
J
2.With steam pressure on the valve, turn temperature
adjustment knob (3C) slowly clockwise until main valve
shuts off flow of steam.
L
1E
3.Turn temperature adjustment knob (3C) counterclockwise slightly, just enough to start a slight flow of steam.
1F
4.Loosen small Allen set screw in red temperature
adjustment knob (3C) using a 3/32” hex Allen set
screw wrench and pull know upwards off its rubber
support.
1G 1H
5.Rotate red temperature knob until temperature on dial
matches temperature reading at the control bulb, then
push knob downwards over the rubber support.
Fig. 3
Sizes 1/2” to 2”
6.Retighten Allen set screw. Note: No attempt should
be made to recalibrate the temperature pilot for temperatures beyond the range shown on the calibrated
dial. If the temperature range is to be changed, the
entire pilot assembly including the thermostatic systems must be replaced.
1C
H
G
Head on Seat
Replacement of Thermal System
1.Loosen hexagon nut (M) and withdraw thermostatic
bellows.
2.Insert replacement system in a similar manner making
certain to tighten hexagon nut (M). Caution: Do not
over-tighten.
Adjustment
& Locknut
3.All replacement systems are interchangeable for the
same range and generally readjustment of the temperature dial is not required. However, should this
be necessary, follow the instructions as described
under “Recalibration of Temperature Adjustment Dial,”
above.
Pressure Plate
1G
Fig. 4Note in 1/2” thru 4” sizes, top of valve must be
completely assembled and head must be on
seat when measuring dimension “A” and when
reassembling diaphragms.
7
1A
2D
2D
3A
2B
2F
M
3C
2C
2H
1D
J
B
K
2G
1A
1F
1E
1G 1H
L
B
G
1F
1G
Orifice
H
1C
1H
Fig. 7
6” Size
1C
H
G
Pressure Adjustment
Fig. 5
Sizes 2-1/2” to 4”
Control Spring
Pilot
Diaphragm
Downstream
Pressure
Sensing
Line
4-H
Pilot Valve
Head & Seat
Cap Nut
Orifice
4-K
Flow
4-J
Fig. 6
Electric Pilot
Main Valve
Head & Seat
4-G
Control
Pressure
8
Main Valve
Diaphragm
Troubleshooting
Refer to Figs. 3, 5, & 7
Symptom
Cause
Check and Cure
1. Controlled temperature 1. (a) Control not properly set. 1. (a)
or pressure overrides the set point.
(b) Thermo bulb not in representative (b)
location.
Adjust knob (3C) or (2D) to lower setting.
Check actual temperature at bulb with
glass thermometer. If necessary, relocate
bulb.
(c) Dirt under pilot valve (2H) or (3E) or (c)Set knob (3C) to temperature higher than
spindles sticking.bulb temperature. Remove tubing connection at (J). Loosen adj. (2D) until steam
flow from pilot body stops. Then tighten
(2D) slightly. Steam should flow. If not,
pilot (2H) must be removed and cleaned
or replaced. Tighten screw (2D) until
steam flows from body. Turn adj. (3C) to
temperature lower than bulb temperature.
Steam flow should stop. Alternately adjust
(3C) up and down. Steam flow should
alternately start and stop. If not, remove
(K) and clean or replace pilot head and
seat.
(d) Valve oversized.
(d)Check actual load against valve rating.
Reduce maximum outlet pressure by loosening screw (2D).
(e) Dirt in orifice (B) or (H), or (e) Inspect and clean.
pressure sensing line may be plugged.
(f) Dirt under main valve or valve head and (f) Set knob (3C) or (2D) to lowest setting.
seat worn.Disconnect tubing at (G). Valve should
close. If it doesn’t, remove bolts (1A) and
clean main valve.
(g) Defective thermal system. (g)Experience over the years has shown that
(RARE).failure of the thermal system (other than
mechanical damage) is very rare. Only
after all of the “checks” listed on the
troubleshooting chart have been pursued
should the following test be made to determine if the thermal system is defective.
i. Disconnect copper tubing connection at (J)
ii.Immerse thermal system bulb in a temperature 20° above dial setting. Allow
to saturate for approximately 5 minutes.
iii.Open steam supply stop valve to allow
steam to flow to temperature regulator.
iv.Under these conditions steam should
not flow from copper tubing connection
(J) which shows that the thermal system is satisfactory.
v.If steam should flow from tubing connection (J), exert pressure downward
with thumb on thermal system elbow
connection (3A). If this pressure seats
pilot valve head and stops steam flow,
the thermal system is probably defective.
9
Troubleshooting
(Continued)
Symptom
Cause
Check and Cure
2. Temperature too low 2. (a) Faulty electric pilot control circuit
2. (a) Check electrical system for correct
or valve does not open. or actuating device.
solenoid opening and closing by switch or
timer.
(b) Control not properly set.
(b) Adjust knob (3C) to higher setting.
3. Erratic Control
3. (a) Thermo bulb not in representative
3. (a) See 1. (b) above.
location.
.
(b) Heating surface may be waterlogged (b) Inspect and repair if necessary.
due to defective steam trap.
(c) Valve undersized.
(c)Check actual load against rating of valve.
Increase maximum delivery pressure by
tightening adj. (2D).
(d) Main valve diaphragm (1H) cracked. (d) Remove tubing at (G). Crack bypass
valve. If steam blows from diaphragm
case, replace diaphragms (1H).
(e) Orifice at (B) or (H) blocked.
(e) Inspect and clean.
(f) Supply steam pressure too low.
(f) Check and correct.
(g) Valve screen (1D) blocked. (g) Remove bolts (1A). Inspect strainer and
clean.
(h) Line strainer partially or completely
blocked.
(h) Inspect and clean.
(i) Pilot valve (2H) or (3E) sticking, dirty
or defective.
(i) See 1(c) above.
(j) Dirt or foreign material on main valve
stem and guide (1F).
(j) Remove, inspect and clean.
4. Delivery pressure too 4. (a) Valve not properly adjusted.
4. (a) Adjust screw (2D) to desired pressure.
low.
(b) Valve undersized. (b) Check actual load against valve rating.
(c) Upstream pressure too low.
(c) Check and correct.
(d) Main diaphragm leaking.
(d) See 2(d) above.
(e) Orifice (b) missing.
(e) Replace proper fitting.
5. Valve fails to close.
5. (a) Faulty electric pilot control circuit
or actuating device.
5. (a) See 2(a) above.
(b) Bypass valve open or leaking.
(c) Pilot sensing line blocked (or not
installed).
(b) Check and repair as required.
c) Remove, inspect, clean or install.
(d) Pressure pilot diaphragm ruptured (d) Replace pilot diaphragm assembly (2F).
(water or steam coming from pilot
at spring retainer area).
(e) Pilot assembly or main valve seat
threads leaking.
(f)
(e) Check casting in seat area for erosion.
Main valve diaphragms reassembled (f) With main valve cover installed, loosen
without return spring and main valve
all main valve diaphragm bolts (1C) and
cover holding valve head closed.
then retighten.
(1/2” thru 4” sizes only).
10
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
11
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