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V4730B/V8730B, V4750B/V8750B CLASS A DOUBLE BLOCK AND PRESSURE REGULATING SAFETY SHUTOFF VALVES
19. Remove the leak test tap from the valve body.
20. Using a small amount of pipe sealant on the 1/8 in.
(3 mm) NPT plug, reinstall the plug in pressure tap
point 4.
After the Test
1. Make sure the downstream manual gas cock (E) is
closed.
2. Open the upstream manual gas cock (A) and energize
the valve through the safety system.
3. Test with rich soap and water solution to make sure
there is no leak at the test tap (D) or any pipe
adapter/valve mating surfaces.
4. De-energize the valve C.
5. Open the downstream manual gas cock (E).
6. Restore the system to normal operation.
A
B
GAS
SUPPLY
SSOV
UPSTREAM
PRV
MANUAL
2
GAS COCK
CAN ALSO BE A PERMANENT PETCOCK.
1
2
PRV = PRESSURE REGULATING VALVE.
3
SSOV = SAFETY SHUTOFF VALVE.
4
USE THE DOWNSTREAM TAP ON THE SS0V.
Fig. 17. Valve leak test.
TROUBLESHOOTING
WARNING
Electrical Shock Hazard.
Can cause serious injury or death.
Use extreme caution while troubleshooting; line
voltage is present.
IMPORTANT
Do not replace the valve until all other sources of
trouble are eliminated.
Troubleshooting Procedure
If the valve does not open when the thermostat or controller
calls for heat:
65-0275—2
C
C
D
E
DOWNSTREAM
LEAK
MANUAL
TEST
4
GAS COCK
TAP
SSOV
3
F
1/4 IN. (6 MM)
FLEXIBLE
MANUAL
TUBING
TEST
PETCOCK
1/4 IN. (6 MM)
ALUMINUM OR
COPPER PILOT
JAR OR GLASS
TUBING
WITH WATER
1
(13 MM)
2
CUT AT
45 DEGREE
ANGLE
1. Check for line voltage at the valve leadwires or terminal
block.
2. If there is no voltage at the valve leadwires or terminal
block, make sure:
a. line voltage power is connected to the master
switch.
b. master switch is closed and overload protection
(circuit breaker, fuse or similar device) has not
opened the power line.
3. If there is still no voltage at the valve leadwires or
terminal block, make sure all appropriate contacts in the
thermostat or controller, limits and flame safeguard
controls are closed. If one or more are open, determine
the cause(s); correct the trouble and proceed.
4. If there is proper voltage at the valve but the valve still
does not open, check for normal gas pressure.
5. If the valve still does not open, replace the valve.
If the valve does not close when one or more of the
appropriate contacts in the thermostat, controller, limits or
flame safeguard control is open:
1. Make sure the valve is wired in the correct circuit.
2. Open the master switch to remove power from the
valve.
BURNER
3. If the valve closes now, check the wiring for the valve
and correct the wiring as necessary.
4. Check for a short in the electrical circuit and repair it as
necessary.
1
5. If the valve still does not close, replace the valve.
SERVICE INFORMATION
WARNING
Explosion Hazard and Electrical Shock Hazard.
Can cause explosion, serious injury or death.
Turn off gas supply and disconnect all electrical power
to the valve before servicing.
IMPORTANT
M20911
Only trained, experienced flame safeguard control
technicians should attempt to service or repair flame
safeguard controls and burner assemblies.
Scheduled Inspection and Maintenance
Set up and follow a schedule for periodic inspection and
maintenance, including the burner, all other controls and the
valves. It is recommended that the valve leak test in the
Checkout section be included in this schedule. Refer to the
instructions for the primary safety control(s) for more
inspection and maintenance information.
Screen/Strainer Replacement
1. Make sure that the gas supply is turned off and all
electrical power has been removed.
2. Remove bolts from flange/valve.
3. Remove valve from gas supply line.
4. Remove old screen/strainer.
5. Clean the strainer by using compressed air or replace
the strainer.
6. Install the cleaned strainer or the new strainer.
7. Make sure O-ring sealing surface is clean on flange.
8. Using general purpose lithium grease, grease the
O-ring.
10
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