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V4730B/V8730B, V4750B/V8750B CLASS A DOUBLE BLOCK AND PRESSURE REGULATING SAFETY SHUTOFF VALVES
OPENING SPEED REGULATION
STEP
PRESSURE
Fig. 16. Characterized opening.
Pressure Regulator
Pressure regulation is adjustable from 1.2 in. to 15 in. wc.
1. Remove cap from regulator.
2. Turn adjusting screw clockwise
output pressure or counterclockwise
the pressure.
3. Replace the regulator cover cap.
Final Checkout of the Installation
Set the system in operation after any adjustment is completed
and observe several complete cycles to ensure that all burner
components function correctly.
OPERATION
The V4730B/V8730B, V4750B/V8750B are normally closed
valves. The valves open when energized and close when the
power is removed.
WARNING
Explosion Hazard and Electrical Shock Hazard.
Can cause explosion, serious injury or death.
1. Do not put the system into service until you have
satisfactorily completed the Valve Leak Test, all
applicable tests described in the Checkout section
of the instructions for the flame safeguard control
and any other tests required by the burner
manufacturer.
2. All test must be performed by a trained, experienced
flame safeguard technician.
3. Close all manual fuel shutoff valves immediately if
trouble occurs.
After the installation is complete, cycle the valve several times
with the manual fuel shutoff cock closed. Make sure the valve
functions properly. Also, perform the Valve Leak Test before
putting the valve into service.
100% FLOW
FLOW REGULATION
0% FLOW
TIME
M17983C
to increase the
to decrease
9
Valve Leak Test (Fig. 17)
This is a test for checking the closure tightness of the gas
shutoff valve. It should be performed only by trained,
experienced flame safeguard technicians during the initial
startup of the burner system or whenever the valve is
replaced. It is recommended that this test also be included in
the scheduled inspection and maintenance procedures. For a
periodic inspection test, follow steps 1, 3, 4, 5, 8, 9, 10, 12, 13,
16 and 17.
WARNING
Electrical Shock Hazard.
Can cause serious injury, death or equipment
damage.
Remove the power from the system before beginning
the valve leak test. More than one disconnect may be
involved.
1. De-energize the control system to make sure no power
goes to the valves.
2. Close the upstream manual gas cock (A).
3. Make sure the manual test petcock (F) is closed in the
leak test tap assembly
4. To test the first SSOV, remove the 1/8 in. (3 mm) NPT
plug from pressure tap point P.
5. Install the leak test tap into pressure tap point P on the
valve body.
6. Open the upstream manual gas cock (A) to repressurize
the first SSOV.
7. Immerse the 1/4 in. (6 mm) tube vertically 1/2 in.
(13 mm) into a jar of water.
8. Slowly open the manual test petcock (F).
9. When the rate of bubbles coming through the water
stabilizes, count the number of bubbles appearing
during a ten-second period. Each bubble appearing
during a 10-second period represents a flow rate of
0.001 cfh (28 cch). See Table 3.
Table 3. Maximum Bubbles per Pipe Size.
Pipe Size (in.
Maximum Seat
NPT)
Leakage (UL)
1/2-3/4
235 cch
1
275 cch
1-1/4
340 cch
10. Close the upstream manual gas cock (A).
11. Remove the leak test tap from the valve body.
12. Using a small amount of pipe sealant on the 1/8 in.
(3 mm) NPT plug, reinstall the plug in pressure tap
point P.
13. To test the second SSOV, remove the 1/8 in. (3mm)
NPT plug from the flange pressure tap point 4.
14. Install the leak test tap into pressure tap point 4.
15. Close the downstream manual gas cock E.
16. Immerse the 1/4 in. (6 mm) tube vertically 1/2 in.
(13 mm) into a jar of water.
17. Slowly open the manual test petcock (F).
18. When the rate of bubbles coming through the water
stabilizes, count the number of bubbles appearing
during a ten-second period. Each bubble appearing
represents a flow rate of 0.001 cfh (28 cch). See
Table 3.
Maximum Number
of Bubbles/10
seconds
6
7
8
65-0275—2
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