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V4730B/V8730B, V4750B/V8750B CLASS A DOUBLE BLOCK AND PRESSURE REGULATING SAFETY SHUTOFF VALVES
Wiring
1. Use 14, 16 or 18 AWG copper conductor, 600 volt
insulation, moisture-resistant wire for line voltage
connections. Recommended wire types are TTW60C,
THW75C or THHN90C.
2. Follow the instructions below for wiring the gas valve.
See Fig. 9 and 10 for reference.
a. T1 (yellow) will be L2 (120 Vac or 24 Vac).
b. T2 (black) will be L1 (120 vac or 24 Vac) to Valve 1.
c. T3 (blue) will be L1 (120 Vac or 24 Vac) to Valve 2.
d. Ground (green) will be earth ground.
.
(GREEN)
V1
2
(BLACK)
3
V2
(BLUE)
1 FOR CONNECTION TO 1/2 INCH FLEXIBLE ELECTRICAL
CONDUIT ONLY. MAXIMUM TORQUE 65 INCH-POUNDS.
Fig. 9. Four-pin electrical plug connector.
BLACK
2
V1
Fig. 10. Electrical connection diagram.
ADJUSTMENTS AND FINAL
CHECKOUT
The following procedures are related to the adjustments on
the main gas valve. For adjustment of the other devices (i.e.,
pressure switches), refer to the instructions supplied with the
applicable device.
WARNING
Fire or Explosion Hazard.
Can cause serious injury, death or property
damage.
Only fully qualified, experienced flame safeguard
technicians should make adjustments on the valve.
1
L2
(YELLOW)
1
M20583
BLUE
3
YELLOW
1
V2
M20584
Pressure Tap Points (Fig. 11)
The V4730B/V8730B, V4750B/V8750B, have a number of
connection points (1/8 in. [3 mm] NPT plugs) for measuring
pressure and/or mounting a pressure switch. The pressure tap
points are:
1 Inlet pressure at first SSOV flange tap.
2 Inlet pressure at first SSOV.
P Outlet pressure at first SSOV.
3 Inlet pressure at second SSOV.
4 Outlet pressure at second SSOV flange tap.
The following pressures can be measured:
1. Inlet pressure—tap on inlet flange (1).
2. Pressure after inlet screen (2).
3. Unregulated intermediate pressure—pressure between
the two shutoff seats (P).
4. Regulated intermediate pressure—pressure between
the two shutoff valves (3).
5. Outlet pressure—tap from flange (4).
The corresponding numbers (2,P, 3) can be found on the side
of the valve.
NOTE: To mount the C6097 Pressure Switch, refer to
instructions in form 65-0237, furnished with the
switch. The pressure switch can be mounted to 2, P
or 3 on either side of the valve body.
1
OPTIONAL
C6097
PRESSURE
SWITCH
Fig. 11. Pressure tap points.
Second Valve, Fast Opening
(V4730B/V8730B)
Flow rate is adjustable from 0% to 100% of full rated flow. To
adjust the flow rate:
1. Remove the flat, round, blue plastic cap from the cover.
2. Using a 3 mm (7/64 in.) hex wrench, turn the adjustment
screw counterclockwise
clockwise
3. Snap the flat, round, blue plastic cap back on the cover.
7
2
P
3
2
P
3
M17985C
to increase or
to decrease the flow rate.
4
65-0275—2
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