Advertisement
V4730B/V8730B, V4750B/V8750B CLASS A DOUBLE BLOCK AND PRESSURE REGULATING SAFETY SHUTOFF VALVES
Second Valve, Slow Opening
(V4750B/V8750B)
The flow rate, opening speed, and the step pressure can be
adjusted.
IMPORTANT
To ensure a satisfactory setting of the valve, the
pressure drop over the valve should be at least 10%
of the supply pressure or 1 in. w.c. (2.5 mBar),
whichever is greater.
Flow rate is adjustable from 0% to 100% of full rated flow. To
adjust the flow rate (Fig. 12 and 13):
1. Remove the cap from the top of the coil by loosening
both screws.
2. Place a wrench on the adjustment nut.
3. Turn the wrench counterclockwise
clockwise
to decrease the flow rate.
Fig. 12. Removing the cap.
M17980A
Fig. 13. Turning the flow rate adjustment nut.
NOTE: Step pressure is adjustable from 0 to 90% of setpoint
pressure.
65-0275—2
to increase or
M17979A
8
To adjust the step pressure (FIg. 12 and 14):
1. Remove the cap from the top of the coil by loosening
both screws.
2. Place a screwdriver in the slot of the adjustment screw,
located in the center of the top of the valve.
3. Turn the screwdriver counterclockwise
increase or clockwise
pressure.
4. Replace the cap on top of the coil.
Opening Speed Adjustment
(V4750B/V8750B)
Opening speed can be adjusted between one second
minimum and 90 seconds maximum. See Fig. 15 and 16.
Fig. 14. Turning the step pressure adjustment screw.
SLOWER
OPENING
Fig. 15. Opening speed adjustment screw.
to
to decrease step
M17981A
FASTER
OPENING
M17982B
Advertisement
