Step 10
Open Opening Speed Flow Control Adjustment:
The Opening
Speed Flow Control allows free flow into the cover and restricted
flow out of the cover of the main valve.
If valve opening is too slow, turn the adjustment screw OUT,
counterclockwise (See Figure 3B), increasing the rate of opening.
If valve opening is too quick, turn the adjustment screw IN, clock-
wise (See Figure 3A), decreasing the rate of opening.
Step 11
Closing Speed Needle Valve Adjustment: The closing speed
needle valve regulates fluid pressure into the main valve cover
chamber, controlling the valve closing speed. If valve closing is too
slow, turn the adjustment screw OUT, counterclockwise, increas-
ing the rate of closing.
STEP 12
Open upstream isolation valve to return to normal operation.
STEP 5
Setting the Sustaining Control requires lowering the upstream
pressure to the desired minimum sustained pressure.
STEP 6
Leave the downstream isolation valve fully open and close the
upstream isolation valve until the inlet pressure drops to the
desired setting.
STEP 7
Adjust the Sustaining Control screw IN, clockwise (See Figure
2A), until the inlet pressure begins to increase, or OUT, counter-
clockwise (See Figure 2B) to decrease, stopping at the desired
pressure.
Step 8
Allow pressure to stabilize.
Step 9
Fine-tune the sustaining setting as required as detailed in STEP 7.
Setting the Sustaining Control Pilot
4 IOM-A-ACV-979-20_679-20 2115
EDP# 1917116
© 2021 Watts
IOM-A-ACV-979-20_679-20 2115
EDP# 1917116
© 2021 Watts 5
Counterclockwise to INCREASE
the rate of opening
Clockwise to DECREASE
rate of opening
3A
3B
Figure 3
Flow Control
Figure 2
PV20C — Pressure Sustaining Control
Clockwise to increase inlet
pressure
2A
2B
Counterclockwise to decrease
inlet pressure
