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Installation, Operation and Maintenance - Series LF920GD
Setting the Pressure Controls
STEP 1
Pre-set pilots as noted:
Pressure Sustaining –Turn Sustaining Control adjustment screw OUT, counterclockwise, backing pressure off the spring, to allow it to
stay open while adjusting the other controls.
Pressure Reducing – Adjust OUT, counterclockwise, backing pressure off the spring, preventing possible over-pressuring of the system.
Opening and Closing Speed – Turn the adjustment screws on the Closing Speed and Opening Speed Controls, if the main valve is so
equipped, OUT, counterclockwise, 1
STEP 2
To ensure proper operation, any trapped air will need to be bled off
the valve cover during startup. If your ACV includes a bleed valve,
as shown to the right, use a flat head screwdriver to slowly open
the valve (See Figure 1).
If your valve does not include a bleed valve, bleed air by loosening
a fitting on the valve or a plug, at the highest point of the valve as-
sembly.
STEP 3
Pressure the line, by opening the upstream isolation valve slowly
Air is vented through the air bleed valve or loosened fitting. Tighten
the fitting when liquid begins to vent (See Figure 1).
Repeat the process until no air is trapped in the system.
STEP 4
Slowly open downstream isolation valve to establish flow through
the system.
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 up-
stream isolation valve until the inlet pressure drops to the desired
setting.
STEP 7
Adjust the Sustaining Control screw IN, clockwise, until the inlet
pressure begins to increase, or OUT, counterclockwise to de-
crease, stopping at the desired pressure (See Figure 2).
ES-A-ACV-LF920GD 2115
to 2
turns from full closed position.
1/2
1/2
Counterclockwise to OPEN
bleed valve
Position Indicator
Clockwise to increase inlet
pressure
PV20C — Pressure Sustaining Control
15
Figure 1
Counterclockwise to decrease
inlet pressure
Figure 2
© 2021 Watts
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