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Troubleshooting Guide
Issue
Possible Cause
Main Valve will not
Closed isolation valves in pilot system.
open
Insufficient supply pressure.
Main valve stem assembly corroded/
damaged.
Blockage in pilot system.
Missing fixed orifice assembly.
Improperly configured opening speed
control (if equipped).
Main Valve will not
Closed isolation valves in pilot system
close
Diaphragm is damaged
Main valve stem assembly corroded/
damaged.
Blockage in main valve.
Worn/damaged valve seat.
IOM-A-ACV-910_610 2115
Corrective Action
Check isolation valves, ensure
open.
Check upstream pressure.
Inspect stem assembly, clean/
replace if necessary.
Inspect & clean any installed
pilot system strainers, check
orifice/speed controls for
blockages.
Verify installation of orifice;
replace if required/missing.
Adjust opening speed control
to verify functionality, adjust as
required.
Check isolation valves, ensure
open.
Conduct diaphragm seal test,
repair and replace if necessary.
Inspect stem assembly, clean/
replace if necessary.
Perform freedom of movement
test; if valve does not close,
disassemble and remove
blockage.
Perform seat sealing check;
disassemble and inspect/repair
seat if required.
EDP# 1917028
Notes
Depending on water
source, supply pressure
may not be controlled by
valve operator.
Pilot valve inlet isolation
valve can be used as a
makeshift orifice assembly
by partially opening from
full closed position.
Standard setting for
opening speed control is
11/2 - 21/2 turns open from
full closed position. Can
be adjusted in field.
© 2021 Watts
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