Series 751 FireLock® Alarm Check Valve
20
TROUBLESHOOTING – SERIES 751 ALARM CHECK VALVE
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Problem
Possible Cause
Solution
The system water pressure gauge is fluctuating
with the supply pressure
The check valve in the bypass line is installed
backward.
Check the orientation of the bypass check valve.
The arrow must point from the supply side to the
system side.
Debris is present in the bypass check valve.
Remove the threaded cap from the check valve to
remove any debris. Make sure the clapper has
freedom of movement.
Water is leaking from the intermediate chamber
Water is getting past the seal.
Check the clapper seal and seat for physical
damage. Make sure no debris is present on the
clapper seal and seat.
Make sure there is no vacuum in the alarm line. If a
vacuum is present in the alarm line, install the
Series 752V Retard Vent Kit or create some means
of an air break in the alarm line.
The water motor gong is not ringing, or the ringing
is weak
No water is going into the intermediate chamber.
Make sure the holes in the seat ring are not
plugged.
Water from the alarm line could be leaking out of
the alarm line drain of another valve.
Make sure there are check valves isolating the
alarm line of each valve in the system.
The wrong restrictor size is installed in the alarm
line drain.
Confirm that the proper restrictor size is installed in
the alarm drain. If the proper restrictor size is not
installed, refer to the trim drawing to replace the
restrictor with the correct size.