INSTALLATION, OPERATION, &
MAINTENANCE MANUAL
TITLE:
F84L Series Liquid Relief Valve
Rev. J
Page 13 of 18
6.0
TROUBLESHOOTING GUIDE (continued):
Symptom
Possible Cause
Remedy
The valve does not
open.
Spindle is stuck closed.
Disassemble the valve and examine the
sliding surfaces. If damaged, replace.
If contaminated, clean.
Nozzle is stuck to seat.
Disassemble and check seat for
permanent impression(s). Harder seat
material may be needed.
The set pressure has not been
reached.
Increase inlet pressure. Confirm
pressure gage is calibrated.
Isolation valve is closed.
Open isolation (block) valve.
The valve chatters or
rapid-cycles.
The valve is oversized for the
application.
Install smaller valve.
The inlet is choked.
Increase size of inlet piping to be equal
to or greater than the valve orifice.
Check for piping restrictions or partially
closed valves.
Too much built-up backpressure
due to excessive flow, or outlet
piping undersized or too long.
Reduce backpressure by reducing flow
rate or reworking outlet piping (increase
size; shorten; reduce number of turns).
It is recommended that outlet piping
size be equal to or greater than the
valve outlet size.