Troubleshooting / Fault Clearance - GEM 674 Installation, Operating And Maintenance Instructions

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Troubleshooting / Fault clearance

Fault
Medium escapes from leak
detection hole (see sectional
drawings chapter 20)
Valve doesn't open or doesn't
open fully
Valve leaks downstream
(doesn't close or doesn't close
fully)
Valve leaks between
bonnet and valve body
Valve body connection to
piping leaks
Valve body leaks
Handwheel cannot be turned
Possible cause
Valve diaphragm faulty
Bonnet faulty
Valve diaphragm incorrectly
mounted
Operating pressure too high
Foreign matter between valve
diaphragm and valve body weir
Valve body weir leaking or damaged
Valve diaphragm faulty
Valve diaphragm incorrectly
mounted
Bolting between valve body and
bonnet loose
Valve diaphragm faulty
Valve body damaged
Incorrect installation
Bolting loose
Sealing material faulty
Valve body faulty or corroded
Bonnet faulty
Handwheel clamp locked
(only GEMÜ 675)
31 / 36
Fault clearance
Check valve diaphragm for damage,
replace diaphragm if necessary
Replace bonnet
Remove bonnet, check diaphragm
mounting, replace if necessary
Operate valve with operating pressure
specifi ed in data sheet
Remove bonnet, remove foreign matter,
check valve diaphragm and valve body
weir for damage and replace if necessary
Check valve body weir for damage, if
necessary replace valve body
Check valve diaphragm for damage,
replace diaphragm if necessary
Remove bonnet, check diaphragm
mounting, replace if necessary
Retighten bolting between valve body and
bonnet
Check valve diaphragm for damage,
replace diaphragm if necessary
Replace valve body
Check installation of valve body in piping
Tighten bolting
Replace sealing material
Check valve body for damage, replace
valve body if necessary
Replace bonnet
Unlock handwheel clamp
(only GEMÜ 675)
674, 675_us