Troubleshooting / Fault Clearance - Gemü DN 4 - 25 Montageanleitung

19 Troubleshooting / Fault clearance

Fault
Control medium escapes from
connector 4* (control function
NC) or from connector 2*
(control function NO)
Control medium escapes from
leak detection hole*
Working medium escapes from
leak detection hole*
Valve doesn't open or doesn't
open fully
Valve leaks downstream
(doesn't close or doesn't close
fully)
Valve leaks between
diaphragm and valve body
Valve body connection to
piping leaks
Valve body leaks
* see chapter 20 "Sectional drawing and spare parts"
660
Possible cause
Actuator piston leaking
Spindle seal leaking
Valve diaphragm faulty
Control pressure too low
(for control function NC)
Actuator faulty
Stroke limiter incorrectly set
Pilot valve faulty
Control medium not connected
Valve diaphragm incorrectly mounted
Actuator spring faulty
(for control function NO)
Operating pressure too high
Control pressure too low (for control
function NO and control function DA)
Foreign matter between valve diaphragm
and valve body weir
Valve body weir leaking or damaged
Valve diaphragm faulty
Seal adjuster is incorrectly set
Actuator spring faulty
(for control function NC)
Valve diaphragm incorrectly mounted
Bolting between valve body and actuator
loose
Valve diaphragm faulty
Distance sleeves incorrectly mounted
Valve body damaged
Incorrect installation
Threaded connections loose
Sealing material faulty
Valve body faulty or corroded
42 / 48
Fault clearance
Replace actuator
Replace actuator and check control
medium for impurities
Check valve diaphragm for damage,
replace diaphragm if necessary
Operate valve with control pressure
specified in data sheet
Replace actuator
Readjust the stroke limiter
Check and replace pilot valve
Connect control medium
Remove actuator, check diaphragm
mounting, replace if necessary
Replace actuator
Operate valve with operating pressure
specified in data sheet
Operate valve with control pressure
specified in data sheet
Remove actuator, 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
Readjust the seal adjuster
Replace actuator
Remove actuator, check diaphragm
mounting, replace if necessary
Retighten bolting between valve body
and actuator
Check valve diaphragm for damage,
replace diaphragm if necessary
Correctly mount distance sleeves
Replace valve body
Check installation of valve body in piping
Tighten threaded connections
Replace sealing material
Check valve body for damage, replace
valve body if necessary