Troubleshooting / Fault Clearance - Gemü 695 Original Einbau- Und Montageanleitung

18

Troubleshooting / Fault clearance

Fault
Control medium escacpes from
vent hole* in the actuator cover
(for control function NC) or
from connector 2* (for control
function NO)
Control medium escapes from
leak detection hole* (only for
control function NC and control
function DA)
Working medium escapes from
leak detection hole*
Control medium escapes at the
actuator membrane*
Valve doesn't open or doesn't
open fully
Valve leaks downstream
(doesn't close or doesn't close
fully)
Valve leaks between actuator
and valve body
Valve body connection to
piping leaks
Valve body leaks
* see chapter 19 "Sectional drawing and spare parts"
695
Possible cause
Actuator membrane faulty
Spindle seal leaking
Valve diaphragm faulty
Connecting bolts between actuator
cover and base are loose
Control pressure too low
(for control function NC)
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
Actuator spring faulty
(for control function NC)
Valve diaphragm incorrectly mounted
Bolting between valve body and
actuator loose
Valve diaphragm faulty
Actuator / valve body damaged
Incorrect installation
Threaded connections / bolting loose
Sealing material faulty
Valve body faulty or corroded
34 / 40
Fault clearance
Replace actuator
Replace actuator and check control
medium for impurities
Check valve diaphragm for damage,
replace diaphragm if necessary
Retighten bolts professionally diagonally
Operate valve with control pressure
specified in data sheet
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
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
Replace actuator / valve body
Check installation of valve body in piping
Tighten threaded connections / bolting
Replace sealing material
Check valve body for damage, replace
valve body if necessary