Gemu 650 - Troubleshooting; Fault Clearance

19 Troubleshooting / Fault clearance
Error Possible cause Troubleshooting
Control medium escapes from
vent hole*/vent* in the actuator
cover for control function NC
or connector 2 for control
function NO (see chapter 10.2
"Control functions").
Piston faulty Replace the actuator
Control medium escapes from
leak detection hole*
Spindle seal leaking
Replace the actuator and check control
medium for impurities
Working medium escapes
from leak detection hole*
Shut off diaphragm faulty
Check shut off diaphragm for potential
damage, replace diaphragm if necessary
Valve doesn't open or doesn't
open fully
Control pressure too low
(for control function NC)
Operate valve with control pressure
specified in data sheet
Pilot valve faulty Check and replace pilot valve
Actuator defective Replace the actuator
Control medium not connected Connect the control medium
Shut off diaphragm incorrectly mounted
Remove actuator, check diaphragm
mounting, replace if necessary
Actuator spring faulty
(for control function NO)
Replace the actuator
Valve leaks downstream
(doesn't close or doesn't close
fully)
Operating pressure too high
Operate valve with operating pressure
specified in datasheet
Control pressure too low (for control
function NO and control function DA)
Operate valve with control pressure
specified in data sheet
Foreign matter between shut off
diaphragm and valve body weir
Remove actuator, remove foreign matter,
check diaphragm and valve body weir
for potential damage and replace if
necessary
Valve body weir leaking or damaged
Check valve body weir for damage, if
necessary replace valve body
Shut off diaphragm faulty
Check shut off diaphragm for potential
damage, replace diaphragm if necessary
Actuator spring faulty
(for control function NC)
Replace the actuator
Valve leaks between actuator
and valve body
Shut off diaphragm incorrectly mounted
Remove actuator, check diaphragm
mounting, replace if necessary
Bolting between valve body and
actuator loose
Retighten bolting between valve body
and actuator
Shut off diaphragm faulty
Check shut off diaphragm for potential
damage, replace diaphragm if necessary
Actuator/valve body damaged Replace the actuator/valve body
Valve body connection to
piping leaks
Incorrect installation Check installation of valve body in piping
Unions/threaded connections loose Tighten unions/threaded connections
Sealing material faulty Replace sealing material
Valve body leaks Valve body faulty or corroded
Check valve body for potential damage,
replace valve body if necessary
* see chapter 19 "Sectional drawings and spare parts"
45 / 52
650