Troubleshooting / Fault Clearance - Gemü 554 Montageanleitung

19 Troubleshooting / Fault clearance

Fault
Control medium escapes
from vent hole* (for
control function 1 (NC))
or from connector 2* (for
control function 2 (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
actuator and valve body
Valve body connection to
piping leaks
Valve body leaks
* see chapter 20 "Sectional drawing and spare parts"
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Possible cause
Actuator piston leaking
Spindle seal leaking
Gland packing faulty
Control pressure too low
Control medium not connected
Actuator piston or spindle sealing
leaky
Actuator spring faulty (for control
function 2, normally open (NO))
Operating pressure too high
Foreign matter between seat
seal* and seat
Valve body leaky or damaged
Seat seal* faulty
Actuator spring faulty (for control
function 1, normally closed (NC))
Actuator loose
Gasket* faulty
Valve body / actuator damaged
Incorrect installation
Threaded connections / bolting
loose
Sealing material faulty
Valve body leaks or is corroded
Fault clearance
Replace actuator and check control medium for
impurities
Replace actuator and check control medium for
impurities
Replace actuator
Set control pressure in accordance with data sheet.
Check pilot valve and replace if necessary
Connect control medium
Replace actuator and check control medium for
impurities
Replace actuator
Operate valve with operating pressure specifi ed in
data sheet
Remove actuator, remove foreign matter, check
seat seal for damage and replace if necessary
(replace actuator for actuator size B)
Check valve body and replace if necessary
Check seat seal for damage and replace if
necessary (replace actuator for actuator size B)
Replace actuator
Tighten the actuator using the union nut*
Check gasket and the respective sealing surfaces
for damage and replace parts if necessary
Replace valve body / actuator
Check installation of valve body in piping
Tighten threaded connections / bolting
Replace sealing material
Check valve body for damage, replace valve body
if necessary
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