GEM 550 Installation, Operating And Maintenance Instructions

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

GEM 550 Specifications

General

Brand	GEM
Model	550
Category	Control Unit
Language	English