Samson 3351 - Malfunctions; Troubleshooting

EB 8039 EN 8-1
Malfunctions
8 Malfunctions
Read hazard statements, warnings and caution notes in the 'Safety instructions and mea-
sures' section.
8.1 Troubleshooting
Malfunction Possible reasons Recommended action
Actuator and plug stem
does not move on
demand.
Actuator is blocked. Checkattachment.
Remove the blockage.
WARNING! A blocked actuator or plug stem (e.g.
duetoseizingupafterremaininginthesame
position for a long time) can suddenly start to move
uncontrollably.Injurytohandsorngersispossible
if they are inserted into the actuator or valve.
Before trying to unblock the actuator or plug stem,
disconnect and lock the pneumatic air supply as
well as the control signal. Relieve the compression
before unblocking the actuator. See 'Relieving the
spring compression in the actuator' in the 'Removal'
section.
Diaphragm defective Replace diaphragm (see the 'Servicing' section) or
contact our after-sales service.
Signal pressure too low Checkthesignalpressure.
Checkthesignalpressurelineforleakage.
Actuator and plug stem
does not stroke through
the full range.
Signal pressure too low Checkthesignalpressure.
Checkthesignalpressurelineforleakage.
Incorrect setting of
valve accessories
Checkthesettingsofthevalveaccessories.
Increasedowthrough
closed valve (seat
leakage)
Dirt or other foreign
particles deposited
between the seat and
plug.
Shutoffthesectionofthepipelineandushthe
valve.
Valve trim is worn out.
Replace seat and plug (see the 'Servicing' section)
or contact our after-sales service.
Facing is damaged.