Samson 3321CT, Mounting And Operating Instructions

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EB 8115 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 fingers 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. Before unblocking the
actuator, release any stored energy in the actuator
(e.g. spring compression). See associated actuator
documentation.
Signal pressure too low Check the signal pressure.
Check the signal pressure line for leakage.
Actuator and plug stem
does not stroke through
the entire range.
Signal pressure too low Check the signal pressure.
Check the signal pressure line for leakage.
Increased flow through
closed valve (seat
leakage)
Dirt or other foreign
particles deposited
between the seat and
plug.
Shut off the section of the pipeline and flush the
valve.
Valve trim is worn out. Replace seat and plug (see the 'Servicing' section)
or contact our after-sales service.
The valve leaks to the
atmosphere (fugitive
emissions).
Defective packing Replace packing (see the 'Servicing' section) or
contact our after-sales service.
Flanged joint loose or
gasket worn out
Check the flanged joint.
Replace gasket at the flanged joint (see the
'Servicing' section) or contact our after-sales
service.