Samson 3256, Mounting And Operating Instructions

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EB 8065 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 de-
mand.
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.
Diaphragm in the actuator
defective
See associated actuator documentation.
Signal pressure too low Check the signal pressure.
Check the signal pressure line for leakage.
Jolting movement of the
actuator and plug stem
Version with adjustable
packing
1)
: packing not
tightened correctly
Tighten the packing correctly (see information
under 'Adjusting the packing' in the 'Testing the
installed valve' section).
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.
Travel stop active See associated actuator documentation.
Incorrect setting of valve ac-
cessories
Check the settings of the valve accessories.
Increased flow through
closed valve (seat leak-
age)
Dirt or other foreign parti -
cles deposited between the
seat and plug.
Shut off the section of the pipeline and flush the
valve.
Valve trim, particularly with
soft seat, is worn.
Replace seat and plug (see the 'Servicing' sec-
tion) or contact our after-sales service.