42
EB 8091-1 EN
Malfunctions
8 Malfunctions
Depending on the operating conditions, check the valve at certain intervals to prevent possi-
ble failure before it can occur. Operators are responsible for drawing up an inspection plan.
SAMSON's After-sales Service department can support you to draw up an inspection plan
for your plant.
8.1 Troubleshooting
Malfunction
Possible reasons
Recommended action
Actuator or plug stem does not
move on demand.
Actuator is blocked.
Check attachment.
Unblock the actuator.
Signal pressure too low
Check the signal pressure.
Check the signal pressure line for
leakage.
Actuator or plug stem does not
move through the whole range.
Signal pressure too low
Check the signal pressure.
Check the signal pressure line for
leakage.
The valve leaks to the atmo-
sphere (fugitive emissions).
The packing is defective.
Replace packing (see sec-
tion 7.2) or contact SAMSON's
After-sales Service department.
Packing tightened incorrectly.
See section 5.3, Adjustable
packing. Contact SAMSON's Af-
ter-sales Service department
when it continues to leak.
Version with bellows seal: the
metal bellows seal is defective.
Contact SAMSON's After-sales
Service department.
Gasket worn out.
Replace body gasket (see sec-
tion 7.1) or contact SAMSON's
After-sales Service department.
Increased flow through closed
valve (seat leakage)
Dirt or other foreign particles de-
posited between the seat and
plug.
Shut off the section of the pipe-
line and flush the valve.
Valve trim, particularly with soft
seat, is worn.
Replace seat and plug (see sec-
tion 7.3 or contact SAMSON's
After-sales Service department).
Tip
Summary of Contents for 3510
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