40 EB 8026 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-
tion7.2) or contact SAMSON's
After-sales Service department.
Version with adjustable
packing
1)
: packing not tightened
correctly.
See section5.3, Adjustable
packing. Contact SAMSON's
After-sales Service department
when it continues to leak.
Version with bellows seal: the
bellows seal is defective.
Contact SAMSON's After-sales
Service department.
Flange joint loose or gasket
worn out.
Check the ange joint.
Replace gasket at the anged
joint (see section7.1 or contact
SAMSON's After-sales Service
department).
Tip