EB 3009 EN
11
Maintenance
Table 1:
Troubleshooting
Malfunction
Possible reasons
Recommended action
The valve does not fully open.
The differential pressure exceeds
the set point.
Insufficient upstream pressure
pulses on the actuator dia-
phragm
Clean the control line and the
screw joint with restriction.
Two diaphragms defective
(check the diaphragm rupture
indicator).
Replace operating diaphragms.
Seat and plug worn down by
deposits or foreign particles.
Replace damaged parts or
contact SAMSON's After-sales
Service department.
Strainer blocked
Clean strainer.
Valve too small
Recalculate C
V
/K
VS
coefficient
and contact SAMSON.
The valve does not close. The
differential pressure drops be-
low the set point.
Seat and plug damaged impair-
ing tight shut-off.
Remove valve from the pipeline
and clean parts. Contact
SAMSON's After-sales Service
department if the regulator is
defective.
Valve too large
Recalculate C
V
/K
VS
coefficient
and contact SAMSON.
Control line downstream of
valve blocked.
Clean the control line and the
screw joint with restriction.
Jerky control response.
Increased friction, e.g. due to
foreign particles between seat
and plug.
Remove valve from the pipeline
and clean parts.
Control loop hunts.
Valve too large
Recalculate C
V
/K
VS
coefficient
and contact SAMSON.
If faults cannot be remedied following the recommended action in the table, contact
SAMSON (see section 7).
