Check the adjusted set point on the pressure
gauge installed upstream of the regulator
(Fig. 3).
3.3
Decommissioning
We recommend to close the upstream shut-off
valve before closing the shut-off valve in-
stalled downstream of the regulator.
4
Maintenance
and
trouble-
shooting
The pressure regulator is maintenance free.
Nevertheless, it is subject to natural wear,
particularly at the seat, plug and operating
diaphragm.
Depending on the operating conditions, the
regulator needs to be checked at regular in-
tervals to detect and remove possible mal-
functions.
CAUTION!
For installation and maintenance work on the
regulator, make sure the relevant plant sec-
tion has been depressurized and, depending
on the process medium, drained as well. We
recommend to remove the regulator from the
pipeline.
If necessary, allow the regulator to cool down
to reach ambient temperature before starting
any work on it.
Disconnect or shut off the control line to avoid
any hazards that could be caused by moving
regulator parts.
As valves are not free of cavities, remember
that residual process medium might still be
contained in the valve.
4.1
Pressure fluctuations
NOTICE
Pressure fluctuations (oscillation) may dam-
age the regulator and plant. As a result, pre-
vent them from occurring or remove their
cause immediately.
To stop oscillation from occurring, the follow-
ing actions may be helpful:
4
Check the pressure tapping point at the
control line (refer to section 2.5); if neces-
sary, move the tapping point.
4
Screw a SAMSON restriction into the
sleeve for the tapped connection (9): or-
der no. 1991-7114 for 1200 and
640 cm², order no. 1991-7113 for 320
and 160 cm².
4
Check the regulator's sizing data. If nec-
essary, change the K
VS
coefficient, seat di-
ameter or diaphragm area.
Contact SAMSON (refer to section 6) if the
problems persist.
8
EB 2528 EN
Maintenance and troubleshooting
