Richter RSS/F Series Bellows-Sealed Control Valves - Manual (Page 13)

Series RSS/F
Page 13
9260-060-en Revision 03
TM 7168 Edition 06/2008
8 Malfunctions
Flange connection valve/pipe is leaking
Retighten the flange screws to a tightening torque
according to Section 1.3. If this does not remedy
the leak, the recommended torques may be ex-
ceeded by 10%.
If this also fails to stop the leak, dismantle and
inspect the valve.
Flange connection main body/cover is leaking
Retighten the cover screws to a tightening torque
according to Section 1.3. If this does not remedy
the leak, the recommended torques may be ex-
ceeded by 10%.
If this also fails to stop the leak, dismantle and
inspect the valve.
Packing is leaking
First of all, the packing gland follower can be
tightened.
Then dismount the valve as quickly as possible and
repair.
Disadvantages:
The medium can destroy the metallic internals
relatively quickly.
Corrosion on the stem may result in sluggish-
ness and therefore impair the control behaviour.
Replace bellows.
Replace plug and/or seat.
Replace packing rings.
Monitoring connection reports a rise in pressure or
a leak
Replace bellows.
Replace plug and/or seat.
Replace packing rings.
Valve does not switch
Is the actuator supplied with power?
Is any directional control valve correctly connec-
ted?
Is there any foreign matter in the control valve?
Is the stuffing box tightened too much?
Valve does not close tight
Check distance of the travel stop.
Are there any solids between seat and plug?
Are the sealing surfaces of the seat or plug dama-
ged?
Is the actuator too small?
Is the air pressure high enough?
Is the positioner set correctly?
Valve does not open completely
Is the air pressure high enough?
Is the positioner set correctly?
Does the actuator permit enough travel?
Does the valve permit enough travel?
The flow rate is too high or too low.
The performance curve is not correct.
The valve cavitates.
Do the rated data according to the data sheet or
works certificate match the data of the plant?
Are the correct seat and plug installed? See mar-
kings on the seat and plug and compare them with
the name plate and the data sheet.