4 trouble shooting – Flowserve V901 VariCool Desuperheater User Manual
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4 Trouble shooting 
 
Defect
No.
Possible cause
Remedy
 
Spindle does not move 
1.1
 
 
 
 
 
 
 
1.2
 
 
 
1.3
 
 
1.4
 
 
 
1.5
 
 
 
 
 
1.6
 
• 
no aux. energy supply ( 
pneumatic air or electrical power 
) to actuator and accessories ( 
solenoid valve, filter reducing 
station, positioner, limit switch 
and special accessories ) 
•
the fitted accessories do not 
work 
 
 
•
the pneumatic actuator is 
defective 
•
the electrical actuator is 
defective 
 
 
•
excessive tightening of the 
stuffing box packing 
 
 
 
 
•
Valve trim worn, stuck
 
• 
pneumatic actuators: check supply 
line for leaks; check pressure ( 
usually 6 bar ) 
•
electrical actuators: check power 
supply (connections, circuit breakers, 
voltage) 
•
see maintenance and operating 
instructions of accessories 
manufacturer 
•
contact customer service 
departement or contract partner 
•
see maintenance and operating 
instructions of actuator manufacturer 
•
loosen stuffing box packing nuts until 
valve operates properly 
Caution: make sure there are no leaks !
•
contact customer service 
departement or contract partner 
 
Jolting spindle movement 
 
2.1 
 
 
2.2 
 
 
2.3
•
dirty spindle
 
• 
damaged spindle
 
 
•
actuator not powerful enough
 
• 
clean spindle with suitable cleaning 
agent 
•
contact customer service department 
or a contract partner 
•
compare actuator specs on the 
rating plate with operation 
specifications of the facility - if 
incompatible, contact customer 
service department or 
contract
partner
 
Spindle travel less than full 
stroke 
( 0 to 100% stroke ) 
 
3.1 
 
 
3.2
 
 
 
3.3
 
 
3.4
 
 
3.5
 
• 
air supply pressure too low
 
 
•
pneumatic actuators: bad hand 
wheel position (hand wheel 
emergency operation) 
•
electrical actuators: limit switch 
misadjusted 
•
badly adjusted or defective 
positioner 
•
foreign particles in valve seat, 
damaged trim 
 
• 
provide air at the pressure stated on 
the rating plate 
•
take hand wheel to limit position
 
 
 
•
readjust limit switch to actuator manu 
facturer`s specifications 
•
readjust positioner to positioner 
manu facturer`s specifications 
•
contact customer services 
department or 
contract partner
