7 faults; causes and remedies – Flowserve BP User Manual
Page 37

BP USER INSTRUCTIONS ENGLISH 85392725 10-09 (E)
Page 37 of 44
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7 FAULTS; CAUSES AND REMEDIES
FAULT SYMPTOM
P u m p o ve r h e a ts a n d s e i z e s
B e a r i n g s h a v e s h o r t l i f e o r a r e d a m a g e d
P u m p vi b r a t e s o r i s n o i s y
M e c h a n i c a l s e a l h a s s h o r t l i f e
M e c h a n i c a l s e a l l e a k s e x c e s s i ve l y
P u m p r e q u i r e s e x c e s s i ve p ow e r
P u m p l o s e s p r i m e a ft e r s ta r t i n g
I n s u f f i c i e n t p r e s s u r e d e v e l o p e d
I n s u f f i c i e n t c a pa c i t y d e l i v e r e d
P u m p d o e s n o t d e l i ve r l i q u i d
PROBABLE CAUSES
PROBABLE REMEDIES
A. System troubles
● ●
Pump not primed.
● ● ● ●
Pump or suction pipe not completely filled
with liquid.
Check complete filling. Vent and/or prime.
● ● ● ●
Suction lift too high or level too low.
● ● ● ●
Insufficient margin between suction pressure
and vapor pressure.
Check NPSHa>NPSHr, proper submergence,
looses at strainers/fittings.
● ● ●
Excessive amount of air or gas in liquid.
Check and purge pipes and system.
● ● ●
Air or vapor pocket in suction line.
Check suction line design for vapour pockets.
● ●
Air leaks into suction line.
Check suction pipe is airtight.
● ●
Air leaks into pump through mechanical seal,
sleeve joints, casing joint or pipe plugs.
Check and replace faulty parts.
CONSULT FLOWSERVE.
● ● ● ●
Discharge or suction valve is closed.
Open the valve.
● ●
Suction valve too small.
Investigate replacing the Suction valve.
● ●
Suction valve, strainer or suction piping
partially clogged.
Clean Suction valve, strainer, suction piping.
● ● ● ●
Inlet of suction pipe insufficiently submerged.
Check out system design.
● ● ●
Speed too low.
CONSULT FLOWSERVE.
●
Speed too high.
CONSULT FLOWSERVE.
● ● ●
Total head of system higher than differential
head of pump.
●
Total head of system lower than pump design
head.
Check system losses. Remedy or CONSULT
FLOWSERVE.
●
Specific gravity of liquid different from design.
● ● ●
Viscosity of liquid different from that for which
designed.
Check and CONSULT FLOWSERVE.
● ●
Operation at very low capacity.
Measure value and check minimum permitted.
Remedy or CONSULT FLOWSERVE.
● ● ●
Operation at high capacity.
Measure value and check maximum permitted.
Remedy or CONSULT FLOWSERVE.