Faults; Causes And Remedies - Flowserve CPX User Instructions

7 FAULTS; CAUSES AND REMEDIES

FAULT SYMPTOM
P u m p o v e r h e a t s 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
⇓ ⇓ ⇓ ⇓
⇓ ⇓ ⇓ ⇓ P u m p v i 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 v e l y
⇓ ⇓ ⇓ ⇓
⇓ ⇓ ⇓ ⇓ P u m p r e q u i r e s e x c e s s i v e p o w e r
⇓ ⇓ ⇓ ⇓
⇓ ⇓ ⇓ ⇓ P u m p l o s e s p r i m e a ft e r s t a 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 p a 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 v e r l i q u i d
⇓ ⇓ ⇓ ⇓ ⇓ ⇓ ⇓ ⇓
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CPX, CPXR, CPXN and CPXP USER INSTRUCTIONS ENGLISH 71569117 02-10
PROBABLE CAUSES
Pump not primed or filled with liquid.
Pump or suction pipe not completely filled with
liquid. (Where not a CPXP self priming
arrangement.)
Suction lift too high or level too low.
Insufficient margin between suction pressure and
vapour pressure.
Excessive amount of air or gas in liquid.
Air or vapour pocket in suction line.
Air leaks into suction line.
Air leaks into pump through mechanical seal,
sleeve joints, casing joint or pipe lugs.
Foot valve too small.
Foot valve partially clogged.
Inlet of suction pipe insufficiently submerged.
Speed too low.
Speed too high.
Total head of system higher than differential head
of pump.
Total head of system lower than pump design head.
Specific gravity of liquid different from design.
Viscosity of liquid differs from that for which
designed.
Operation at very low capacity.
Operation at high capacity.
Misalignment due to pipe strain.
Improperly designed foundation.
Shaft bent.
POSSIBLE REMEDIES
A. System troubles
Check complete filling.
Vent and/or prime.
Check NPSH > NPSH
A
losses at strainers and fittings.
Check and purge pipes and system.
Check suction line design for vapour pockets.
Check suction pipe is airtight.
Check and replace faulty parts.
CONSULT FLOWSERVE.
Investigate replacing the foot valve.
Clean foot valve.
Check out system design.
CONSULT FLOWSERVE.
CONSULT FLOWSERVE.
Check system losses.
Remedy or CONSULT FLOWSERVE.
Check and CONSULT FLOWSERVE.
Measure value and check minimum permitted.
Remedy or CONSULT FLOWSERVE.
Measure value and check maximum permitted.
Remedy or CONSULT FLOWSERVE.
B. Mechanical troubles
Check the flange connections and eliminate strains
using elastic couplings or a method permitted.
Check setting of baseplate: tighten, adjust, grout
base as required.
Check shaft runouts are within acceptable values.
CONSULT FLOWSERVE.
, proper submergence,
R
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