Flowserve TB-MAG INNOMAG - Manual (Page 37)

INNOMAG® TB- MAG™ ASME and ISO SEALLESS ENGLISH 26999988 06-14
Page 37 of 44
7 TROUBLESHOOTING
7.1 Faults, causes and remedies
The following is a guide to troubleshooting problems with Flowserve Innomag® TB-
MAG™ pumps. Common
problems are analyzed and solutions offered. Obviously, it is impossible to cover every possible scenario. If a
problem exists that is not covered by one of the examples, refer to one of the books listed in Section 10,
Additional Sources of Information, or contact a Flowserve sales engineer, distributor, or representative for
assistance.
FAULT SYMPTOM
P u m p o v e r h e a t s a n d s e i z e s

P u m p v i b r a t e s o r i s n o i s 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

POSSIBLE CAUSES POSSIBLE REMEDIES
A. System troubles
   Pump not primed or filled with liquid.
Check complete filling. Re-prime pump and verify that
suction pipe is full of liquid. Check the suction pipe for high
points that can trap air.
   
Pump or suction pipe not completely filled with
liquid.
Vent and/or prime.
 Discharge pipe clogged or valve shut.
Confirm that any discharge valves or control valves are not
stuck shut. Inspect discharge pipe for blockage.
   Suction pipe clogged or valve shut.
Confirm that any suction valves or control valves are not
stuck shut. Check strainer device. Inspect suction pipe for
blockage.
 
Head requirement higher than anticipated or
undersized impeller. (Pump casing and pipes
immediately before and after the pump heat up) Confirm than discharge line is not blocked or valve is not
stuck shut. Pump may require a larger impeller to overcome
system head.
  Clogged impeller Open pump and clear blockage from impeller.
  Clogged thrust balancing passages in impeller.
Open pump and clean blockage from grooves in between
impeller and bushings.
  Decoupled Impeller.
Shut off pump. Verify that the motor spins smoothly by hand.
If motor will not spin by hand, open pump for inspection. If
motor spins by hand, confirm that the impeller is sized for
operating conditions and liquid specific gravity.
Verify the viscosity of the liquid is not too high.
Note that the impeller and/or outer magnet may be
weakened if overheated.
  
Suction pipe volume too large for priming
chamber.
Calculate volume of the suction pipe. It is recommended
that the priming chamber volume should be 3 times the
suction pipe volume. Decrease suction pipe volume. Move
pump closer to source.
    Suction lift too high or level too low.
Check NPSH
A
> NPSH
R
, proper submergence, losses at
strainers and fittings.    
Insufficient margin between suction pressure and
vapor pressure.
    Excessive amount of air or gas in liquid. Check and purge pipes and system.