Flowserve APKD - Manual (Page 44)

APKD DOUBLE-CASE, DOUBLE-SUCTION USER INSTRUCTIONS 26999903 07-13
Page 44 of 55 flowserve.com
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
  P u m p w i ll n ot r u n
  P u m p vi b r a t e s o r i s n o i sy
  M e c h a n i c al s e a l h a s s h or t l i f e
  M e c h a n i c al s e a l le a k s ex c e s s i ve l y
  P u m p r e q u i re s e x c es s i ve p ow e r
  M o t o r O ve r l o a d e d
  I n s u f f i c i e n t p r e s s u r e d eve 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 ve r e d
  P u m p r u n s bu t d o e s n o t d e l i ve r l i q u i d
  POSSIBLE CAUSES POSSIBLE REMEDIES
A. SYSTEM PROBLEMS
   Pump not submerged. Check requirements/liquid level. Vent and/or prime.
    Impeller not adjusted or loose on shaft. Check impeller adjustment. See Section 5.3 for details.
   Suction lift too high or level too low.
Check NPSHa>NPSHr, proper submergence, losses at
strainers/fittings.
   
Insufficient margin between suction
pressure and vapor pressure.
   Excessive amount of air or gas in liquid. Check and purge pipes and system.
 Line check valve backward/stuck. Reverse chuck valve /free the valve.
 Unit running backwards. See start up instruction. Check motor phase/wiring
   Air or vapor pocket in suction line. Check suction line design for vapor pockets.
  Air leaks into suction line. Check suction pipe is airtight.
   
Intake strainer or impeller plugged or
pump in mud or sand. Start and stop several times or use line pressure if
available to back flush or pull pump to clean.
  
Inlet of suction pipe insufficiently
submerged.
Check out system design.
   Speed too low.
Consult Flowserve.
  Speed too high.
  
Total head of system higher than
differential head of pump.
Check system losses or consult Flowserve.

Total system head is lower than pump
design head.
 
Specific gravity of liquid different from
design.
Check the pump design for the type of liquid to be
handled. Consult Flowserve.
   
Viscosity of liquid differs from the
designed.
  Operation at very low capacity.
Measure. Check minimum permitted. Consult
Flowserve.
    Operation at high capacity.
Measure value and check maximum permitted. Consult
Flowserve.
B. MECHANICAL PROBLEMS
      Misalignment due to pipe strain.
Check the flange connections and eliminate strains
using elastic couplings or a method permitted.

Improperly designed foundation./Loose
fasteners. Check setting of base plate. Tighten, adjust, grout base
as required. Check fasteners and torque.
     Shaft bent. Check shaft run outs. Consult Flowserve.
     Rotating part rubbing on stationary part. Check. Consult Flowserve, if necessary.
     Bearings worn. Replace bearings.
   Wearing ring surfaces worn. Replace worn wear ring/surfaces.
   Impeller damaged or eroded. Replace. or consult Flowserve for an upgrade.