Flowserve PLEUGER - Manual (Page 35)

PLEUGER STANDARD USER INSTRUCTIONS ENGLISH 71569293 01-13
Page 35 of 40
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9 FAULTS; CAUSES AND REMEDIES
FAULT SYMPTOM
Motor protection triggered

Pump does not start

Motor overheats

Unit runs but does not pump

Unit vibrates or is noisy

Motor loses filling liquid

Pump requires excessive power

Pump does not draw in water at start

Insufficient pressure developed

Insufficient capacity developed

PROBABLE CAUSES POSSIBLE REMEDIES
A. System problems
       Suction lift too high or level too low. Check NPSH
A
> NPSH
R
proper submergence.
    Excessive amount of air or gas in liquid. Check submergence. Losses on suction strainer.
  Pipe work defective. Leakage in pipe work. Check pipe work.
    Foot valve too small. Investigate replacing the foot valve.
  Foot valve partially clogged. Clean foot valve. Investigate replacing foot valve.
     
Inlet of suction housing insufficiently
submerged. Fitting depth inadequate. Check out system design. Install the unit
deeper.
    
Total head of system does not correspond to
pump characteristics.
Check discharge head and head losses in
discharge pipe at the valve settings. Check
back pressure is not too high.
  
Total head of system lower than pump design
head. Throttle at discharge valve or ask Flowserve if
the impeller can be trimmed.
 Specific gravity of liquid different to design. Consult Flowserve.
  Operation at very low capacity. Measure value and check minimum permitted.
    Operation at high capacity. Measure value and check maximum permitted.
     Slide valve closed. Pressure pipe not free. Check slide valve. Check piping.
B. Mechanical problems
 Improperly designed foundation.
Check setting of base plate: tighten, adjust,
grout base as required.
   Shaft bent. Check shaft run outs are within acceptable values.
    
Rotating part rubbing on stationary part
internally. Check for signs of this and consult Flowserve, if
necessary.
     Bearings worn. Replace bearings.
   Wearing ring surfaces worn. Touch up or replace worn wearing rings.
    Impellers damaged or eroded. Replace impellers and check for reason.
 Mechanical seal improperly installed.
Check alignment of faces or damaged parts and
assembly method used.

Incorrect type of mechanical seal for operating
conditions.
Consult Flowserve.
    
Shaft running off centre because of worn
bearings or misalignment.
Check misalignment and correct if necessary. If
alignment is satisfactory check bearings for
excessive wear.
 Impeller out of balance resulting in vibration. Check and consult Flowserve.