Flowserve 6LR-18A - Page 103

LR, LRV, LLR and LR-S USER INSTRUCTIONS ENGLISH 71569088 08-10
Page 35 of 48 flowserve.com
FAULT SYMPTOM
Pump overheats and seizes


Bearings have short life


Pump vibrates or is noisy


Mechanical seal has short life


Mechanical seal leaks excessively


Pump requires excessive power


Pump loses prime after starting


Insufficient pressure developed


Insufficient capacity delivered


Pump does not deliver liquid


PROBABLE CAUSES POSSIBLE REMEDIES
B. MECHANICAL TROUBLES
      Misalignment due to pipe strain.
Check the flange connections and eliminate
strains using elastic couplings or a method
permitted.
 Improperly designed foundation.
Check setting of baseplate: tighten, adjust, grout
base as required.
    
Shaft bent. Check shaft runouts 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. Replace worn wear ring/surfaces.
  
Impeller damaged or eroded. Replace impeller and check reason.

Leakage under sleeve due to joint failure. Replace joint and check for damage.
   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 satisfactory check bearings for
excessive wear.
   
Impeller out of balance resulting in vibration. Check and consult Flowserve.
  
Abrasive solids in liquid pumped. Check and consult Flowserve.
  Mechanical seal was run dry.
Check mechanical seal condition and source of
dry running and repair.
     
Internal misalignment due to improper repairs
causing impeller to rub.
Check method of assembly, possible damage or
state of cleanliness during assembly.
  
Excessive thrust caused by a mechanical failure
inside the pump.
Check wear condition of impeller, its clearances
and liquid passages.
 
Excessive grease in ball bearings. Check method of regreasing.
  Lack of lubrication for bearings.
Check hours run since last change of lubricant,
the schedule and its basis.
  Improper installation of bearings.
Check method of assembly, possible damage or
state of cleanliness during assembly and type of
bearing used.
  Damaged bearings due to contamination.
Check contamination source and replace
damaged bearings.
C. ELECTRICAL TROUBLES
   
Wrong direction of rotation. Reverse 2 phases on motor terminal box.
  
Motor running too slow. Check motor terminal box connections.