Faults, Causes And Remedies - salmson NEX Manuel D'installation Et Mise En Service

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10 FAULTS, CAUSES AND REMEDIES
Faults Causes
‐ Pump not primed or filled with liquid
‐ Insufficient margin between suction pressure and vapor pressure
‐ Operation at very low capacity
Pump
‐ Misalignment due to pipe strain
overheats
‐ Rotating part rubbing on stationary part internally
and seizes
‐ Bearings worn
‐ Shaft running off center because of worn bearings or misalignment
‐ Impeller out of balance resulting in vibration
‐ Excessive thrust caused by a mechanical failure inside the pump
‐ Operating at high capacity
‐ Misalignment due to pipe strain
‐ Shaft bent
‐ Rotating part rubbing on stationary part internally
‐ Bearings worn
‐ Shaft running off center because of worn bearings or misalignment
Bearings
have short
‐ Impeller out of balance resulting in vibration
life
‐ Excessive thrust caused by a mechanical failure inside the pump
‐ Excessive grease in ball bearings
‐ Lack of lubrication for bearings
‐ Improper installation of ball bearings (damage during assembly, incorrect
assembly, wrong type of ball bearings etc )
‐ Damaged bearing due to contamination
‐ Motor running too slow
‐ Pump or suction pipe not completely filled with liquid
‐ Suction lift too high or level too low
‐ Insufficient margin between suction pressure and vapor pressure
‐ Foot valve too small
‐ Foot valve partially clogged
‐ Inlet of suction pipe insufficiently submerged
‐ Operation at very low capacity
‐ Operating at high capacity
‐ Misalignment due to pipe strain
‐ Improperly designed foundations
Pump
‐ Shaft bent
vibrates or
‐ Rotating part rubbing on stationary part internally
is noisy
‐ Bearings worn
‐ Impeller damaged or eroded
‐ Shaft running off center because of worn bearings or misalignment
‐ Impeller out of balance resulting in vibration
‐ Excessive thrust caused by a mechanical failure inside the pump
‐ Excessive grease in ball bearings
‐ Lack of lubrication for bearings
‐ Improper installation of ball bearings (damage during assembly, incorrect
assembly, wrong type of ball bearings etc )
‐ Damaged bearing due to contamination
‐ Wrong direction of rotation
‐ Motor running too slow
‐ Misalignment due to pipe strain
‐ Shaft bent
‐ Bearings worn
‐ Shaft sleeve worn or scored or running off center
‐ Mechanical seal improperly installed
‐ Incorrect type of mechanical seal for operating conditions
Mechanical
‐ Shaft running off center because of worn bearings or misalignment
seal has
short life
‐ Impeller out of balance resulting in vibration
‐ Abrasive solids in liquid pumped
‐ Internal misalignment of parts preventing seal ring and seat from mating
properly
‐ Mechanical seal was run dry
‐ Internal misalignment due to improper repairs causing impeller to rub
‐ Misalignment due to pipe strain
Mechanical
Remedies
Check for complete filling
> NPSH
Check NPSH , proper submergence, losses at strainers and
A R
fittings
Measure the value and check minimum permitted.
Remedy or call Salmson
Check the flange connections and eliminate strains using elastic
couplings or a method permitted
Check and consult Salmson if necessary
Replace bearings
Check misalignment and correct it if necessary. If alignment satisfactory
check bearing for excessive wear
Check and consult Salmson
Check wear condition of impeller, its clearances and liquid passages
Measure the value and check maximum permitted.
Remedy or call Salmson
Check the flange connections and eliminate strains using elastic
couplings or a method permitted
Check shaft runouts are within acceptable values
Consult Salmson
Check and consult Salmson if necessary
Replace bearings
Check misalignment and correct it if necessary. If alignment satisfactory
check bearing for excessive wear
Check and consult Salmson
Check wear condition of impeller, its clearances and liquid passages
Check method of regreasing
Check hours ruin since last change of lubricant, the schedule and its
basis
Check method of assembly, possible damage or state of cleanliness
during assembly and type of bearing used. Remedy or consult Salmson if
necessary
Check contamination source and replace damaged ball bearings
Check motor terminal box connections and voltage
Vent and /or prime
> NPSH
Check NPSH , proper submergence, losses at strainers and
A R
fittings
> NPSH
Check NPSH , proper submergence, losses at strainers and
A R
fittings
Investigate replacing the foot valve
Clean the foot valve
Check out system design
Measure the value and check minimum permitted.
Remedy or call Salmson
Measure the value and check maximum permitted.
Remedy or call Salmson
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 Salmson
Check and consult Salmson if necessary
Replace bearings
Replace or consult Salmson for improved material selection
Check misalignment and correct it if necessary. If alignment satisfactory
check bearing for excessive wear
Check and consult Salmson
Check wear condition of impeller, its clearances and liquid passages
Check method of regreasing
Check hours ruin since last change of lubricant, the schedule and its
basis
Check method of assembly, possible damage or state of cleanliness
during assembly and type of bearing used. Remedy or consult Salmson if
necessary
Check contamination source and replace damaged ball bearings
Reverse two phases at motor terminal box
Check motor terminal box connections and voltage
Check the flange connections and eliminate strains using elastic
couplings or a method permitted
Check shaft runouts are within acceptable values
Consult Salmson
Replace bearings
Check and renew defective parts
Check alignment of faces or damages parts and assembly method used
Consult Salmson
Check misalignment and correct it if necessary. If alignment satisfactory
check bearing for excessive wear
Check and consult Salmson
Check and consult Salmson
Check and consult Salmson
Check mechanical seal condition and source o f dry running and repair
Check method of assembly, possible damage or state of cleanliness
during assembly.
Remedy or consult Salmson if necessary
Check the flange connections and eliminate strains using elastic
couplings or a method permitted
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