Is your centrifugal pump giving you problems?
The guidelines below might help or at least eliminate some of the more usual problems we experience in a callout:
- The centrifugal pump is not primed – re-prime the pump and check that the pump and suction line is full of fluid.
- The suction line is clogged – remove the obstructions.
- The impeller is clogged – backflush the pump to clean the impeller or remove and clean.
- The shaft is rotating in the wrong direction – change rotation according to the direction indicated by the arrow on the casing.
- The foot valve or suction pipe opening is not submerged enough – ensure adequate submersion and use baffle if suffering vortices.
- The suction lift is too high – shorten the suction pipe, relocate the pump closer to the source.
The pump is not producing the rated flow or head:
- The casing gasket or O Ring has an air leak – replace gasket or O ring.
- The stuffing box has an air leak – replace or re-adjust the packing or mechanical seal.
- The impeller is partially clogged – back flush to clean or remove to clean.
- The clearance between the impeller and casing is excessive – adjust the impeller clearance.
- The suction head is insufficient – ensure the suction line valve is fully open and line unobstructed.
- The impeller is worn or broken – inspect and replace.
The pump starts and then stops pumping
- The pump is improperly primed – re-prime the pump.
- The suction line has air or vapour pockets – re-arrange the piping to eliminate air pockets.
- The suction pipe has an air leak – repair the leak.
The bearings are running hot:
- The pump and driver are aligned improperly – realign the pump and driver.
- The lubrication has been applied improperly – check the lubrication for suitability and level
- The lubrication is cooled improperly – check the cooling system.
The pump is noisy or vibrates:
- The pump and driver are aligned improperly – realign the pump and driver
- The impeller is partially clogged – backflush or remove and clean
- The impeller or shaft is broken or bent – replace the impeller or shaft as necessary
- The foundation is not rigid – tighten the hold-down bolts of the pump and motor or adjust stilts
- The bearings are worn – replace
- The suction/discharge piping is not anchored/supported adequately – anchor/support correctly
- The pump is cavitating – locate and correct the problem
There is excessive leakage from the stuffing box:
- The packing gland is adjusted improperly – tighten the gland nuts
- The stuffing box is packed improperly – check or replace the packing
- The mechanical seal parts are worn or broken – replace parts or seal
- The mechanical seal is overheating – check the lubrication and cooling lines
- The shaft or sleeve is scored – machine or replace
To check if your problem is motor-related – Read our post on Pump Motor Overheating – Fault Finding Basics
Contact ESI Technologies Group if your problem is still not resolved and we will help you!