Maintenance Of Centrifugal Pump

Centrifugal pump maintenance is very essential if you want to ensure it works with maximum efficiency.


Like every pump, a centrifugal pump needs to be maintained to prevent it from failing and also for the longevity of the pump.


In this article, I will share with you how you can maintain a centrifugal pump to ensure its efficiency is kept to the brim.


The main issue that will give you a headache when it comes to maintaining a centrifugal pump is the rotor.


And we all that if the rotor of the centrifugal pump fails, it will render the pump useless.


Without wasting so much time, let me share with you what you need to know about the maintenance of a centrifugal pump.


Maintenance of centrifugal pump;

1. Lubrication of the moving parts.

Lubrication of centrifugal pump is very important since a rotor is in charge of the pumping mechanisms.


Failure of the rotor then the pumping mechanisms won’t work anymore.


If you want to know the working principle of a centrifugal pump, check the article below.


You might like this: Centrifugal Pumps: Types, Working Principle, Uses & Advantages


You should ensure that the moving parts of the centrifugal pump are well lubricated if you want it to work effectively.


The oil level matters when it comes to the functioning of this pump.


If you either use less or more lubrication than required by the manual then you will interfere with the working condition of the pump.


Ensure that the oil level is at the correct distance from the shaft centreline.


The lubricant is very essential as it is also used in regulating the temperature of the centrifugal pump.


The oil you use to lubricate the moving parts of the pump also serves as a cooling agent preventing the pump from overheating.


If the bearing’s temperature is too high then you should add more lubricant to the bearings to enable sufficient heat distribution within the bearing hence decreasing the temperature of the bearings.


Ensure that the lubricant used in the centrifugal pump doesn’t have any sign of bubbling at all.


If there is bubbling then know that the temperature on the bearings is too high and you should add more lubricant to decrease it.


And this will keep your centrifugal pump in the right condition.


2. Checking the bearings.

Maintenance of the bearing is also very important when it comes to the efficiency of the centrifugal pump.


The bearings aid in the rotation of the impeller within the pump, if they have any fault this will decrease the working capacity of the pump.


If the bearings are in good condition then the rotation of the impeller will be very smooth.


You will not come across excessive vibrations and noises when the centrifugal pump is operating.


The moment you get different noises coming from the centrifugal pump while it’s operating, this should tell you that the bearings have an issue.


They can be worn out and that is why they create noise and excessive vibrations as the impeller is rotating.


When this is the case, then you will have to replace the worn-out bearings for the centrifugal pump to work smoothly.


If you have checked your oil level and it’s at the correct level and you should get the noises when the pump is operating, disassemble the pump and check on the bearings.


3. Shaft seal condition.

Shaft seal condition also matters when it comes to the efficiency of the centrifugal pump.


If the mechanical sealing of the shaft is not in the right order then this will end up messing with the pumping capacity of the pump.


You should check the mechanical seal and ensure that there are no visible leakages.


The moment there is a leakage this will make the centrifugal pump consume much power and the capacity of its pumping mechanism will be low.


if the mechanical seals of the shaft are loose ensure that they are well tightened to prevent leakages.


4. Overall pump vibration.

When a centrifugal pump is operating you will get the vibrations simply because of the forces that are transmitted from the pump to the surroundings.


If the centrifugal pump is vibrating this shows that it’s in good working condition.


But the moment you will experience excessive vibrations coming from the pump then this should tell you something is wrong with either the pump or the accessories.


If excessive vibrations are coming from the pump check on the following thing;

  1. Ensure the centrifugal pump shaft is in the correct alignment since any misalignment will cause the problem of excessive vibrations from the pump.
  2. The part you should check is the bearings, bearings failure of the centrifugal pump will result in excessive vibration since there is no smooth movement of the shaft within the pump.
  3. Check the pump and ensure there is no cavitation since this can also result in excessive vibrations when the pump is operating.
  4. Ensure the suction and the discharge line of the centrifugal pump is in the correct working condition.


Clean the suction and delivery valve of the pump if they are clogged as this can also cause excessive vibrations in the centrifugal pump.


If there is cavitation you should create a short suction line with the largest possible cross-section.


The vibration of the pump is very important for analysis since it will give you an idea if the pump needs further maintenance or not.


You might like this: Advantages & Disadvantages Of Vibration In Machines


5. Hold-down bolts of the centrifugal pump.

Don’t focus too much on the internal parts of the pump and forget the external parts of the pump.


The external parts are also very important when it comes to how the centrifugal pump will work.


If the centrifugal pump is tightly held against the place it’s supposed to be operating then this will not cause any problem with the working of the pump.


The moment the hold-down bolts of the centrifugal pump are loose then the pump will not be stable in its position.


This can result in great damage to the pump, especially the suction line and the delivery line may be disconnected.


When this happens then the working of the pump will be interfered with since there is no way it will pump liquid if the suction line and delivery line are disconnected.


To prevent this from happening, ensure that the bolts used to hold the centrifugal pump against where it’s working are fastened tight enough.


When you tighten the holding bolts of the centrifugal pump you will save yourself from bigger the bigger cost of maintenance of the centrifugal pump.


6. Shaft alignment of the centrifugal pump.

Ensure that the shaft alignment of the centrifugal pump is correct if you want to prevent most of the problems coming from the vibrations and discharge pressure of the pump.


The shaft should be in the correct alignment to ensure the impeller rotates perfectly.


If the shaft has a misalignment of any kind, this will interfere with the impeller movement.


Also, since the shaft is not in the correct alignment there will be a problem with its connection to the bearings.


The moment there is a misalignment of the shaft in the centrifugal pump excess vibrations and noises will be coming from the pump as it operates.


It will decrease the pumping efficiency of the pump and if not fixed it will result in its failure.


So, the moment you notice any misalignment of the shaft you should ensure that you set it right.


When you do that you will be saving yourself from a lot of problems resulting from the pump impeller rotation.


7. Check on the casing of the pump.

Don’t forget to check on the centrifugal pump casing since it’s also very important when it comes to pressure discharge of the liquid.


If at any point the casing has an issue, this will interfere with the pressure discharge of the pump.


The casing of a centrifugal pump is commonly affected by corrosion and wear.


If you find that the corrosion of the casing is beyond repair or maintenance, you should replace the casing.


Leaving a casing that is corroded may interfere with the working of the pump not only the discharge pressure.


Think about it, the moment any filling particles from the corroded part of the casing get clogged in the rotor of the pump then this will jam the pump.


The centrifugal pump won’t work if the rotor won’t be rotating.


If that is not what will happen, the pressure discharge of the liquid will be lower than the expected value.


So, if the casing is affected by wear and corrosion you should replace it immediately.


8. Check on the impeller.

The impeller ensures the suction and discharge of the liquid from the centrifugal pump.


If at any point the impeller is not working the way it should then the pump capacity and efficiency will decrease.


The common issue that affects the impeller blades of the centrifugal pump is corrosion.


Corrosion is the biggest enemy of the impeller blades. If you find that the impeller blades are corroded you should replace them.


The other problem that you may come across as you check the centrifugal pump impeller is the wear of the blades.


The only thing you should do when there is wear on the impeller blades is to replace them.


As this has a great impact on the overall capacity of the pump.


9. Bearing housing of the centrifugal pump.

Check on the bearing housing of the centrifugal pump and ensure it’s in the right condition.


These are some of the common problems you may come across when checking the bearing housing of a centrifugal pump;

  1. Corrosion of the bearing housing.
  2. Wear of the housing is caused by the rotation of the bearings and shaft.
  3. You will also spot cracks or pits on the bearing housing.


If you come across these issues then you should think of replacing the bearing housing.


10. Cleaning of the centrifugal pump.

Once in a while, you will have to think of cleaning the centrifugal pump.


Failure to cleaning of the pump, you might spend so much on maintaining the pump.


The suction line of the pump may be clogged by dirt if you don’t clean the pump.


Also, the valves will never work if they are dirty since they will restrict the inlet and discharge of liquid from the pump.


If at any point debris attaches itself to the impeller, they might jam it and the pump won’t work.


To prevent all these problems from happening you have to ensure you regularly clean the pump.


Dissemble the whole pump and clean every part and change the lubrication too and assemble it tightly.


When you do this, you will be maintaining your pump and it will always be in good working condition.


If you have any questions leave your comment, thank you for reading and see you in my next article.


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