All pumping systems operating throughout the year encounter a great deal of stress, regardless of whether they operate under mild or harsh operating conditions. In order to ensure optimum reliability and performance, a centrifugal pump requires operating very close to its BEP or best efficiency point. This is the point at which a centrifugal pump has the minimum hydrodynamic unbalanced load.
Regardless of the operational environment, preventive maintenance of centrifugal pumps will extend the machine life while reducing the need for expensive repairs. Mentioned below is a basic preventive maintenance checklist for centrifugal pumps.
The performance of every pumping system must be examined and recorded thoroughly once every year. When a new pump is purchased, in the early stages of its operation, performance benchmarks should be established. Factors to be included in this benchmarking data are
- The head pressure as measured by the discharge and suction gauges.
- Flow rate of the centrifugal pump.
- Pump vibration signature
- Ampere draw of the motor.
Any changes noticed in these benchmarks during the annual maintenance should be recorded. This will help determine the required maintenance level to get the system back to its best efficiency point.
In addition to annual maintenance, it is important to perform certain maintenance tasks on a quarterly basis.
- Verification of the pump foundation’s integrity and checking the tightness of the hold-down bolts.
- In case of an oil-lubricated pump, the oil needs to be changed after the initial two hundred hours of operation. On the other hand, if the pump is grease-lubricated, the bearings should be greased every two thousand operating hours or three months, whichever comes first.
- Examine the pump’s shaft alignment.
- Grease the motor bearings as per the instructions of the manufacturer.
Tips for Bearing Lubrication:
Bearing lubrication is one of the most important aspects of operating and maintaining a centrifugal pump.
- Only non-foaming and non-detergent oils should be used for oil-lubricated bearings. Please remember that over-lubrication can be just as harmful as under-lubrication.
- Excess oil will lead to the generation of excess heat a slightly higher horsepower draw. This, in turn, causes frothing of the oil. While checking the lubrication oil, if you notice cloudiness, it may indicate the presence of excess water resulting from condensation. In such cases, immediate change of the oil is required.
- If your pump has re-greaseable bearings, do not mix greases of different consistencies and types. Also, please ensure that the shields are located towards the bearing frame’s interior. The bearing fittings must be absolutely clean while re-greasing so that there is no contamination.
- Please be mindful of the fact that over-greasing is harmful for the pumping system. This may lead to the generation of elevated temperatures in the races of the bearings, creating caked solids.
If you have any other questions related to your pumping system, please feel free to contact us at Tru-Flo Pumps. We provide the most efficient, reliable, and cost saving pump packages and solutions across a wide range of industries.