Centrifugal pumps convert mechanical energy (required to rotate the impellers) to hydraulic energy (required to lift a column of fluid). If applied improperly, operated outside the normal operating range, or poorly maintained, pump components will break down over time, leading to reductions in pump efficiency and pump failures.
It is vital to schedule pump preventive maintenance to avoid an unexpected breakdown of the equipment. Below are common points of failure in centrifugal pumps and the pump maintenance procedures required:
Ensure the bearings, lubricant levels, and lubricant quality are maintained in proper condition. Follow the pump manufacturer's guidelines for lubricant changes, lubricant type, and bearing operating temperature.
Excessive vibration in the bearings indicates an impending breakdown as it causes an unsustainable rise in temperature. If you notice excessive vibration in your centrifugal pump, you should have it checked out immediately. It could be a result of misalignment, cavitation, or normal wear.
A sudden decrease in the efficiency of your centrifugal pump may be due to a broken shaft seal. Leaks from a broken seal reduce the pump pressure required to lift a column of fluid. Inspect the shaft seals for any physical signs of damage/leakage and replace the seal where necessary.
An increase in the impeller to casing clearance can reduce the head pressure of the pump, negatively impacting pump discharge pressure. Routinely inspect impeller clearance and carry out clearance adjustments where necessary.
These standard maintenance procedures for centrifugal pumps can be carried out in accordance with the pump manufacturer's instruction manual. Normal maintenance intervals are quarterly, biannually, or annually depending on the type of pump application.
Following the pump manufacture's pump maintenance schedule will ensure that your centrifugal pumps are serviced when due to prevent costly downtime and expensive pump repairs.
How often do your centrifugal pumps require general maintenance or replacement of parts? What is a good time to schedule maintenance on the pumps to prevent downtime on operations? Asking these vital questions will help you to come up with a good strategy. However, be sure to create a maintenance schedule that is consistent with the manufacturer's guidelines.
As often as required, carefully inspect mounting points, seals and packing, pump flanges, filters, and couplings for signs of damage, leaks, or accumulation of grease, dirt, or debris to ensure that the pumps function optimally. Plan to replace parts as soon as problems occur by procuring spares.
Changing the lubricant in your centrifugal pump is essential to prevent damage of the bearings, but it must be scheduled according to the manufacturer's instructions. You might, however, want to increase the frequency of replacement if you use the pumps more frequently than indicated.
The electric motor is the powerhouse of the centrifugal pump. Since it contains both mechanical and electronic components, it requires frequent maintenance to function correctly. Include physical inspection and testing of the motor in your pump maintenance schedule to check for loose electrical connections, faulty windings, blocked vents, overheating problems, etc.