What Are The Common Faults Of Pipeline Centrifugal Pumps

Nov 29, 2025

1. Before starting the pipeline centrifugal pump, check if there is insufficient water filling or if the vacuum pump has not exhausted the air inside the pump. Extend the water filling time, increase the water filling volume, and continue to use the vacuum pump for pumping. If the water intake is still not fully filled and the air cannot be completely extracted, check whether the inlet pipe is leaking, whether the bottom valve is rusted, and whether the packing box is leaking. Repair or replace the problems identified during the inspection.
2. When the assembly head of the pipeline centrifugal pump exceeds the rated head of the water pump. The installation height of the water pump can be appropriately reduced (referring to the vertical distance between the pump shaft centerline and the well water level) or the length of the suction pipe can be shortened, and the diameter of the suction pipe can be increased (generally, the diameter of the suction pipe is one level larger than the inlet diameter of the water pump) to reduce the assembly head of the water pump and improve the suction height of the water pump.
3. The inlet pipe of the centrifugal pump in the pipeline leaks air, causing poor sealing, insufficient water intake, and incomplete air extraction. Inspection can be carried out using the illumination method. If there is a leak at the pipe wall, repair and seal it tightly; If there is a leak at the interface, tighten it with a wrench or replace the gasket.
4. The impeller of the pipeline centrifugal pump is reversed. The rotation direction of the water pump can be changed by changing the rotation direction of the power machine. If an electric motor is used as the power source, adjust the phase sequence of the motor wiring to change the direction of the motor; If an internal combustion engine is used as the power source, the adjustment is made by using the method of cross transmission of the transmission belt.

 

5. The depth of immersion of the suction pipe of the pipeline centrifugal pump into the water is not sufficient. Firstly, measure the depth of immersion of the suction pipe of the centrifugal pump into the water. If the immersion is too shallow, measures such as reducing the installation height of the water pump or increasing the length of the suction pipe of the centrifugal pump should be taken to ensure that the depth of immersion of the suction pipe of the water pump into the water surface is not less than 0.5 meters.
6. The inlet or impeller passage of the pipeline centrifugal pump is blocked. First, stop and check the specific blockage area, then remove the blockage. Depending on the type of blockage (such as mud, debris, etc.), measures such as washing the well (recommended to use an air compressor or other equipment) and setting up a trash rack can be taken to improve the water quality and prevent the blockage from happening again.
7. The bottom valve of the centrifugal pump in the pipeline is not flexible or rusted, causing the bottom valve to not open or close tightly. In this situation, the motor should be stopped first to lift the faucet of the water pump to the ground, remove the bottom valve for inspection, and repair or replace it according to the actual situation.
8. The suction capacity of the pipeline centrifugal pump is too high. Reduce the installation height of the water pump appropriately or try to minimize water pressure loss (such as using smooth inner wall inlet and outlet pipes).
9. The impeller of the pipeline centrifugal pump is severely damaged. Disassemble the water pump and remove the impeller for inspection. If the impeller is not severely damaged (worn or corroded), repair it; If the impeller is severely damaged, replace it with a new one.
10. Leakage at the packing box of the centrifugal pump in the pipeline resulted in poor sealing. First, use tools to tighten the stuffing box cover. If the fault cannot be eliminated, the packing box should be opened to check for any defects in the water seal ring and packing (such as twisted or deformed water seal ring, hardened or deformed packing, etc.), and repair or replace if necessary.

 

11. The fixing nuts and keys of the impeller of the pipeline centrifugal pump are loose or detached. Open the pump body and check the positioning key and locking nut of the impeller. If the key is dislodged or damaged, reset the positioning key or repair or replace the positioning key before resetting. If the impeller lock nut becomes loose or falls off, first assemble the lock nut and then use tools to tighten the impeller lock nut.
12. The speed of the pipeline centrifugal pump is too low. First increase the speed of the power machine, then check if the power supply voltage is too low. If it cannot reach the rated speed of the water pump, replace it with a higher power internal combustion engine. Or replace the transmission wheel of the power machine or water pump.
13. The resistance of the drainage pipe of the centrifugal pump in the pipeline is too high. First check the length and bends of the drainage pipeline, try to minimize the length of bends and pipelines, and choose pipelines with the same diameter as the water pump.