Centrifugal pumps are widely used in modern industrial production, and some problems may arise during use. To solve the problem, it is necessary to first understand the cause of the malfunction and then take appropriate measures.
1, After starting up, the pump cannot produce liquid.
(1) There is air in the inlet pipe and pump.
The centrifugal pump was not filled with water before starting, and the air inside the pump was not completely discharged; The packing of the centrifugal pump is worn or not tightly packed, causing liquid to spray out from the gap between the packing and the pump shaft sleeve, and air to enter the gap, affecting the outflow of water; Damage, cracks, or holes in the inlet pipe can cause air to enter.
Solution: Before starting, slowly inject liquid through the injection hole on the pump cover (to facilitate air discharge) and replace damaged parts.
(2) The centrifugal pump has a low rotational speed.
Some users have damaged the original motor and randomly installed another motor. If the motor speed is insufficient, it will cause a decrease in water pump flow and pressure; Loosening of the fastening nut between the impeller and the pump shaft, deformation and bending of the pump shaft, direct friction between the impeller and the pump, or damage to the bearing can all affect the speed; The motor winding is destroyed and demagnetized, resulting in insufficient power.
Solution: The motor speed or voltage should be checked to determine if it is too low. Check if it is a motor or pump malfunction and replace it promptly.
(3) Centrifugal pump exceeds suction capacity.
The installation position of the centrifugal pump is too high and the suction height is too high, exceeding the suction stroke of the pump. The negative pressure generated inside the centrifugal pump cannot pressurize the liquid to a certain height. When selecting and installing, the suction stroke of the pump must be considered, otherwise cavitation may occur and damage the pump components.
Solution: Reinstall, lower the height, or immerse the pipe into the pool.
(4) The filter is clogged and the bottom valve is not functioning properly
The filter screen is blocked by debris, and the bottom valve gasket is stuck or rusted.
Solution: Check the filter screen and eliminate debris.
2, Centrifugal pump vibration and abnormal noise.
(1) The base is loose and unstable.
When vibration occurs, first check whether the foundation bolts of the centrifugal pump are tightened, and also consider whether the foundation strength is sufficient.
Solution: Tighten the bolts again.
(2) Cavitation phenomenon occurs.
During the cavitation process, bubbles and bubbles will rupture, causing vibration and noise in the centrifugal pump.
Solution: Change the installation height or increase the system pressure, and even choose or design the pump again.
(3) The rotor balance decreases.
When the rotor is unbalanced, the deviation between the center of gravity and the center of rotation of the rotor is too large, resulting in unbalanced force during rotation. When the speed is high, the vibration is more pronounced. The manufacturing or assembly process of rotor imbalance may not meet the design requirements; After running for a certain period of time, the rotor balance accuracy of the centrifugal pump decreases due to shaft deformation, excessive eccentric wear of parts, and other reasons.
Solution: Rebalance the rotor.
(4) Impeller flow channel blockage.
There are foreign objects blocking the impeller flow channel, causing the impeller to be heavy and unevenly stressed.
Solution: Remove the impeller for cleaning.
(5) Reasons for bearings.
If the bearing is damaged, in addition to increasing its own operating noise, it will cause the rotor's motion to lose stability, resulting in increased vibration and noise of the pump unit. In addition, excessive radial clearance of the bearing may also cause abnormal noise.
Solution: Replace the bearing.
