The lift of allweiler centrifugal pump drops during use. What happened? Alite Electromechanical Equipment Co., Ltd. should find out the reasons from the aspects of centrifugal pump parts, electrical equipment configuration, pipelines, etc.

(1) Impeller passage is blocked.

If the impeller channel is blocked, the operation of the impeller will be affected, thus affecting the lifting. Therefore, it is necessary to disassemble the pump to check and remove foreign matters. If necessary, filter the equipment before the centrifugal pump inlet.

(2) Internal leakage of allweiler centrifugal pump

When the clearance between the rolling part and the stationary part in the pump exceeds the planned range, it will lead to internal leakage, which is manifested in the decline of the discharge head of the pump, such as the clearance between the impeller ring and the multistage pump stages. Parts causing excessive clearance shall be overhauled for repair or replacement.

(3) Cavitation occurs at the inlet of allweiler centrifugal pump.

If the suction pressure of the allweiler centrifugal pump is too low, which is lower than the full steam pressure of the pumped medium, cavitation will occur. At this moment, check whether the inlet pipeline system is blocked or whether the opening of the inlet valve is too small, or add the liquid level of the suction pool.

(4) The head of allweiler centrifugal pump drops due to the speed reduction.

The important factors affecting the pump head are the impeller diameter and pump speed. Under other conditions, the head of the pump is proportional to the square of the speed. It can be seen that the speed has a great impact on the pump head. Sometimes, when the pump speed drops due to some external reason, the pump head will also drop accordingly.

(5) The operation point is transferred to high flow and low lift.

Generally, allweiler centrifugal pump has a continuous downward function curve, and the flow increases gradually with the decrease of lift. During operation, due to some reason, the back pressure of the pump drops, and the operating point of the pump moves passively to the low head and large flow point along with the curve of the equipment, which will result in the head drop. In fact, this is caused by external factors such as equipment changes, and has nothing to do with the pump itself. At this time, the problem can be solved by adding pump back pressure, such as closing the outlet valve.

(6) Reverse connection of motor

Due to the wiring, the rotation direction of the motor will be opposite to the actual required rotation direction of the pump. In general, first investigate the rotation direction of the pump when starting. If the steering direction is opposite, any two wires on the motor terminal should be replaced