What to do if the head of the self priming pump is selected too high

Choosing a higher head for the self priming pump not only consumes excessive energy, but may also affect the lifespan of the self priming pump. To address this situation, first provide a solution based on the working principle of the pump:

1. Centrifugal self priming pumps. If the self suction pump is based on the centrifugal principle, it is actually a centrifugal pump that can self suction. Choosing a high head can pose a greater risk to the pump.

(1) Cutting the impeller of a self-priming pump: If the current head of the self-priming pump is too high and deviates significantly from the actual demand, and through calculation, if the pump's working efficiency and shaft power can be ensured to reach a reasonable range, the fastest method is to cut the impeller of the self-priming pump. Excessive cutting of the impeller will reduce the self suction performance of the pump.

(2) Adjusting working parameters: If it is inconvenient to replace the impeller, you can try adjusting the working parameters of the self suction pump, such as reducing the speed through frequency conversion, to reduce the head to a certain extent. But this method will also reduce the flow rate of the pump, and the feasibility needs to be determined based on the specific pump type and operating conditions.

(3) Increasing back pressure: By increasing the back pressure of the pump, such as closing some outlet valves, the flow rate of the self priming pump can be restricted, thereby reducing the head to a certain extent. But this method may lead to a decrease in pump efficiency.

(4) Adjustment of clearance: Self priming sewage pumps with open or semi open impellers can reduce pump parameters by adjusting the direct clearance between the impeller and the wear-resistant plate. Increasing the clearance will also reduce the suction head and flow rate of the pump, thereby affecting the overall efficiency of the pump.

2. A self priming pump with a volumetric capacity. If the head of a positive displacement pump is selected too high, except for excessive outlet pressure, it generally does not have an increased impact on the pump. Contrary to centrifugal pumps, a positive displacement pump uses a lower head and a smaller motor load

It should be noted that before making any adjustments or replacements, one should first understand the working principle and performance characteristics of the self priming pump, and choose a suitable solution based on the actual situation. Meanwhile, to ensure the safety and effectiveness of the operation, it is recommended to consult professional pump technicians or engineers for guidance and assistance.