Self-priming pump suction is not enough what is the reason?

Self-priming pump suction is not enough what is the reason?

One of the common parts of the repair failure will cause suction deficiency:

1 is screw wear;

2, the motor capacitor capacity decreases, so that the speed decreases;

3 is the aging of the coil winding, speed decline (less than 2800 RPM, insufficient suction, motor heating fast, etc.).

The working principle of self-priming pump is: the pump starts before filling the pump shell with water (or there is water in the pump shell). After starting, the impeller rotates at high speed to make the water flow in the impeller groove to the vortex shell, then the inlet forms a vacuum, the inlet check door is opened, the air in the suction pipe enters the pump, and reaches the outer edge through the impeller groove. Self-priming pump is a self-priming centrifugal pump, which has the advantages of compact structure, convenient operation, stable operation, easy maintenance, high efficiency, long life, and strong self-priming capacity. There is no need to install the bottom valve in the pipeline, and only need to ensure that there is quantitative liquid injection in the pump body before working. Different liquids can use different materials of self-priming pump.