WZB series vortex self-priming pump

Self-priming is the ability to suction the air in the inflow channel as the pump is being started.

After installing the pump and before starting it, its body must be filled with water; once started, the rotary movement of the impeller creates a flow in the liquid present inside the pump body.

The physical principle of self-priming therefore consists in the strong depression generated at inflow. The principle is known as the Nozzle-Venturi system: the impeller suctions the water which, passing through the nozzle, increases in speed; after this, the speed decreases as the water passes through the Venturi pipe, this fast variation generates a depression inside the suction pipe. This depression allow to remove the air in the suction pipe ant the raises of the liquid level inside the inflow pipes.