Draw the centrifugal pump diagram and show the impeller and fluid flow direction

Centrifugal pump is as shown in the figure.

In this figure observe the vanes shape and impeller direction.

Volute: It is the gap between the casing and the impeller. There are two uses with volute of the centrifugal pump.

1. In this volute kinetic energy is converted into pressure energy. As the cross section area increases, the volute reduces the velocity of the liquid and increases the pressure of the liquid.
2. One of the main purposes of a volute casing is to help balance the hydraulic pressure on the shaft of the pump. However, this occurs best at the manufacturer's recommended capacity. Running volute-style pumps at a lower capacity than the manufacturer recommends can put lateral stress on the shaft of the pump, increasing wear-and-tear on the seals and bearings, and on the shaft itself.

Centrifugal pumps are used for large discharge through smaller heads.