Basically, there are two types of pumps: A Centrifugal Pump B: Positive Displacement pump!

Positive Displacement = rotary lobe pump, progressive cavity pump, rotary gear pump, piston pump, diaphragm pump, screw pump, gear pump, Hydraulic pump, vane pump

Centrifugal Pumps = end-suction pumps, in-line pumps, double suction pumps, vertical multistage pumps, horizontal multistage pumps, submersible pumps, self-priming pumps, axial-flow pumps, regenerative pumps.

The Single-stage pump has one impeller and the multi-stage pump has two or more impellers in series!

In this pump design, all rotating parts (shaft, rotor, impeller) are located within the can in the pumped medium. Cooling and lubrication are provided by the pumped medium.

Cavitation means bubbles are forming in the liquid.
To avoid cavitation, we have to increase the pump size to one or two Inch;
To increase the pressure of the Suction Head, or decrease the pump speed.

The formation of cavities (or bubbles) is induced by flow separation, or non-uniform flow velocities, inside a pump casing.
In centrifugal pumps, the eye of the pump impeller is smaller than the flow area of the pipe. This decrease in flow area of the pump results in an increase in flow rate.
So pressure drop happened between the pump suction and the vanes of the impeller.
Here air bubbles or cavities are formed because of liquid vapour due to an increase in temperature in the impeller. These air bubbles are transmitted to the pump which forms cavitation.

The higher it is, the quicker it pumps. A range of 100-200 LPM is usually sufficient for a household.
Head Range – Head here refers to the discharge head – the vertical distance that you will be pumping the water.
The head range should fall within this distance for the water pump to pump water effectively.

A drainage pump is primarily intended for pumping surface water and seepage to different locations, and for the pumping of groundwater.

Wastewater pumps on the other hand are primarily used to dispose of wastewater. This includes e.g. pumping wastewater out of collector pits and pumping station applications.