Positive Displacement Pumps:

Positive displacement pumps operate on a various principle than centrifugal pumps. It physically entraps a quantity of liquid at the suction of the pump and pushes in which quantity out the discharge of the pump.

A positive displacement pump is one in that a definite volume of liquid is delivered for every cycle of pump operation. That volume is constant regardless of the resistance to flow presented through the system the pump is in, given the capacity of the power unit driving the pump or pump elements strength limits are not exceeded. A positive displacement pump delivers liquid in divided volumes along with no delivery in among, although a pump having various chambers might have an overlapping delivery between individual chambers that minimizes this effect. It differs from centrifugal pumps that deliver a continuous flow for any provided pumps speed and discharge resistance.

Positive displacement pumps could be grouped into three basic types based on their design and operation. The three groups are rotary pumps, reciprocating pumps or diaphragm pumps.