A positive displacement pump makes a fluid move by trapping a set amount and forcing (displacing) that trapped volume into the discharge pipe. … Liquid flows in to the pumpas the cavity on the suction side expands and the liquid flows out of the discharge as the cavity decreases.

The most typical type among centrifugal pump may be the radial flow pump. … The main difference between these types of pumps and centrifugal can be that positive displacement pumps will move fluid at the same acceleration regardless of the strain on the inlet end and centrifugal pumps won’t