A positive displacement pump makes a liquid move by trapping a set amount and forcing (displacing) that trapped volume in to the discharge pipe. … Liquid flows into the pumpas the cavity on the suction aspect expands and the liquid flows out from the discharge because 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 is usually that positive displacement pumps will move liquid at the same rate regardless of the strain on the inlet end and centrifugal pumps will not