A diaphragm pump (also referred to as a Membrane pump) is a positive displacement pump that uses a mixture of the reciprocating action of a rubber, thermoplastic or teflon diaphragm and suitable valves on either side of the diaphragm

A double diaphragm is a positive displacement pump which utilises two flexible diaphragms that reciprocate back and forth, creating a short-term chamber, which both allures and expels fluid through the pump. … The two diaphragms that are connected by a shaft through the center section where the air valve is located.

Though it Air Diaphragm Pump depends upon the pump and application, a positive displacement pump, is normally a self-priming pump. … For instance, air operated diaphragm pumps self-primary by creating a pressure differential in the diaphragm chamber. This draws in air and pulls the liquid in to the suction port.