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

A dual 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. … Both diaphragms that are connected by a shaft through the centre section where in fact the air valve is located.

Though this will depend upon the pump and Air Diaphragm Pump application, a positive displacement pump, is generally a self-priming pump. … For instance, air managed diaphragm pumps self-primary by creating a pressure differential in the diaphragm chamber. This draws in atmosphere and pulls the liquid in to the suction port.