A diaphragm pump (also called a Membrane pump) is a positive displacement pump that uses a mixture of the reciprocating actions of a rubber, thermoplastic or teflon diaphragm and suitable valves on either aspect of the diaphragm
A dual 
diaphragm is a positive displacement pump which utilises two flexible diaphragms that reciprocate backwards and forwards, creating a short-term chamber, which both allures and expels liquid through the pump. … The two diaphragms that are linked by a shaft through the center section where in fact the air valve is situated.
Though this will Air Diaphragm Pump depend upon the pump and application, a positive displacement pump, is normally a self-priming pump. … For instance, air managed diaphragm pumps self-prime by creating a pressure differential in the diaphragm chamber. This draws in surroundings and pulls the liquid into the suction port.