Air-Operated Double Diaphragm Pump 1 Inlet Outlet Petroleum Fluids 35GPM 120PSI Product Description: A diaphragm pump (also known 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 side of the diaphragm (check valve, butterfly valves, flap valves, or any other form of shut-off valves) to pump a fluid. The listing is about 35 GPM Air-Operated Double Diaphragm Pump with 1 Inch Inlet And Outlet. This powerful air-operated double diaphragm pump QBY4-25L features a 1in. Outlet capable of pumping up to 35 gallons/min at temperatures up to 150 degrees F. Application: Perfect for use with water. Ideal for use with low viscosity petroleum fluids inclu.