Air Operated Diaphragm Pumps (AODPS)

In general diaphragm pumps of all types are sealless pump, have no dynamic seals or packing, are self priming, and have an infinitely variable flow rate and pressure rate within the pressure and capacity ranges of the pump. Air-operated diaphragm pumps (AODPS) can also run dry indefinitely, and the discharge can be throttled to zero flow indefinitely.

The most common types of AODPs are the double diaphragm pumps (duplex pumps). These contain two diaphragm chambers and two desired flexible diaphragms. The diaphragm are connected to each other through a connecting rod and are clamped at the outer edges of the diaphragm. The shaft connected diaphragms move in the same linear direction simultaneously. Compressed air directed to the back side of the left diaphragm moves both right diaphragm. After complexion of a stroke, an air distribution valve directs compressed air from the supply to the back side of the right diaphragm and exhaust air to the atmosphere from the left chamber. This continuous reciprocating motion, along wit properly operating internal check valve, create an alternating intake and discharge of pumped liquid into and out of each chamber that result in a nearly continuous action from the combined chambers.

A discharge pump air motor contains an air distribution valve that shifts position at the end of each stroke of the pump. The air distribution valve alternatively directs supply air pressure to one chamber and exhaust the other. Air motor often use a two stage valve to control the reciprocating motion of the pump.