Air Operated Double Diaphragm Pump
The AODD pump is double pumps in one. Chambers A & B are alternatively filled and emptied by drawing liquid in through a common inlet © and out through a common outlet (D). The Diaphragms in each chamber are connected by a common shaft so that they move., backwards together. Compressed dry air is directed by the air valve (E) alternatively behind each diaphragm to power discharge strokes. Pump speed and therefore fluid flow-rate can be infinitely controlled by increasing or decreasing or decreasing air pressure and or volume.
The Blue arrows show the pump cycle. Fluid is being drawn into inlet ( c) by the suction stroke of the diaphragm in chamber B, which opens the ball valve (1) to allow liquid to enter the chamber ,Ball valve (3) is closed by the diaphragm suction.
In chamber (A) air has been applied to the rear of the diaphragm to force out the liquid in the chamber through the Ball Valve (4) to the Liquid outlet (d). This discharge stroke closes Ball valve (2) to prevent further liquid entering the chamber. This cycle is repeated to provide a continuous flow o outlet D.
Standard AODD pumps are one : One ratio-maximum outlet pressure never exceed air supply pressure.