Double-diaphragm Air-operated pump

Double-diaphragm Air-operated pump is a reciprocating double-diaphragm, positive displacement type. The pump displaces fluid from one of its two liquid chambers upon each stroke completion. The following drawings and paragraphs detail the liquid flow pattern through the pump from its initial unprimed position.
There are a few wetted parts (parts that contact the fluid) which are dynamic:

The two diaphragms which are connected by a common shaft, the two inlet valve balls and the two discharge valve balls. The diaphragms act as a separation membrane between the compressed air supply and the liquid.
Driving the diaphragms with compressed air instead of the shaft balances the load on the diaphragm which removes mechanical stress and therefore extends diaphragm life. The valve balls open and close on the valve seats to direct liquid flow.

   

1 Air Chamber (Qty. 2) The air chamber is the chamber that houses the air which powers the diaphragms.

2 Air Distribution System The air distribution system is the heart of
the pump. The air distribution system is the mechanism that
shifts the pump in order to create suction and discharge strokes.

3 Outer Diaphragm Piston (Qty. 2) The outer diaphragm pistons provide

a means to connect the diaphragms to the reciprocating common
shaft and to seal the liquid side from the air side of the diaphragm.
4 Inner Diaphragm Piston (Qty. 2) The inner piston is located on the air
side of the pump and does not come into contact with the process
fluid.

5 Valve Ball (Qty. 4) Wilden air-operated pumps use suction and
discharge check valves to produce directional flow of process fluid
in the liquid chamber. The check valve balls seal and release on the
check valve seats allowing for discharge and suction of process fluid to occur.

6 Valve Seat (Qty. 4) The removable seats provide the ball valves a site to check.

7 Discharge Manifold Process fluid exits the pump from the discharge port located on the discharge manifold at the top of the pump.

8 Liquid Chamber The liquid chamber is filled with the process fluid during the suction stroke and -is emptied during the discharge
stroke. It is separated from the compressed air by the diaphragms.

9 Diaphragm The diaphragm membrane provides for separation of the process fluid and the compressed air power source. To perform
adequately, diaphragms should be of sufficient thickness and of
appropriate material to prevent degradation or permeation in specific process fluid applications. Wilden offers a variety of diaphragm materials for your specific application requirements. Turn to the elastomers section for more details.

10 Inlet Manifold Process fluid enters the pump from the intake port located on the inlet manifold at the bottom of the pump.