An air operated pumps operates from 1 to 7 bar pressurized air.
The compressed air is directed by the air distributor sometimes in the left air chamber, sometimes in the right air chamber. The air side chambers are separated from the liquid side chambers by two flexible membranes interconnected by a shaft.
When the distributor sends the compressed air into the right chamber, the air contained in the left chamber is evacuated through an exhaust silencer. The air presses on the right-hand membrane and the volume of the right-hand liquid-side chamber decreases; this creates a pressure that closes the bottom valve and pushes the liquid into the discharge manifold through the top valve. At the same time the tree goes to the right and pulls on the left membrane. Thus the volume of the liquid side chamber on the left increases; it creates a depression, the bottom valve is lifted and the liquid is sucked by the suction manifold.
At the end of the stroke, the air distributor changes direction and sends the air into the chamber on the right air side; the process described above is reversed.
Components of an air operated pumps
The valve guides are fully independent and modular, replacement is easy and inexpensive without having to change the manifolds.
Ball valves or pellets depending on the type of pump are available in different materials including PTFE.
The valve seats are also interchangeable and can be changed in another material such as stainless steel or others.
The dispenser spindle is easily accessible from the outside and can be removed by hand in a few seconds instead of replacing the complete system, it is possible to change only the O-rings. The air distributor is self-lubricating and therefore does not require grease or lubricating oils under normal operating conditions.
Both drivers can also be changed separately, their design is robust and reliable protects the air distributor from premature wear. Both bearings allow a good pilot guidance and are removable in case of wear. The two membranes are the spare parts in contact with the liquid, these are the most stressed components, particular care must be taken in the choice of their material; available in EPDM, Viton, Santoprene, PTFE.