Diaphragm Pumps for Fluid
Most diaphragm pumps used for handling beverages are air-operated double diaphragm (AODD) pumps. These pumps contain two chambers (diaphragms) made of flexible material, with a central piston between them. An external source of compressed air controls the speed that the piston moves back and forth. As the piston moves in one direction, it forces one of the diaphragms to expand and the other to contract. The expanding diaphragm pulls product into it, while the contracting diaphragm is squeezing product out. When the piston slides in the other direction, the diaphragms switch functions.
AODD pumps do not have an onboard motor or gearbox. Accordingly, they are often manufactured of thermoplastic, making them lightweight and low cost. They are extremely gentle on product and have a variable flowrate that can be controlled by adjusting the air pressure going into them. Because these pumps do require an external source of air to operate, they are usually used indoors where air compressors or central air supply are readily available. You’ll typically find them used with cartridge filter systems (often mounted on carts with the filter housings) for final stage / pre-bottling filtration.
