Air-operated double-diaphragm pumps (AODD) have been through many innovations in technology and design since their introduction to the market more than six decades ago. They are now a key player in the pump selection process. AODD pumps offer a seal less, positive displacement alternative to centrifugal pumps. They are used for a number of applications across a wide range of industries including oil and gas, food processing, chemicals, paints, electronics and pharmaceuticals. AODD pumps is that they are easy to use. The simple design combined with the ability to pump most materials makes them a popular option.

AODD pumps do not have any close-fit, sliding or rotating parts and, as a result, require minimal assembly. Many refer to these pumps as “plug-and-play” items because, once they are connected to a compressed air line, they are ready to use immediately. Once in place, the pumps can effectively run with little maintenance. The AODD pumps are able to run dry without damaging costly internal wear parts or destroying an expensive motor. Also, the pumps do not use oil or other lubricants, which means they do not stall or get clogged because of lack of lubrication. A useful feature is that they can be dead headed without damage to the pump. Also, if a system is programmed to shut down the pump when certain pressures have been reached (a filter press application, for example), it can do this safely without incurring huge repair bills for broken pumps.

Another advantage of an AODD pump is that they are lightweight and portable, making them ideal for use in multiple locations. They are also easy to dismantle, repair, clean and maintain compared with other types of pumps with a more complex construction that have multiple electrical components and parts. This simplicity ensures the production line continues to run smoothly, provided that regular pump maintenance is scheduled. AODD pumps do not require electricity or any fuel other than compressed air. This intrinsically safe design means that no harmful fumes are exhausted, eliminating the risk to the workers and product. Furthermore, they are fully sealed units, meaning they can be partially or completely submerged in a liquid. This minimal risk of contamination provides an added benefit to the food and beverage industry.

AODD pump sizes range from 0.25 to 4 inches, with flow rates ranging between 19 and 1,100 liters per minute. Today, manufacturers offer a range of flexible sizes, enabling users to buy a pump that will give them a balanced system. ODD pumps are capable of pumping as slow as 1 gallon per minute. Of course, a 3-inch pump will carry a higher capital investment, but the returns can be exponential when it comes to productivity gains from using a larger pump.

Another benefit of AODD pumps is that standard units are 1-to-1 ratio pumps. When a discharge pressure of more than 125 pounds per square inch (psi) is required, users can opt for a 2-to-1—or even a 3-to-1—ratio pump unit which can exceed pressures of 300 psi.