Air-operated double diaphragm (AODD) pumps are widely used across various industries due to their versatility and reliability, transferring nearly all types of liquid even without electricity. Since their introduction in 1955, AODD pumps have come a long way through advancements in technology.
AODD pumps are positive displacement pumps mainly used for transferring a wide range of products—from water to highly solid-laden liquids—with compressed air. An alternative to centrifugal pumps, sealless AODD pumps are used in industries such as oil and gas, food processing, chemical, paint, electronics, and pharmaceutical.
The continuous supply of air inside the pump results in the repetitive back-and-forth action of two flexible diaphragms connected to a rod. This constant motion drives liquid out of one chamber for discharge while filling the other chamber.
AODD pumps provide extra benefits that similar pumps do not, including the following:
In addition to AODD pumps' versatility, their ease of use and simple design are considered selling factors.
AODD pumps have no close-fitting, sliding, or spinning elements, thus requiring minimum assembly. Once installed, the pumps can function with less maintenance. They are referred to as "plug-and-play" pumps since they are ready to use as soon as they are attached to a compressed air connection.
AODD pumps can also run dry without causing damage to costly internal wear components or breaking an expensive motor. This means they don't fail or get clogged despite the lack of lubrication.
Finally, air-operated double diaphragm pumps are lightweight and portable—easy to dismantle, clean, maintain and repair compared with other types of industrial pumps with complex construction and parts.
Diaphragm pumps come with various levels of customisation. They are available in different sizes and materials depending on their purpose. These characteristics make AODD pumps useful in a wide range of applications that deal with diverse media, including clean and grey water, harsh chemicals, sewage, and naphtha. They can handle everything from water to 90 per cent solids with ease. Their customisable design also ensures costs are kept at a minimum.
Note that the working fluid greatly influences the pump material selection. For example, a small metal pump for moving water would be dissolved by strong acids. In this case, a plastic pump would be better. On the other hand, the flow rate requirement and potential pressure conditions will determine the correct pump size.
Air powers an AODD pump rather than fuel or electricity. A diaphragm pump is also hermetically sealed, thus minimising contamination risks. Additionally, diaphragm pumps are available with an ATEX (ATmosphères EXplosibles) certified version for use in applications where it is dangerous to use electricity.
AODD pump sizes range from 6.35 to 101.6 mm, with flow rates between 19 and 1,100 litres per minute. Manufacturers also offer a range of flexible sizes to provide users with a more suitable pump for their unique applications.
AODD pumps can generate flows as low as 4.5 litres per minute to as high as 1060 litres per minute. Standard duty air-operated double diaphragm pumps operate at a ratio of 1:1 with pneumatic pressures reaching up to 8.6 bar. However, users are given options of higher-pressure pumps of a 2:1 ratio with pressures reaching 16.5 bar. There is also the choice of a 3:1 ratio where pumps can achieve pneumatic pressures over 20.6 bar.
These are just some of the industries that trust AODD pumps to transfer liquids and viscous fluids:
All-Pumps has an extensive range of AODD pumps from the world’s most trusted manufacturers. Spare parts are also available for emergency cases. We also have trained and experienced staff who can be dispatched to the field to carry out quick and effective pump servicing.