Diaphragm Pumps

The operating principle is compressed air moving two diaphragms alternately. With no shaft seal there is no conventional leak path; the pump is self-priming, is not damaged by dry running, and its flow rate is adjusted steplessly with air pressure. Because it contains no electric motor, it operates without electrical drive wherever a compressed air line is available.

Models in our catalog offer liquid connections from 1/4" to 3", maximum flow up to 1,050 l/min and air working pressure up to 8.4 bar. Discharge head reaches 84 m, and 168 m on heavy-duty series; dry suction lift is 3–6 m and wet suction lift around 9.8 m. Solids passage ranges from 1 to 12 mm depending on the model, with a viscosity limit between 5,000 and 55,000 cps.

Body materials are available in aluminum, cast iron, polypropylene, PVDF and 316/316L stainless steel. For diaphragms and wetted internals there are Neoprene, Buna-N, Viton, Santoprene, EPDM and Teflon alternatives. The right combination is determined by the chemical compatibility and operating temperature of the liquid to be transferred.

Flow rate, air consumption and diaphragm material are assessed together when selecting a model; for detailed criteria see our AODD pump selection guide, and for material compatibility our chemical compatibility chart. Alongside the Aflow and Seko series, spare parts compatible with Aro®, Blagdon®, Graco®, Sandpiper®, Versa-Matic®, Warman®, Wilden® and Yamada® are also supplied.