Diaphragm pumps are positive displacement pumps that use a flexible membrane, the diaphragm, to move fluid. They handle everything from clean water to highly viscous slurries, aggressive chemicals, and shear-sensitive pharmaceutical products, making them one of the most versatile pump types available.
At TF Pumps, we supply air-operated diaphragm pumps (AODD pumps) from Graco, Aro, Dellmeco, Yamada, and Enviroflex, in materials ranging from aluminium and cast iron to stainless steel, polypropylene and PTFE. We also supply electric diaphragm pumps on a dedicated page. Browse our AODD ranges below, or call us on +44 1332 913500 for help selecting the right pump for your application.
A diaphragm pump uses a flexible membrane that flexes back and forth to create suction and discharge strokes, drawing fluid in through an inlet valve and pushing it out through a discharge valve. Because the diaphragm seals the pumped fluid away from the pump’s mechanical components, diaphragm pumps can handle corrosive, abrasive, viscous and shear-sensitive liquids without contamination or damage to the drive mechanism.
This sealed design also means diaphragm pumps can run dry without damage, self-prime from dry, and are inherently leak-free, critical advantages in chemical, pharmaceutical and food-grade environments. For a full technical explanation of the pumping cycle, see our guide: How Do Diaphragm Pumps Work?
Air operated diaphragm pumps, commonly known as AODD pumps, use compressed air to drive the diaphragms. An air distribution valve alternates air pressure between two diaphragm chambers: as one diaphragm is pushed outward on its discharge stroke, the other is pulled inward on its suction stroke. Four check valves (ball or flap) direct fluid through the pump.
AODD pumps are the most popular type of diaphragm pump in industrial service because they are intrinsically safe (no electrical components in the fluid path), can run dry indefinitely, are self-priming to several metres of suction lift, and handle viscosities up to 30,000 cPs. They are available in sizes from ¼” to 3″ porting and in a wide range of body and diaphragm materials to suit virtually any fluid.
For a comparison between air and electric drive options, see our blog: Air Operated vs Electric Operated Diaphragm Pumps.
The diaphragm itself is the key wear part and must be compatible with the fluid being pumped. Common diaphragm materials include Neoprene, Nitrile, EPDM, Santoprene, Hytrel, Viton and PTFE, each suited to different chemical families, temperatures and abrasion levels. Selecting the right diaphragm material is critical to pump life and performance. Use our Diaphragm Selector tool to find the right material for your fluid, or call us for advice.
Diaphragm pumps are available in a range of body materials to match the application:
Many of the diaphragm pumps we supply carry industry certifications, including ATEX (for use in explosive atmospheres), FDA and 3A (for food and pharmaceutical contact), and EHEDG (European hygienic equipment design). We can advise on which certifications your application requires.
Selecting a diaphragm pump starts with four questions: what fluid are you pumping (chemical composition, viscosity, solids content, temperature), what flow rate do you need, what discharge pressure does the system require, and what air supply is available (pressure and volume). From there, pump size, body material and diaphragm material can be specified.
As an experienced diaphragm pump supplier we stock AODD pumps from Aro, Dellmeco, Enviroflex, Graco and Yamada, giving us the range to match the right pump to the job rather than forcing a fit from a single brand. Call us on +44 1332 913500 with your application details and we’ll recommend the right model.
These guides from our blog cover diaphragm pump technology in more depth:
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A diaphragm pump is a positive displacement pump that uses a flexible membrane (the diaphragm) to move fluid. The diaphragm seals the pumped liquid completely away from the pump’s mechanical components, which means diaphragm pumps can handle corrosive, abrasive, viscous and shear-sensitive fluids without contamination or mechanical damage.
Pharmaceutical diaphragm pumps are usually constructed in 316 stainless steel or PTFE, with FDA, 3A and EHEDG certifications that meet the strict hygiene and validation standards of pharmaceutical manufacturing. Their gentle, low-shear pumping action protects sensitive formulations, and their clean-in-place compatibility minimises downtime between batches.
AODD pumps are dry-run capable; these pumps can operate without fluid for short periods without immediate damage.
The diaphragm material must be chemically compatible with the fluid being pumped and rated for its temperature. Common materials include PTFE for aggressive chemicals, Santoprene for general-purpose duty, Neoprene for petroleum-based fluids, and EPDM for water-based applications. Use our Diaphragm Selector tool, or call us and we’ll recommend the right material for your fluid.
The pump body itself typically lasts 15–20 years or more with proper maintenance. Diaphragms are the main wear item and last anywhere from six months to several years, depending on the fluid, operating pressure and cycle rate. Valve balls and seats are also periodic replacement items. We stock spare kits for all AODD pump models we supply.
