Wilden Air-Operated Double Diaphragm Pump – AODD Pump for Corrosive & Particle-Laden Fluids

A WILDEN air-operated double diaphragm (AODD) pump moves liquid with two flexible diaphragms driven by compressed air. There is no motor, no rotating shaft and no shaft seal, which is why these pumps are used for corrosive chemicals and liquids that carry particles.

How it works

Compressed air pushes one diaphragm while the other is pulled back by a connecting rod. Each stroke draws liquid in through one ball check valve and pushes it out through another. Flow is controlled simply by the air supply, and the pump stops on its own if the discharge is closed.

What the range covers

Wilden lists 2,476 pump builds. They span 1/4 inch to 4 inch ports and five body materials: aluminum, stainless steel, cast iron, polypropylene and PVDF.

Port size	Example models	Max flow (example build)
1/4″	P.025, PS25	5 to 5.7 gpm (19 to 22 L/min)
1/2″	P1, XPS1, P100	14.8 to 15.9 gpm (56 to 60 L/min)
1″	P2, P220, XPS220, P200	44 to 58 gpm (167 to 220 L/min)
1-1/2″	P4, XPS4, XPS420, P400	76 to 132 gpm (288 to 500 L/min)
2″	P8, XPS8, T8, P800	141 to 190 gpm (534 to 719 L/min)
3″	T15, XPS1520, P1500	195 to 271 gpm (738 to 1026 L/min)
4″	T20, XPS20, PS20	274 to 277 gpm (1037 to 1049 L/min)

Corrosive and particle-laden liquids

• For acids and alkalis, polypropylene, PVDF or stainless steel bodies with PTFE diaphragms are the usual starting point
• Solids pass through the ball valves, so the limit depends on the model: 0.02 inch (0.5 mm) on the P.025 and up to 0.25 inch (6.4 mm) on the larger bolted pumps Wilden lists
• Most metal models are rated for air pressure up to 125 psi (8.6 bar); some plastic models are lower, for example 100 psi (6.9 bar) on the P1500

Browse every build by part number in our WILDEN lookup.