What is a Diaphragm?

What is a Diaphragm

What is a Diaphragm in a Double Diaphragm Pump?

In a double diaphragm pump, the diaphragm is a flexible membrane that moves back and forth to help move fluid through the pump. There are two diaphragms working together inside the pump, powered by compressed air.

As one diaphragm pulls back, it draws fluid into the pump. At the same time, the other diaphragm pushes fluid out. This back-and-forth motion creates a smooth, reliable flow—without the need for seals or motors that can wear out.

Diaphragms are made from durable materials like rubber or Teflon®, depending on the type of fluid being pumped, making them ideal for handling everything from water to harsh chemicals.

Here are our available diaphragm material options:

Product 1
BUNA-N (10–180°F)

Ideal for oil-neutral based solutions.

Product 2
NEOPRENE (0–180°F)

Great for abrasive, non-corrosive fluids.

Product 3
NORDEL™ (-40–212°F)

Handles acids and caustics; not suitable for oils.

Product 4
VITON® (-20–248°F)

Excellent for aggressive fluids, including aromatic and chlorinated hydrocarbons.

Product 5
HYTREL® (0–248°F)

General service diaphragm; non-corrosive, FDA compliant.

Product 6
SANTOPRENE® (-10–180°F)

Resistant to acids, caustics, and abrasives.

Product 7
PTFE (40–212°F)

Designed for highly aggressive fluids like solvents; FDA compliant.

Product 8
ULTIMATE (-70–212°F)

Built for high inlet pressure and abrasive applications; FDA compliant.

Not sure which diaphragm material is right for your application? We're happy to help you choose the best fit based on your fluid, temperature, and operating conditions.