Understanding AODD Pumps: How Air-Operated Diaphragm Pumps Work

If you work with industrial fluid transfer systems, understanding AODD pumps (Air-Operated Double Diaphragm pumps) is essential. These pumps are among the most versatile and reliable options across manufacturing, chemical processing, food production, oil and gas, and many more industries.

This guide explains everything you need to know — what AODD pumps are, how they work, their advantages, limitations, applications, and essential best practices. We’ll also include helpful infographics along the way.

To begin understanding AODD pumps, it’s important to know they operate using compressed air rather than electricity. This makes them:

• Intrinsically safe

• ATEX-friendly (explosion-proof)

• Portable

• Easy to maintain

AODD pumps typically consist of:

• Two diaphragms

• Air valve (the “heart” of the pump)

• Connecting rod

• Inlet & outlet check valves

ARO AODD Pumps

Understanding AODD pumps begins with their operating cycle:

1. Compressed air pushes diaphragm A outward

2. This draws fluid into chamber B

3. Air valve shifts

4. Diaphragm B is pushed, discharging fluid

5. Cycle repeats rapidly (up to hundreds of cycles per minute)

This creates a pulsating but efficient flow, ideal for thick, sensitive, or particulate-laden fluids.

AODD pumps are popular because they can handle a wide range of fluids and environments. Key industries include:

• Chemical Processing (corrosive & hazardous liquids)

• Food & Beverage (sanitary or FDA-approved materials)

• Paints, Inks & Coatings

• Pharmaceuticals & Cosmetics

• Mining & Construction (slurries, abrasive fluids)

• Oil & Gas

• Water & Wastewater (solids handling)

FDA Food Grade

Sanitary Diaphragm Pumps

When understanding AODD pumps, it helps to know their core benefits:

1. Can Run Dry without Damage

Huge advantage over centrifugal pumps.

2. Handle Solids and Slurries

Debris, fibres, and particulates are not a problem.

3. Self-Priming

Often up to several metres.

4. ATEX Safe for Hazardous Areas

Perfect for explosive or volatile atmospheres.

ATEX Directive

5. Gentle on Product

Perfect for shear-sensitive materials.

6. Easy & Low-Cost Maintenance

Diaphragms and check valves can be replaced quickly.

Common issues include:

1. Insufficient Air Supply

Fix: Check air pressure, hose size, and regulators.

2. Diaphragm Wear or Failure

Fix: Replace diaphragm and choose correct material.

3. Debris Blockage

Fix: Install a strainer and clean suction lines.

While understanding AODD pumps, remember limitations:

Air Consumption

They require a stable supply of compressed air.
EPA Compressed Air Efficiency Guidelines

Pulsating Flow

Use dampeners for accuracy.

Pressure Limits

Most AODD pumps max out around 8.6 bar.

Understanding AODD pumps also involves proper care:

Choose the Right Diaphragm Material

• PTFE → chemicals

• Santoprene → general purpose

• Viton → solvents

• EPDM → water-based or food-grade fluids

Maintain Clean, Dry Air

Moisture shortens air valve life.

Check Diaphragms Every 6–12 Months

Performance drops before complete failure.

By fully understanding AODD pumps, you’ll be better equipped to choose the right pump for your application — whether you’re moving chemicals, wastewater, food products, adhesives, slurries, or solvents. Their flexibility, safety, and ease of use make them one of the most widely used pump types worldwide.

👉 Contact the AroPlus team for expert pump advice
👉 Browse ARO diaphragm pumps at AroPlus

FAQS