Description
Air Diaphragm Pump (AODD Pump)
The Air Diaphragm Pump, also known as an Air Operated Double Diaphragm (AODD) Pump, is a versatile, robust, and reliable positive displacement pump powered by compressed air.
With no electric motor or rotating parts, it excels at handling abrasive, viscous, corrosive, and shear-sensitive fluids while offering dry-run capability and explosion-proof operation.
Key Features & Benefits
| Feature |
Benefit |
| Self-Priming & Dry-Run Capable |
Can run dry indefinitely without damage and achieve suction lifts up to 8 meters |
| Explosion-Proof Design |
Powered by compressed air – ideal for hazardous and ATEX environments |
| Handles Viscous & Abrasive Fluids |
Excellent for slurries, sludges, chemicals, paints, and shear-sensitive liquids |
| Seal-Less & Leak-Free |
Minimal leakage risk – only stationary seals between wetted parts |
| Variable Flow Control |
Flow rate easily adjusted by regulating air pressure or discharge valve |
| Low Maintenance |
Simple design with few moving parts – easy to service and repair |
Technical Specifications
| Parameter |
Specification |
| Power Source |
Compressed Air (typically 2–8 bar / 30–125 PSI) |
| Flow Rate Range |
From 5 L/min up to 900+ L/min depending on model size |
| Maximum Discharge Pressure |
Up to 8.6 bar (125 PSI) – high-pressure models available |
| Materials of Construction |
Aluminum, Stainless Steel 316, Polypropylene, PVDF, Cast Iron |
| Diaphragm Materials |
PTFE, EPDM, Buna-N (Nitrile), Santoprene, Viton, Neoprene |
| Viscosity Handling |
Up to 90,000 cSt (very high viscosity fluids and slurries) |
✦ Reliable, Versatile, and Safe – The Workhorse of Industrial Fluid Transfer ✦
Ideal for hazardous, abrasive, viscous, and corrosive applications where electric pumps are unsuitable.
Installation Procedures
⚠️ SAFETY FIRST
Ensure the system is fully depressurized and isolated before installation. Wear appropriate PPE. Installation must be carried out by qualified personnel.
Tools & Materials Required
| Adjustable Wrenches & Pipe Wrenches |
For tightening connections |
| PTFE Tape or Thread Sealant |
For threaded connections |
| Level & Measuring Tape |
To ensure proper alignment |
| Flexible Hoses or Expansion Joints |
Recommended to reduce vibration |
| Air Filter-Regulator-Lubricator (FRL) |
For clean and regulated air supply |
Step-by-Step Installation Procedure
| Step |
Procedure |
Important Notes |
| 1 |
Choose a stable, level mounting location with easy access for maintenance and sufficient clearance around the pump. |
Allow space for diaphragm replacement and air connections. |
| 2 |
Install the pump using flexible hoses or expansion joints on both suction and discharge sides to minimize vibration transmission. |
Rigid piping can damage the pump over time. |
| 3 |
Connect the suction and discharge lines. Ensure the inlet (suction) is at the bottom and outlet (discharge) is at the top for self-priming capability. |
Follow the arrow markings on the pump body. |
| 4 |
Install an air filter-regulator-lubricator (FRL) unit on the air supply line and connect clean, dry compressed air (2–8 bar). |
Clean air is essential for long pump life. |
| 5 |
Tighten all connections securely. Use PTFE tape on threaded fittings but avoid over-tightening. |
Check for leaks after pressurizing. |
| 6 |
Slowly introduce air pressure and test the pump at low pressure first. Gradually increase to operating pressure while monitoring for leaks or abnormal noise. |
Never exceed recommended air pressure. |
| 7 |
Verify proper operation: the pump should self-prime and run smoothly without excessive vibration. |
Record initial performance data for future reference. |
✦ Proper installation ensures optimal performance, long service life, and safe operation of your Air Diaphragm Pump ✦
Maintenance Procedures
⚠️ SAFETY FIRST
Always depressurize and isolate the pump before performing any maintenance. Lockout/Tagout procedures must be followed. Wear appropriate PPE.
Tools & Materials Required
| Diaphragm & Valve Replacement Kit |
For scheduled maintenance |
| Adjustable Wrenches & Screwdrivers |
General disassembly |
| Clean Rags & Non-Metallic Scraper |
Cleaning pump components |
| Air Filter-Regulator-Lubricator |
For air supply maintenance |
Step-by-Step Maintenance Procedure
| Step |
Procedure |
Important Notes |
| 1 |
Depressurize the entire system and isolate the pump. Drain all fluid from suction and discharge lines. |
Lockout/Tagout must be applied. |
| 2 |
Remove the air supply line and disconnect suction & discharge hoses. |
Mark connections for correct reassembly. |
| 3 |
Disassemble the pump by removing the center body bolts. Carefully separate the air chamber from the fluid chambers. |
Keep all parts organized. |
| 4 |
Inspect and replace diaphragms, valve balls, and valve seats if worn or damaged. |
Always use genuine spare parts. |
| 5 |
Clean all internal components thoroughly. Remove any sludge, debris, or dried fluid. |
Use non-metallic tools to avoid damage. |
| 6 |
Reassemble the pump in reverse order. Tighten bolts in a criss-cross pattern to recommended torque. |
Do not overtighten. |
| 7 |
Reconnect air supply and piping. Slowly pressurize and test for leaks and proper operation. |
Monitor for unusual noise or vibration. |
✦ Regular maintenance ensures reliable performance and extends the service life of your Air Diaphragm Pump ✦
Q&A
| Question |
Answer |
| What is an Air Diaphragm Pump (AODD Pump)? |
An Air Diaphragm Pump is a positive displacement pump powered by compressed air. It uses two flexible diaphragms and air valves to move fluid without an electric motor or rotating parts. |
| Can the pump run dry without damage? |
Yes. Air Diaphragm Pumps are designed to run dry indefinitely without damage, making them ideal for applications where fluid supply may be intermittent. |
| Is it safe to use in hazardous or explosive environments? |
Yes. Since it is powered by compressed air and has no electrical components, it is intrinsically safe and suitable for ATEX and hazardous areas. |
| What types of fluids can it handle? |
It can handle viscous, abrasive, corrosive, shear-sensitive, and even solids-laden fluids such as chemicals, paints, slurries, oils, acids, and food products. |
| How do I control the flow rate? |
Flow rate is easily controlled by adjusting the air inlet pressure or throttling the discharge valve. No VFD or complex controls are needed. |
| Does it require electricity to operate? |
No. It runs entirely on compressed air, making it ideal for remote locations or areas without electrical power. |
| How often should maintenance be performed? |
Typical schedule: Diaphragms and valve balls every 3–6 months (depending on fluid and usage). Full inspection annually or after 10 million cycles. |
| What are the main advantages over electric pumps? |
Self-priming, dry-run capability, explosion-proof, handles solids and viscous fluids better, simpler design with fewer moving parts, and lower maintenance in harsh environments. |
✦ Have more questions? Contact our technical team for application-specific advice. ✦
Advantages / Disadvantages
| Advantages |
Disadvantages |
Self-priming & Dry-run capable
Can run dry indefinitely without damage and self-prime up to 8 meters. |
Requires clean, dry compressed air
Performance depends on consistent air supply quality and pressure. |
Explosion-proof & Safe
Air-powered design makes it ideal for hazardous and ATEX zones. |
Higher operating cost
Compressed air is more expensive than electricity in many facilities. |
Handles viscous, abrasive & corrosive fluids
Excellent for slurries, chemicals, paints, and solids-laden liquids. |
Pulsating flow
Flow is not as smooth as centrifugal or rotary pumps. |
Simple design & Easy maintenance
Fewer moving parts and easy to service on-site. |
Noise and vibration
Can be louder than electric pumps without proper mounting. |
No electricity required
Can operate in remote locations or power-outage situations. |
Limited maximum pressure
Typically limited to 8–8.6 bar (116–125 PSI). |
Variable flow control
Easy to adjust flow by changing air pressure. |
Air consumption increases with flow
Higher flow rates consume significantly more compressed air. |
✦ The advantages in safety, versatility, and reliability make Air Diaphragm Pumps the preferred choice for many challenging applications ✦
Applications
| Industry / Application |
Typical Fluids Handled |
Key Benefits |
| Chemical Processing |
Acids, solvents, alkalis, polymers, and corrosive chemicals |
Corrosion-resistant materials and leak-free operation |
| Paint & Coatings |
Paints, inks, varnishes, resins, and solvents |
Handles viscous and shear-sensitive fluids without damage |
| Food & Beverage |
Syrups, juices, sauces, dairy products, and edible oils |
Sanitary design with food-grade materials available |
| Mining & Construction |
Slurries, wastewater, cement, and abrasive fluids |
Excellent solids handling and abrasion resistance |
| Pharmaceutical & Cosmetics |
Creams, lotions, gels, and high-purity liquids |
Gentle pumping with minimal shear |
| Oil & Gas / Petrochemical |
Oils, fuels, lubricants, and sludge |
Explosion-proof and safe for hazardous areas |
| Water & Wastewater Treatment |
Wastewater, sludge, chemicals, and filter press feed |
Handles solids and runs dry safely |
✦ Extremely versatile – the go-to pump for difficult fluids in hazardous and demanding environments ✦
