Air Operated Double Diaphragm(AODD) Pump


The air valve directs pressurized air to the back side of diaphragm A. The compressed air is applied directly to the liquid column separated by elastomeric diaphragms. The diaphragm acts as a separation membrane between the compressed air and liquid, balancing the load and removing mechanical stress from the diaphragm. The compressed air moves the diaphragm away from the center block of the pump. The opposite diaphragm is pulled in by the shaft connected to the pressurized diaphragm. Diaphragm B is on its suction stroke; air behind the diaphragm has been forced out to the atmosphere through the exhaust port of the pump.

The movement of diaphragm B toward the center block of the pump creates a vacuum within chamber B. Atmospheric pressure forces fluid into the inlet manifold forcing the inlet valve ball off its seat. Liquid is free to move past the inlet valve ball and fill the liquid chamber (see shaded area).

Air Operated Diaphragm Pump left stroke


When the pressurised diaphragm, diaphragm A, reaches the limit of its discharge stroke, the air valve redirects pressurised air to the back side of diaphragm B. The pressurised air forces diaphragm B away from the center block while pulling diaphragm A to the center block.

Diaphragm B is now on its discharge stroke. Diaphragm B forces the inlet valve ball onto its seat due to the hydraulic forces developed in the liquid chamber and manifold of the pump. These same hydraulic forces lift the discharge valve ball off its seat, while the opposite discharge valve ball is forced onto its seat, forcing fluid to flow through the pump discharge. The movement of diaphragm A toward the center block of the pump creates a vacuum within liquid chamber A. Atmospheric pressure forces fluid into the inlet manifold of the pump. The inlet valve ball is forced off its seat allowing the fluid being pumped to fill the liquid chamber.

Air Operated Double Diaphragm Pump mid stroke


At completion of the stroke, the air valve again redirects air to the back side of diaphragm A, which starts diaphragm B on its exhaust stroke. As the pump reaches its original starting point, each diaphragm has gone through one exhaust and one discharge stroke.

This constitutes one complete pumping cycle. The pump may take several cycles to completely prime depending on the conditions of the application.

Air Operated Double Diaphragm Pump right stroke
DIAPHRAGM PTFE/Rubber PTFE/Rubber PTFE/Rubber PTFE/Rubber PTFE/Rubber
SUCTION & DISCHARGE 12 inch 1 inch 1 12 inch 2 inch 3 inch
AIR INLET 14 inch 12 inch 12 inch 34 inch 1 inch
MAX FLOW 33 LPM 90 LPM 140 LPM 300 LPM 400 LPM
DISCHARGE PRESSURE (Kg/sq. cm) 6 6 6 6 6
HEAD (meter) 30 60 60 60 60
SUCTION LIFT (meter) 1.8 4.8 5.5 5.8 5.8
MAX SOLID SIZE in (mm) 2.5 3.4 5 6.5 10

1. Ability to Run Dry – All air operated double diaphragm pump supplied by Antlia are able to run-dry without damage. This is a very useful feature to have when the pumping application may result in varying & inconsistent suction conditions.

2. Ability to Self-Prime – This means that Antlia diaphragm pump can be used as sump pumps & where positive suction conditions are not available.

3. Ability to Pass Solids – The ball & seat/ check-valve design allows for AODD pump to pass solid particles. This is beneficial in a wide range of applications such as pumping slurries or food products with seeds.

4. Variable Flow-rate & Discharge Pressure – Varying of air supply to the pump will vary the flow rate and/ or pressure that the diaphragm pump produces.

5. Seal-less/ Leak Free Design – No mechanical seal means that the Air pumps are totally contained & leak-free.

6. Ease of Maintenance – Diaphragm pumps are simple, non-technical & require no specialist training for maintenance. There are no special clearances or tools required for pump repairs.

7. Anti-Stalling/ Anti-Freezing Air Motor – The air valve is designed to be anti-stalling & anti-freezing; this assists allowing the AODD pump to be continuously operated.

8. Intrinsically Safe – No electrical power or auxiliary requirements meaning that diaphragm pump is Intrinsically Safe and can be operated in many hazardous situations/ applications like underground coal mines.

9. Submersible Options – Most AODD models can be fully submerged. When using as submersible pump, both the liquid path and external components must be compatible with the material in which the pump will be submersed. Submersed pumps must have a hose attached to air exhaust and the exhaust piped above liquid level.

Chemical & Refineries

AODD Pump can handle all types of chemicals including acids, bases, solvents and alkalis, resins and adhesives, high-density liquids and viscous products even with the presence of solid parts and particles. Moreover, they can also transfer oil skimming, oil sludge, storm water, seawater, drainage water, latex, corrosion inhibitors, fertiliser, pesticides, insecticides and more.

The AODD Pump finds application in pumping of raw materials and derivatives, storm water drainage, unload trucks, sump and tanks drainage, empty the cistern and to be used in waste water treatment, desalination plants, scrubber’s application, distillation plant and filters press.

Air Operated Double Diaphragm Pump application in waste water treatment

Air Operated Double Diaphragm Pump

Waste Water Treatment

In the water treatment industry, diaphragm pumps are used in industrial and municipal wastewater treatment plants. Some fluids that are put into the pumps from wastewater treatment plants are high in viscosity and require pumps that can handle those liquids. Air operated double diaphragm pumps also help to pump polymers, acids, caustics and slurries during the water treatment process that are used to treat water.

Food & Beverages

Air operated double diaphragm pump are used in the food and beverage industry for various food processing application. This pumps can be used for transferring food products like tomato pulp, chocolate, soft drinks, ham pulp, vinegar, pet food, yeast, eggs, vegetable oil, honey, vitamins, glucose syrup, concentrates, decaffeination, wine, fruit pulp, fruit juice, rennet, aromas and more.

Moreover, diaphragm pumps can be used also for pumping chemicals like caustic soda, nitric acid, hydrochloric acid, antioxidants and brine and waste products like animal blood, waste water and sludge. They find application in the food processing, CIP (cleaning in place) plants, and waste water treatment and slaughtering.

Air Operated Double Diaphragm Pump application in foods and beverages industries

Air Operated Double Diaphragm Pump paint manufacturing industries

Paints & Coating

AODD pump are also used in the paint industry considering their ability to move viscous fluids like ink, acrylic, primers and coatings.

Moreover air pumps are capable of transferring solvents for washing systems and waste fluids.

The main applications that we can find in this field are printing machines, inks maker, spray systems and cleaning baths.


In the Pharma field air operated double diaphragm pump is one of the main systems for pumping fluids considering that a large part of them contain particles and have high viscosity.

For this reason, AODD pump can handle chemicals, proteins, enzymes, vitamins, vegetable extracts, flavours, ointments, alcohols, blood plasma, additives, disinfectants, waste solvents, waste fluids and more.

The main applications are filtering aids, ultrafiltration, aseptic transfer, tablet coating, distillation plant, reactors for the production and waste water treatment.

AODD pump application in pharma industries

AODD pump application in steel manufacturing industry

Steelworks & Foundries

In the Steel Working Industry is easy to find applications like flushing of cores, mold release, rolling mills and galvanizing which are using positive displacement pumps

Pneumatically operated pumps can transfer the following fluids: amine, metal sludge, dust scrubbing slurry, drainage water, and corrosion inhibitors, grinding and cutting oils

Cosmetics & Cleaning

Air Operated Double Diaphragm pump are also used in the cosmetic and cleaning industry to pumping a lot of fluids starting from the raw materials and the end-products up to chemicals and additives.

Typical fluids used in the cosmetic and cleaning field are: lotions, surfactants, fabric softener, creams, shampoos, emulsions, hair permanents, soaps, foaming agent, disinfectants, detergents, gels and others more.

AODD pump application in cosmetic products manufacturing industry

AODD pump application in semi conductor and electronics industry

Semiconductor & Electronics

Solvents, ultra-pure liquids, sulphuric acid, nitric acid, waste liquids, anodic sludge, stabilisers, electrolytes are the main fluids which needs to be taken care of in the Semiconductor & Electronics Industry.

The common applications are: ultrasonic washing and electroplating baths.

Textile & Tanning

In the Textile and Tanning industry, the AODD pump are used for dosing the chemicals like ammonia, formic acid and solvents but also for pigments, ink and paint.

The main applications of this field are: colouring, processing fluids, dosing of chemicals, ink maker, waste water treatment and unload truck.

AODD pump application in textile industry

AODD pump application in galvanic industry


The Diaphragm pumps find an extensive use considering their ability to moving chemical aggressive fluids including the waste products which contains metallic solid particles.

The typical applications of this field are: surface treatment, electrostatic plating, galvanic baths, polishing, filtering system and waste fluids.

Pulp & Paper

The Pulp & Paper is another of the main field where the Air Operated Double Diaphragm Pump found applications.

The common liquids that the AODD Pump can transfer are additives, ink and paint, and of course the chemicals.

AODD pump application in pulp industry

AODD pump application in construction and mining industry

Constructions & Mining

The construction industry’s needs for heavy duty performance, abrasion resistance and solids-handling capabilities make AODD pump a perfect fit. These pumps help to increase productivity by remaining reliable even while handling these tough jobs.

Energy & Power Plant

The main applications of this field are chemical transferring, biogas and biofuel plants, battery manufacturer, denitrification, fuel cells, and waste water treatment.

AODD pump application in energy and power plant

AODD pump application in automobile industry


Diaphragm Pumps are also used for moving oil emulsion, coolant, hydraulic fluid, sulphuric acid, varnish and primer, additives, glycol, fuelling and waste oil.

Main applications: degreasing baths, tank and car washing, oil/water separators and more.

Air Operated Double Diaphragm Pump Graph 1
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