Air Operated Diaphragm Pumps

Air Operated Diaphragm Pumps

Excel Fluid Group offers Verderair diaphragm pumps as an excellent solution for applications that require more than fluid transfer. Also liquids containing solids, viscous, or sticky media will be handled without problems.

The Verderair diaphragm pump series offer a wide range of wetted materials, varying from metallic (aluminum, cast iron and stainless steel) to non-metallic (Acetal, Polypropylene, Kynar, conductive Polypropylene, Polyethylene, PTFE). Verderair air operated diaphragm pumps are easily installed and easy to maintain. They are excellent backup and emergency pumps, with capacities up to 320 GPM, at up to 230 PSI. The complete range of Verderair, Verderair Pure and Verderair HI-CLEAN air operated double diaphragm pumps are the most efficient diaphragm pumps on the market.

Verderair double diaphragm pumps have quick-acting air valves. The result is an increased productivity, reduced operational cost and improved working environment. This makes the Verderair range the most efficient double diaphragm pumps!

Increased Productivity

Higher Flow Rate, Less Maintenance

Low “pressure drop” when the liquid passes the pump chamber. Smoother flow, increased efficiency pumping the liquid. The diaphragms have a special profile which is designed for an extremely long working life.

Reduced Operational Cost

Lower Air Consumption

The quick-acting air valves change directions very fast. No compressed air is entering the air chamber when the stroke is already completed. The used compressed air is scavenged from the pump with almost no restrictions. The compressed air is only used to move the liquid!

Improved Working Environment

Less Noise

By using all of the compressed air, the pump makes less noise and the risk of freezing the exhaust is reduced.

50 Years of Experience

More than 600,000 Diaphragm Pumps Sold

With more than 50 years of experience in double diaphragm pump technology, and having sold more than 600,000 pumps all over the world, Verder continuously improves its technology to increase the efficiency of the Verderair pumps without using ancillary equipment. All other brands need ancillary equipment to enlarge the efficiency of the pump; needing no such equipment to achieve the best performance makes a Verderair the most efficient diaphragm pump.

Special Features of Verderair Pure

  • Solid design for perfect pressure holding & limited vibrations
  • No metal wetted or external parts
  • Possible to build pulsation dampener on top as integrated unit
  • Access to valve seat and balls without disassembling

Some of the Verderair’s Features

  • Quick-acting air valve
  • Easy to install
  • Portable for multi-location use
  • Easy to maintain
  • Easy to operate
  • Free of air lubrication
  • Can run dry without damage (no run-dry protection needed)
  • Can run against closed valves
  • Non-stalling air valves
  • Dry self priming
  • No dynamic or pressure loaded seals

Special Features of Verderair VA

  • Bolted chambers for safe operation and easy maintenance
  • Rugged, cast feed mounting holes for limited vibrations
  • Plastic versions with inserts in pump chambers for holding optimum pressure

Materials to Choose From to Meet Your Most Severe Process

To meet your most severe process conditions, yet still having a trouble-free operation, Verderair pumps have nine different material options for the valve seat, diaphragm & balls. The combination of these high quality materials together with the choice of different pump materials give the optimum pump selection.

Acetal – Wide range of solvent resistant and withstands extreme fatigue. Good level of abrasion resistance. Electrical conductive. (Atex!).
Santoprene – Good resistance to abrasive and chemical fluids. Santoprene is compatible with some solvents (e.g. Acetone, MEK), caustic solutions, dilute acids and alcohols.
Teflon (PTFE) – Most compatible material for chemical applications, extremely resistant to corrosion and high temperatures, very low friction coefficient, non-adhesive.
Thermoplastic polyester – (Hytrel) Good performance properties at lower temperatures and good resistance to abrasive fluids. Thermoplastic polyester is often a substitute for Buna-N.
Fluorelastomers – (Viton) High heat resistance. Good resistance to aggressive chemicals including acids and some solvents. (e.g. xylene and mineral spirits). Good resistance to steam as well as animal, vegetable and petroleum oils. Resists unleaded fuels.
Geolast – Good abrasion resistance. Approximately same chemical compatibility as Buna-N.
Polychloroprene – (Neoprene) Good chemical resistance, good performance with oils and many chemicals, good temperature resistance, outstanding physical toughness, outstanding resistance to damage caused by flexing and twisting. Resistance to abrasion is approximately 30% higher than Buna.
EPDM – Good water and chemical resistance. Not for use with oils, greases and most solvents.
BUNA – Good for petroleum-based fluids, water, oils, hydrocarbons and mild chemicals (e.g. mineral spirits).

*Note: Not all combinations are available. Please contact Excel Fluid Group for more information.

The Heart of Your Pump

The air valve

Verderair has proven to be the most efficient double diaphragm pump on the market, mainly because of the engineered designs of the air valves of both series. The Verderair Pure pump is especially designed for working in severe environments. The air valve of this series is mounted in the inner of the pump. Therefore the pump efficiency is not influenced by atmospheric circumstances.

The Verderair VA series are equipped with an air valve that has a modular cup and plate design. This air valve design is re-engineered based upon the existing model used successfully in Verderair pumps for many years.

Verderair Pure & Solid

The Verderair Pure double diaphragm pump is a new, robust, high-end series of double diaphragm pumps, produced from one-piece solid material. The Verderair Pure is designed for heavy-duty operation, also for harsh liquids and severe process conditions, such as operating in power plants and refineries.

The Verderair Pure has all the benefits of a Verderair double diaphragm pump such as increased productivity through a higher flow rate and reduced operational cost because of lower air consumption. Thanks to the efficient operation there is less maintenance, and an improved working environment is created because the pump makes less noise. The Verderair Pure is available in 4 wetted part materials; each pump being made from one solid piece of the purest and finest PTFE or PE.


  • Chemicals transfer
  • Pharmaceutical industry
  • Solar power industry
  • Electronics-plating (Galvanics)
  • Refineries


Polyethylene (PE)
Extremely abrasion resistant. Upto 7 times better then Polypropylene. Chemical resistance is comparable to Polypropylene.

Teflon (PTFE)
Widest chemical compatibility, extreme corrosion resistance, very low frictional coefficient, non-adhesive, high heat resistance.

Conductive polyethylene
Similar properties to polypropylene but conductive for Atex applications.

Conductive teflon
Similar to PTFE, but electrically conductive (Atex!)

Verderair Non-Metallic Series

Verderair non-metallic double diaphragm pumps are excellent pumps for use in a wide range of applications across many industries. Depending on your wishes, fluid and process specifications, the best solution is selected.

Verderair VA offers four non-metallic materials to choose from. Conductive Polypropylene and Acetal can be used in Atex rated zones. PVDF is the best choice for even the most chemically aggressive media.


  • Ink & paper
  • Preparation of CIP solutions
  • Surface Finishing
  • Car wash chemicals
  • Water based paints


Wide chemical compatibility. General purpose. Limited temperature resistant.

PVDF (Kynar)
Conductive Polypropylene and Acetal can be used in Atex rated zones. PVDF is the best choice for even the most chemically aggressive media.

Conductive polypropylene
Similar to standard Polypropylene but elecrically conductive (Atex!)

Compatible with many solvent applications and can withstand extreme fatigue. Good resistance to abrasive media and is conductive for Atex applications.

Verderair Metallic Series

If your process fluid is abrasive, a metallic double diaphragm pump will be an excellent choice. VA metallic diaphragm pumps are offered in Aluminium, Cast Iron and SS316. A Verderair can pump just about anything!


  • Slaughterhouse waste
  • Waste water
  • Chemicals transfer
  • Ceramic slurry
  • Solvent based paints


General purpose. Good for solvent based coatings and inks. Resistant to mild chemicals.

Stainless Steel 316
Resistant to most acids, bases and solvents. Can handle halogenated hydrocarbons. Good resistance to abrasive media.

Cast Iron
Highly abrasion resistant. Often used in paper, waste water industry, and mining.

PDF – Verderair Brochure

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