Qingdao Nuodean Pump Co Ltd — air operated double diaphragm pumps since the DP series
Nuodean technician assembling air operated diaphragm pumps on the production floor
Air Operated Double Diaphragm Pumps

Pumps That Keep Running When The Fluid Fights Back

Abrasive slurry, high solids, aggressive chemicals, shear sensitive product. Nuodean AODD pumps run dry, self prime, deadhead against a closed valve and start again without damage. 29 models from 1 inch to 3 inch.

Rows of finished Nuodean diaphragm pumps on pallets in the factory
DP3X Series

A Stall Free Air Motor Is The Whole Point Of A Diaphragm Pump

The DP3X air end pairs a major air valve with a pilot air valve and dual ceramic dynamic seals. Faster shift signal, no stall out, no lubrication, less pulsation and an anti icing vacuum chamber that keeps the exhaust clear.

Assembled Nuodean AODD pumps lined up on pallets before packing
Drop In Replacement

Same Footprint Same Ports Different Invoice

Nuodean pumps are built to the installation dimensions and footprint of the major AODD brands, so a replacement drops onto the existing base, pipework and air line. Send us the pump you run today and we will match it.

29
Pump models in production
1" to 3"
Port sizes across the range
897 LPM
Maximum flow rate, 3 inch metallic
8.3 bar
Maximum discharge pressure
What We Make

What We Build In Qingdao

Nuodean does one thing. We research, build, sell and service air operated double diaphragm pumps, and we have developed several generations of them.

Metallic AODD Pumps

Aluminum, cast iron and 316 stainless steel wetted parts for solvents, oils, paints, adhesives and abrasive slurry.

Non Metallic AODD Pumps

Polypropylene and PVDF fluid ends for acids, alkalis, electroplating baths and other liquids that attack metal.

High Pressure And Specialty

Triple diaphragm pumps with a two to one pressure ratio, dry powder pumps and flap valve pumps for solids to 50 mm.

Spare Parts And Repair Kits

Air section and fluid section kits, diaphragms, balls, seats and complete part lists for every model we ship.

Pump Range

Pumps Buyers Ask For Most Often

Twelve of the twenty nine models we build. Every product page carries the transcribed data sheet, the material options and the drawings.

Front view of a black industrial double diaphragm pump with red caps and green accents.
DP3X Series

2 Inch Aluminum Air Operated Double Diaphragm Pump

651 LPM and 8.3 bar from a 29.6 kg aluminum body. The volume workhorse of the DP3X range.

View Specifications →
A silver metallic industrial double diaphragm pump with red caps and a central black manifold.
DP3X Series

2 Inch Stainless Steel Air Operated Double Diaphragm Pump

651 LPM and 8.3 bar from a 56.9 kg stainless steel body. The corrosion resistant workhorse of the DP3X range.

View Specifications →
Front view of a black industrial double diaphragm pump with red ports on a white background
DP3X Series

2 Inch Non Metallic Air Operated Double Diaphragm Pump

548.8 LPM from a 28.1 kg non metallic body. The chemical duty workhorse of the DP3X range.

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Front view of a symmetrical industrial double diaphragm pump with a black manifold and a central gold filter.
DP3X Series

2 Inch Cast Iron Air Operated Double Diaphragm Pump

651 LPM and 8.3 bar from a 56.4 kg cast iron body. The heavy duty workhorse of the DP3X range.

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Front view of an industrial double diaphragm pump with black manifold and silver chambers.
DP3X Series

1-1/2 Inch Aluminum Air Operated Double Diaphragm Pump

340.7 LPM and 8.3 bar from a 23.4 kg aluminum body. The mid-range volume pump in the DP3X series.

View Specifications →
Front view of a stainless steel industrial double diaphragm pump with red caps on a white background.
DP3X Series

1-1/2 Inch Stainless Steel Air Operated Double Diaphragm Pump

340.7 LPM and 8.3 bar from a 38.3 kg stainless steel body. The durable workhorse of the DP3X range.

View Specifications →
Front view of a pneumatic double diaphragm pump with black manifolds and silver diaphragm chambers
DP3X Series

3 Inch Aluminum Air Operated Double Diaphragm Pump

897 LPM and 8.3 bar from a 49.8 kg aluminum body. The largest volume pump in the DP3X range.

View Specifications →
A black industrial diaphragm pump with green accents and a red port cover on a white background.
DP3X Series

3 Inch Cast Iron Air Operated Double Diaphragm Pump

897 LPM and 8.3 bar from a 96.7 kg cast iron body. The heavy duty volume pump in the DP3X range.

View Specifications →
Front view of a black industrial double diaphragm pump with red ports on a white background
DP3X Series

1 Inch Aluminum Air Operated Double Diaphragm Pump

133 LPM and 8.3 bar from an 8.6 kg aluminum body. The compact workhorse of the DP3X range.

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Front view of a gray industrial double diaphragm pump with flanged ports and a black center block.
DP3X Series

1 Inch Non Metallic Air Operated Double Diaphragm Pump

177.9 LPM and 8.3 bar from a 9.2 kg non metallic body. The entry point for corrosion resistance in the DP3X range.

View Specifications →
Front view of a stainless steel double diaphragm pump with green gaskets and a red center button.
Specialty

2 Inch High Pressure Triple Diaphragm Pump

172 GPM and up to 200 psi fluid pressure from a 90 kg triple diaphragm design. The high pressure workhorse of the Specialty series.

View Specifications →
Black double diaphragm pump with green O-rings and flanged connections on a white background
Specialty

Heavy Duty Flap Valve Diaphragm Pump

647 LPM and 8.3 bar from a 130 kg pump built for 50 mm solids. The only AODD in the range with a horizontal fluid path.

View Specifications →
Browse All 29 Pumps Download Datasheets
Pump Series

Five Series So The Duty Decides The Pump

The DP3X range is the current generation. The WA range and ZG range exist because different plants and different budgets need different pumps.

Who We Serve

Plants That Run Nuodean Pumps

The applications listed in our catalogues are the ordinary hard ones. Waste water, acid, alkali, solvent, paint, cutting fluid, quenching oil, electroplating liquid, condiments and shear sensitive product.

What We Solve

What Actually Goes Wrong With A Transfer Pump

Most enquiries we answer are not about flow rate. They are about a pump that stopped, iced up, tore a diaphragm or cannot be sourced fast enough.

The pump stalls at the end of the stroke

A pilot air valve gives the main valve a positive, fast shift signal, so the pump trips over instead of hanging at mid stroke and needing an operator to tap it.

The air end ices up and slows down

The DP3X air section uses a built in vacuum chamber that lowers discharge air pressure and temperature drop, which is where icing and the noise come from.

The exhaust oil mist contaminates the room

The air distribution system is self lubricating and lube free, so there is no oiler on the air line and no oil carried out with the exhaust.

Solids destroy the check valves

Ball and seat materials run from nitrile to hard stainless steel, and the flap valve pump swallows suspended solids up to 50 mm without jamming.

The chemical eats the wetted parts

The same pump body is offered in aluminum, cast iron, 316 stainless steel, polypropylene and PVDF, with PTFE, Viton, EPDM, Santoprene, Hytrel, neoprene or nitrile elastomers.

Nobody stocks the replacement

Nuodean pumps keep the installation dimensions and footprint of other brands, so the swap needs no new base, no new pipe spool and no new air line.

Why Nuodean

Why Buyers Come Back To Nuodean

Not slogans. The four things that are actually written on our certificates, our drawings and our data sheets.

  1. Our Own Patented Air Motor

    The air motor is the heart of an AODD pump. Ours is covered by Chinese utility model patents and the certificates are printed in our catalogues. Excellent shift behaviour, no stall, no lubrication and long service life.

  2. Data Sheets For Every Model

    Flow, discharge pressure, solids size, suction lift, weight and sound level are published per model, with a full model code so you can specify seat, ball, diaphragm and hardware material yourself.

  3. Drawings And Part Lists Are Public

    Fluid section and air section drawings with numbered part lists are downloadable, so a maintenance team can identify a worn part before the pump comes apart.

  4. Five Generations Of Product

    The company has developed multiple generations of pumps. DP3X inherits the earlier DP designs and improves the air distribution system, and the WA and ZG series stay available for plants standardized on them.

See It Run

Nuodean Pumps On Video

Two of our own animations. The first shows the air distribution system driving the center section, the second follows the stroke cycle that the working principle guide describes in words.

Nuodean diaphragm pumps running on test, showing the center section in operation.
Working principle animation. Compressed air in red, atmospheric pressure in blue, as the diaphragm moves from right to left and back.
Solutions

How We Work With Buyers

Four routes through our range, depending on whether you are specifying a new duty, replacing another brand, fighting an abrasive fluid or keeping a fleet running.

Knowledge Center

Engineering Guides Not Blog Posts

How the air motor shifts, how to size a pump, which diaphragm material survives your fluid and what to check when the pump slows down.

Read All Guides
Answers

Questions Buyers Ask Before Ordering

What is the minimum order quantity?

There is no fixed minimum. We ship single pumps for trials and replacement duty as well as production batches, and we quote them differently, so tell us which you need.

Can I buy a pump in a material combination that is not on the data sheet?

The model code sets the center body, fluid caps and manifold, seat, ball check, diaphragm, fluid connection and hardware separately. If a combination is possible in the code we can normally build it, so send us the code you want and we will confirm.

Do your pumps fit where another brand sits now?

The DP3X pumps are designed so that installation dimensions and footprint are compatible with other brands. Send a photo of the nameplate and the pipework and we will confirm the match before you order.

What air supply do the pumps need?

Air inlet connections run from 1/4 inch BSPT on the 1 inch pumps to 3/4 inch BSPT on the 2 inch and 3 inch pumps, with NPT available on request. Maximum operating air pressure is 8.3 bar on the standard models.

How are the pumps packed and shipped?

Pumps ship crated with the data sheet and the fluid and air section part lists. We handle export documents from Qingdao, and we quote sea or air freight against your port or your forwarder.

Do you supply spare parts for pumps bought years ago?

Yes. Air section and fluid section repair kits are catalogued by model code, and the drawings are on the download page. Send the code from the pump nameplate and we will match the kit.

Send Us The Fluid And The Duty

Tell us the liquid, the flow you need, the discharge head and the air pressure you have available. We will come back with the model code, the material build and a price.

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