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

Industrial stainless steel pneumatic double diaphragm pump with red caps and green seals

Stainless steel double diaphragm pump with green gaskets and red port caps

Stainless steel double diaphragm pump sitting outdoors on a cobblestone surface

Specialty Pumps

2 Inch High Pressure Triple Diaphragm Pump

The DP32-50 is a 2 inch triple diaphragm pump designed for applications where system pressure exceeds the 120 psi limit of standard AODD pumps. It delivers up to 200 psi fluid pressure with only 100 psi air supply, using a 2:1 discharge ratio that doubles the fluid output per cycle. The pump maintains the same 172 GPM (651 LPM) flow rate as the equivalent two inch single diaphragm pump, but with significantly higher pressure capability. It lifts 8.3 m dry and passes solids up to 6.4 mm, making it suitable for high-pressure transfer, spraying, and long-line pumping where a standard AODD cannot deliver.

Maximum flow rate	172GPM(651LPM)
Maximum operating pressure	100psi(6.9bar)
Suspended solids max diameter	1/4"(6.4mm)
Fluid inlet	2"BSPT Or 2"NPT
Fluid outlet	2"BSPT Or 2"NPT

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Paints Inks And Coatings Chemical Processing

Key Benefits

What The 2:1 Ratio High Pressure Build Delivers

The triple diaphragm design is not about more flow. It is about pressure. The 2:1 ratio makes the difference.

Double The Fluid Pressure With Half The Air

The 2:1 discharge ratio means air pressure is applied to a larger diaphragm area than the fluid side. This allows 100 psi air to generate up to 200 psi fluid pressure, which is ideal for long pipelines, high resistance systems, and spray applications.

Same Flow, Much Higher Pressure

It matches the 172 GPM flow of the standard 2 inch DP31-50 pump but delivers double the fluid pressure. No need to upsize the pump just to get more pressure.

High Pressure Without A Motor

No electric motor, no starter, no VFD, no earthing, no area classification. It runs on 3/4 inch air and delivers high pressure safely in hazardous zones.

No Stalling At The End Of Stroke

The pilot air valve and mechanical actuator pin ensure fast, positive shift of the major air valve. The pump runs smoothly even under high pressure and dead head conditions.

Lube Free Air System

No lubricator is fitted to the air inlet. The air distribution system is self lubricating, so there is no oil mist in the exhaust and no maintenance task to check oil levels.

Built For High Pressure Duty

The design is not a modified standard pump. It is engineered for high pressure with reinforced diaphragms, stronger seals, and a rigid frame to handle the stress.

Who It Is For

Who Buys This Pump

This pump is not for general transfer. It is for systems that need pressure beyond what a standard AODD can deliver.

Chemical plants dosing high pressure into reaction vessels or long pipelines
Pharmaceutical and food processing lines requiring high pressure for cleaning in place (CIP) or spray application
Surface preparation shops using high pressure for rinsing, degreasing or coating
Manufacturers of industrial equipment needing a reliable high pressure pump inside a skid or machine
Plants replacing a standard AODD pump that cannot overcome system resistance or deliver enough pressure

Problems It Solves

Problems This Pump Is Bought To Fix

Every enquiry for this model starts with a system that fails under pressure.

A standard AODD pump cannot push fluid through a long line or high resistance system, while this pump delivers up to 200 psi at the fluid outlet.
A centrifugal pump loses pressure when the tank runs low, but this pump maintains pressure even at low flow and can be run dry.
A single diaphragm pump stalls under high back pressure, but the triple design handles dead head and high pressure without stopping.
An electric pump brings area classification and safety paperwork, while this pump runs on air and avoids the issue.
A standard 2 inch AODD cannot deliver more than 120 psi, but this pump reaches 200 psi with the same 100 psi air supply.

Application Scenarios

Where It Ends Up In A Plant

01

High Pressure Transfer And Spraying

Used in cleaning systems, coating lines, and rinsing operations where fluid must be delivered at high pressure through nozzles or spray bars.

02

Long Line Pumping

Moves fluid through pipelines over 100 meters long with minimal pressure drop, where a standard AODD would fail to deliver.

03

CIP And Cleaning Systems

Delivers high pressure cleaning fluid to tanks, reactors and process lines without requiring an electric pump.

04

Reactor And Batch Dosing

Pushes fluids into high pressure reactors or batch mixers where pressure is part of the process control.

Technical Features

How The Triple Diaphragm System Works

The 2:1 ratio is not a marketing term. It is a mechanical design that doubles the fluid pressure.

2:1 Discharge Ratio
The air diaphragm area is twice the fluid diaphragm area. When air pressure is applied, the force on the fluid side is doubled, allowing 100 psi air to generate up to 200 psi fluid pressure.
Triple Diaphragm Configuration
Two air diaphragms and one fluid diaphragm work in sequence. The air side has two diaphragms to increase the force applied to the fluid side.
Pilot Air Valve For Positive Shift
The pilot valve is shifted mechanically by the actuator pin and pneumatically by the air supply. This ensures fast, clean switching between cycles.
Lube Free Air Distribution
No oiler is fitted. The system is self lubricating, so there is no oil mist in the exhaust and no maintenance task to refill oil.
Reinforced Frame And Mounting
The frame is designed to handle the higher stress from the 2:1 ratio. It prevents distortion under high pressure and maintains alignment.
Interchangeable Connection Options
Fluid inlets and outlets are available in 2 inch BSPT or 2 inch NPT. Air inlet is 3/4 inch BSPT, with 3/4 inch NPT available on request.

Specifications

Published Performance

Transcribed from the Nuodean data sheet published for this pump.

Maximum flow rate	172GPM(651LPM)
Maximum operating pressure	100psi(6.9bar)
Suspended solids max diameter	1/4"(6.4mm)
Fluid inlet	2"BSPT Or 2"NPT
Fluid outlet	2"BSPT Or 2"NPT
Air inlet	3/4"BSPT(3/4"NPT Available On Request)
Maximum dry suction lift	27.2feet(8.3m)
Sound level	70PSI 60 Cycles/Min 90db(A)
Weight	198 lbs(90kg)
Model series code	DP32-50XXXXXXXX

Materials

Material Options

Set in the model code. Ask us if you need a combination the code allows but the sheet does not show.

Wetted materials	Confirmed against your fluid before build

Performance figures are transcribed from the Nuodean data sheet for this pump. Flow is measured at the pump discharge with water at ambient temperature; your duty point depends on air supply pressure, suction conditions, fluid viscosity and discharge head. Ask our engineers to confirm the duty point before you order.

Quality Control

Before It Is Crated

Every pump is run on air before it leaves, so the shift behaviour is checked rather than assumed
Sound level is published at 70 psi and 60 cycles per minute, so you can hold us to it
Diaphragm and seal materials are checked against the ordered model code at assembly
The pump ships with the data sheet and both the air section and fluid section part lists

Customization

What You Can Change

Diaphragm in neoprene, nitrile, Viton, PTFE with Santoprene backing, EPDM, acetal, Hytrel or Santoprene
Ball check in neoprene, nitrile, Viton, PTFE, EPDM, acetal, polyurethane, stainless steel, Hytrel or Santoprene
Seat in aluminum, 316 stainless steel, PVDF, carbon steel, hard stainless steel, Santoprene, Hytrel or nitrile
NPT or BSP threaded fluid connections, stainless steel or carbon steel hardware
3/4 inch NPT air inlet in place of the standard 3/4 inch BSPT, on request

Comparison

Against The Alternatives

Where this pump wins and where you should be buying something else.

Versus the 2 inch standard AODD pump	Same 172 GPM flow, but this pump reaches 200 psi fluid pressure with only 100 psi air. Choose the standard pump if you only need up to 120 psi and want lower weight and cost.
Versus the 1-1/2 inch triple diaphragm pump	The 1-1/2 inch model delivers 90 GPM at 100 psi. This 2 inch model gives 172 GPM at 200 psi. Step up only when higher flow and higher pressure are both needed.
Versus the 3 inch aluminum AODD pump	The 3 inch pump gives 237 GPM and passes 9.5 mm solids, but only up to 120 psi. Choose this triple diaphragm pump when you need 200 psi, even if flow is the same.
Versus the heavy duty flap-valve pump	The flap-valve pump passes 50 mm solids and handles abrasive slurries. Choose the triple diaphragm pump when you need high pressure, not when you need to pass large solids.
Versus the 1 inch triple diaphragm pump	The 1 inch model gives 35 GPM at 100 psi. This 2 inch model gives 172 GPM at 200 psi. The 2 inch is the better choice when both flow and pressure are critical.
Versus a positive displacement electric pump	The electric pump delivers higher pressure and more consistent flow, but requires area classification, earthing, and a control system. This pump avoids all of that.

Use Guide

Getting The Best Out Of It

Five things that decide whether this pump hits 200 psi or stalls under pressure.

Supply Clean, Dry Air
Use a filter and dryer on the air line. A dirty or wet air supply can cause valve sticking and reduce pressure output.
Use The Full 3/4 Inch Air Inlet
A restricted air line limits the air supply and reduces the maximum fluid pressure. Use a short, straight hose with no bends.
Match The Elastomer To The Fluid
Diaphragm and ball material must resist the fluid chemistry and temperature. Wrong material leads to rapid failure and pressure loss.
Avoid Excessive Air Pressure
The maximum air supply is 100 psi. Exceeding this can damage the air end and void the warranty. Use a pressure regulator.
Stock The Repair Kit
Order the DP32-50-Kit, coded for your diaphragm and ball material. It includes all critical wear parts and covers the majority of repairs.

Documents

Documents For This Pump

Straight from Nuodean's own literature: product data sheets, series catalogues.

PDF 2 inch triple diaphragm pump data sheet 1 Product Data Sheets PDF 1.2 MB Download PDF DP11 Series Diaphragm Pump Catalogue Series Catalogues PDF 9.2 MB Download

Need a 2D or 3D CAD model of this pump? CAD on request via WhatsApp.

Answers

2 Inch High Pressure Triple Diaphragm Pump FAQ

What is the maximum fluid pressure this pump can deliver?

Up to 200 psi, as stated in the fluid pressure range. This is achieved with 100 psi air supply, using the 2:1 discharge ratio. The maximum operating pressure of 100 psi is the air side limit.

Can it run dry?

Yes. The pump can be run dry without damage. It is designed to handle dry operation and dead head conditions, which is essential for high pressure systems that may experience blockages.

How loud is it?

90 dB(A) at 70 psi and 60 cycles per minute, as published on the data sheet. Slower cycling and a piped exhaust will reduce the sound level.

What connections does it come with?

Fluid inlets and outlets are 2 inch BSPT or 2 inch NPT. The air inlet is 3/4 inch BSPT, with 3/4 inch NPT available on request.

Will it replace my current high pressure pump?

If your current pump is a standard AODD, yes. If it is an electric pump, it may not be a direct replacement due to different flow and pressure curves. Send us the pump nameplate and system specs and we will confirm.

Which diaphragm should I use?

PTFE with Santoprene backing for aggressive chemicals, Santoprene for general duty, Viton for hot oils and aromatics, nitrile for petroleum products. Tell us the fluid and temperature and we will give you the correct code.

Can I use it for abrasive fluids?

The pump can handle mild abrasives, but for high abrasion duty, the heavy duty flap-valve pump is better suited. The triple diaphragm design is not optimized for wear from grit or sand.