3 Inch

3 Inch DP3X Air Operated Double Diaphragm Pumps

The 3 inch DP3X pumps are built for heavy-duty transfer where flow and solids handling are the priority. They are not for low air pressure or intermittent use. A consistent, high-volume air supply is required to maintain performance.

Request A Quote See The 3 Models

Models

Three Models For Heavy Duty

Aluminum for light slurry and cost sensitivity, cast iron for abrasion resistance, stainless steel for corrosion and chemical exposure. All share the same air end and performance envelope.

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 →

Silver metallic double diaphragm pump with green gaskets and a red center cap.

DP3X Series

3 Inch Stainless Steel Air Operated Double Diaphragm Pump

897 LPM and 8.3 bar from a 100.79 kg stainless body. The high volume workhorse of the DP3X range.

View Specifications →

Who It Is For

Who Uses These 3 Inch Pumps

Plants that move large volumes of thick liquids, sludges, or abrasive slurries where pump size and throughput are critical.

Waste water treatment plants transferring sludge from clarifiers to dewatering presses
Mining and mineral processing sites pumping tailings or slurry with 9.5 mm solids
Industrial facilities moving abrasive cutting fluid or quenching oil with metal fines
Bulk transfer operations unloading IBCs or tankers with viscous or particulate-laden liquids
Chemical plants handling high-volume batches of shear-sensitive or abrasive materials

Metalworking And Machine Tools Paints Inks And Coatings Chemical Processing Mining And Coal Handling

Problems Solved

Why This Size Needs A Serious Air Supply

The 3 inch pump's performance depends on consistent air pressure and flow. Low air pressure causes underperformance, pulsation, and early wear.

Low air pressure leads to slow stroke cycles and reduced flow, which causes the pump to stall or lose prime
Inconsistent air supply causes erratic pulsation and increases wear on the diaphragms and valves
A weak air line cannot sustain the 8.3 bar discharge pressure, so the pump operates below design capacity
Running the pump at low air pressure reduces the effectiveness of the anti-icing design, increasing the risk of valve freeze-up
The self-lubricating air system relies on sufficient air flow to function. Low flow reduces its effectiveness

Core Advantages

Three Key Features For This Size

Stall-Free Air Distribution

The pilot air valve ensures the major valve shifts quickly and fully. This prevents mid-stroke stalling, which is common in large pumps under low air pressure.

Dual Ceramic Seals

Both the major and pilot air valves have ceramic dynamic seals. This resists wear from abrasive solids and maintains clean, fast valve shifts over time.

Anti-Icing Design

The built-in vacuum chamber reduces discharge air pressure and prevents ice formation on the air end, even in cold environments.

Range Data

Performance At 3 Inch

All three 3 inch models share the same hydraulic performance. Differences are in weight, material and service life.

Port size	3 inch
Maximum flow rate	897 LPM (237 GPM)
Maximum operating pressure	8.3 bar (120 psi)
Suspended solids max diameter	9.5 mm (3/8 inch)
Maximum dry suction lift	5.4 m (17.6 feet)
Body materials	Aluminum, cast iron, 316 stainless steel
Weight	49.8 kg (109.8 lbs) for aluminum, 96.7 kg (213.1 lbs) for cast iron, 100.79 kg (222.2 lbs) for stainless steel

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.

Application Scenarios

Typical 3 Inch Duties

Sludge Transfer To Dewatering Press

The pump handles thick sludge with 9.5 mm solids. It runs dry at the end of each cycle and restarts when the press is stripped.

Bulk Unloading Of IBCs And Tankers

Self priming with a 5.4 m dry lift allows emptying large containers from ground level without additional priming.

High Volume Slurry Transfer

Used in mining and processing to move abrasive slurries over long distances with minimal maintenance.

Recirculation Of Abrasive Fluids

Circulates cutting fluid or quenching oil that carries metal fines, with the pump running dry at the end of each cycle.

Guides For The 3 Inch DP3X Range

Working Principle

How An Air Operated Double Diaphragm Pump Works

Follow one full stroke through the pilot valve, the major air valve and both liquid chambers, and the rest of the pump stops being mysterious.

Buying Guide

How To Size An Air Operated Double Diaphragm Pump

Sizing an air diaphragm pump from the existing pipe size or the headline maximum flow guarantees poor performance. Here is how to select the right displacement and port size from actual duty conditions.

Material Guide

Aluminum Cast Iron Stainless Steel or Polypropylene Pump Body

Compare aluminum, cast iron, stainless steel and non metallic bodies by fluid, duty and weight, not by habit.

Answers

3" DP3X Diaphragm Pumps FAQ

What air supply is needed for a 3 inch DP3X pump?

The pump requires a consistent supply of compressed air at 6 to 8 bar. A 3 inch pump will not perform at full capacity on a low-pressure line. Use a regulator and filter to ensure stable supply.

Can I use the aluminum model in a corrosive environment?

Aluminum is not suitable for acids, alkalis or saltwater. Use the cast iron or stainless steel model if the fluid is corrosive or contains chlorides.

How do I choose between cast iron and stainless steel?

Cast iron resists abrasion better and is lighter. Stainless steel resists corrosion and is suitable for chemicals, food-grade fluids, and high-purity applications.

Are the pumps ATEX certified?

We do not publish an ATEX certificate. The pumps are air driven with no electric motor, which makes them suitable for hazardous areas, but if you need certification for your site, contact us to confirm what documentation is available.

What is the lead time for a 3 inch pump?

The lead time depends on the model code and quantity. All models are built to order. Send the full code and required quantity to get a confirmed delivery date.

Specify A 3 Inch DP3X Pump For Your Bulk Duty

Send the fluid, the required flow, the discharge head, and your available air pressure. We will confirm the best model and send the full code.

Chat On WhatsApp [email protected]?subject=Inquiry%3A%203%22%20DP3X%20Diaphragm%20Pumps All Products