Neoprene Replacement Diaphragms for 2″, 3″ & 4″ Diaphragm Pumps

Neoprene Replacement Diaphragms for 2″, 3″ & 4″ Diaphragm Pumps are a dependable, cost-effective choice for construction dewatering, groundwater control, concrete cutting slurry, and general water transfer applications where chemical exposure is moderate and physical durability is the primary requirement. Ken’s Distributing carries neoprene diaphragms in sizes and configurations compatible with the major diaphragm pump brands used across North America.

If your pump handles clean water, lightly contaminated groundwater, or construction slurry without significant oil or fuel content, neoprene is likely the correct material for your application.

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Compatible Pump Brands

Ken’s Distributing carries neoprene replacement diaphragms for the following pump brands. Click a brand to view neoprene diaphragms specific to that pump.

CH&E Replacement Diaphragm

Magnum Replacement Diaphragm

AMT Replacement Diaphragm

Mud Hog Replacement Diaphragm

Wacker Replacement Diaphragm

Gorman-Rupp Replacement Diaphragm

Multiquip Replacement Diaphragm

Riverside Replacement Diaphragm

Tsurumi Replacement Diaphragm

Compatible brands

CH&E

2″ CH&E Replacement Diaphragm – Neoprene

3″ CH&E Replacement Diaphragm – Neoprene

AMT

2″ AMT Replacement Diaphragm – Neoprene (Model 336)

3″ AMT Replacement Diaphragm – Neoprene (Model 335)

3″ AMT Replacement Diaphragm – Neoprene (No Holes)

Magnum

2″ Magnum Replacement Diaphragm – Neoprene

3″ Magnum Replacement Diaphragm – Neoprene

3″ Magnum Replacement Diaphragm – Neoprene (No Holes)

Mud Hog

2″ Mud Hog Replacement Diaphragm – Neoprene

3″ Mud Hog Replacement Diaphragm – Neoprene

3″ Mud Hog Replacement Diaphragm – Neoprene (No Holes)

Wacker

2″ Wacker Replacement Diaphragm – Neoprene

3″ Wacker Replacement Diaphragm – Neoprene (PDI3A)

Gorman-Rupp

2″ Gorman-Rupp Replacement Diaphragm – Neoprene

3″ Gorman-Rupp Replacement Diaphragm – Neoprene

3″ Gorman-Rupp Replacement Diaphragm – Neoprene (No Holes)

4″ Gorman-Rupp Replacement Diaphragm – Neoprene

Multiquip

2″ Multiquip Replacement Diaphragm – Neoprene

3″ Multiquip Replacement Diaphragm – Neoprene

Riverside

2″ Riverside Replacement Diaphragm – Neoprene

3″ Riverside Replacement Diaphragm – Neoprene

3″ Riverside Replacement Diaphragm – Neoprene (No Holes)

Tsurumi

2″ Tsurumi TD5-200 Replacement Diaphragm – Neoprene (3360-300-00-N)

3″ Tsurumi TD5-300 Replacement Diaphragm – Neoprene (2132-000-00-N)

What Makes Neoprene the Right Material for These Applications

Neoprene, chemically known as chloroprene rubber, is a synthetic elastomer that has been used in pump diaphragms for decades because of how well it balances physical toughness with flex life. Unlike natural rubber, neoprene resists weathering, ozone exposure, and flex cracking, which matters on job sites where pumps sit outdoors between uses and cycle continuously during operation.

The properties that make neoprene a practical diaphragm material for construction and dewatering work include the following.

Flex fatigue resistance: Neoprene holds up well under the repeated expansion and contraction that a diaphragm pump diaphragm experiences during normal operation. This makes it a reliable material for pumps running long daily cycles.

Weather and ozone resistance: Outdoor pump storage and operation expose diaphragms to UV light, ozone, and temperature swings. Neoprene resists surface degradation from these factors better than natural rubber.

Tensile strength and shape retention: Neoprene maintains firmness under vibration and physical load, which is why it is a common choice for high-vibration applications like concrete surface grinding and cutting operations.

Moderate chemical resistance: Neoprene handles water, mud, dilute water-based solutions, and mild chemical exposure reasonably well. It is not the correct choice for pumping oily wastewater, fuel-contaminated groundwater, or aggressive chemical solutions. For those applications, Buna/nitrile or TPE/Santoprene is the appropriate material.

Temperature range: Neoprene diaphragms generally perform across a temperature range of approximately -20 degrees C to 100 degrees C, making them suitable for most field conditions in North American climates. Always confirm the temperature range for your specific diaphragm with Ken’s Distributing if your application involves temperature extremes.

How Neoprene Compares to Other Diaphragm Materials

Choosing the wrong diaphragm material for your application is one of the most common causes of early diaphragm failure. The table below compares neoprene against rubber and Buna/nitrile across the properties that matter most for diaphragm pump applications.

Property	Neoprene Diaphragm	Buna Diaphragm	Rubber Diaphragm
Abrasion Resistance	Excellent	Good	Moderate
Weather Resistance	Excellent	Fair	Fair
Oil Resistance	Moderate	Good	Low
Temperature Range	-20°C to 100°C	-10°C to 90°C	-5°C to 80°C
Ideal Use	Construction, Dewatering	Chemical, Fuel Handling	Water Pumps, General Use

Neoprene is the right choice when the pump is handling water, mud, slurry, or groundwater without significant hydrocarbon content, and when outdoor durability and flex life are more important than oil resistance.

For a full material comparison across all four materials Ken’s Distributing carries, including TPE/Santoprene, see the main Replacement Diaphragms page.

Where Neoprene Diaphragms Are Commonly Used

The following applications represent the most common uses for neoprene replacement diaphragms in the industries Ken’s Distributing serves. These are applications where neoprene’s specific properties, flex life, weather resistance, and moderate chemical tolerance, make it a practical and cost-effective choice.

Construction dewatering: Removing groundwater, surface water, and rain accumulation from excavations, trenches, and foundation work. Pumps in these applications cycle continuously and are often left running overnight, making diaphragm durability essential.

Concrete cutting and surface grinding: Cooling water and slurry generated during diamond blade cutting and concrete surface grinding operations require a pump diaphragm that can handle abrasive, particulate-laden water without rapid wear. Neoprene performs well in this environment.

Groundwater control: Keeping excavations and worksites dry during construction phases where groundwater intrusion is ongoing. Pump run times in these applications can be extremely long, favoring materials with strong flex fatigue resistance.

Municipal utility work: Supporting temporary bypass pumping during sewer maintenance, water main repair, and stormwater management. Neoprene is appropriate here when the fluid does not contain significant chemical or hydrocarbon content.

General industrial water transfer: Moving process water, wash water, and non-aggressive water-based solutions in plant and facility environments.

If your application involves oily wastewater, fuel-contaminated groundwater, or chemically active fluids, neoprene is not the recommended material. Contact Ken’s Distributing to confirm whether Buna/nitrile or TPE/Santoprene is the better fit.

Available Neoprene Diaphragm Sizes

Ken’s Distributing carries neoprene replacement diaphragms for 2 inch, 3 inch, and 4 inch diaphragm pumps. Use the size links below to shop by pump size, or use the size reference charts to confirm your diaphragm dimensions before ordering.

Shop 2 Inch Neoprene Replacement Diaphragms
Shop 3 Inch Neoprene Replacement Diaphragms
Shop 4 Inch Neoprene Replacement Diaphragms

How to Confirm Your Neoprene Diaphragm Size

The 2 inch, 3 inch, and 4 inch designations refer to the nominal pump port or discharge size, not the actual outside diameter of the diaphragm. Diaphragm dimensions vary by pump brand and model even within the same nominal size. Always confirm the physical dimensions of the replacement neoprene diaphragm against your existing diaphragm and pump model before ordering.

To measure your existing diaphragm, lay it flat on a clean surface and take the following three measurements.

Dimension A is the outer diameter measured straight across the widest point of the diaphragm.

Dimension B is the thickness measured at the thickest point.

Dimension C is the center plate or bead diameter, if applicable to your diaphragm design.

Provide your pump brand, model number, and these three measurements when contacting Ken’s Distributing to confirm the correct neoprene diaphragm for your pump. If the pump nameplate is missing or unreadable, a photograph of the pump housing and the existing diaphragm will help our parts team identify the correct replacement.

For a full measurement walkthrough, see the measurement guide on the main Replacement Diaphragms page.

When to Inspect and Replace Your Neoprene Diaphragm

Neoprene diaphragms do not fail all at once in most cases. Catching the early signs of wear before a full failure occurs prevents unplanned downtime and protects the pump from secondary damage caused by running a compromised diaphragm.

Inspect your neoprene diaphragm when you observe any of the following.

Fluid appearing in the air chamber or at the air exhaust port, which indicates a tear, pinhole, or edge failure in the diaphragm
A drop in flow rate without any change in pump speed, suction conditions, or discharge head
Irregular or labored pump cycling sounds that suggest the diaphragm is not moving freely
Visible surface cracking, stiffening, or deformation on the diaphragm face or edges
Any pump that has been in storage for an extended period before returning to service, as neoprene can stiffen over time even without use

Inspection intervals depend on operating hours, fluid conditions, and environment. A general starting point for pumps in active construction use is an inspection every 500 to 1,000 hours of operation. Pumps running in abrasive or chemically active conditions should be inspected more frequently regardless of material.

When replacing a diaphragm, replace both diaphragms at the same time if your pump uses two. Running one new and one worn diaphragm creates uneven pressure and accelerates wear on the new diaphragm.

Other Diaphragm Materials Available

Neoprene is one of four diaphragm materials Ken’s Distributing carries for diaphragm pumps. If neoprene is not the right material for your application, the following options are available.

Rubber Replacement Diaphragms: A cost-effective option for clean water and standard dewatering where chemical exposure is minimal.

Buna/Nitrile Replacement Diaphragms: The correct choice for oily wastewater, fuel-contaminated groundwater, and hydrocarbon-containing fluids where neoprene would degrade prematurely.

TPE/Santoprene Replacement Diaphragms: The longest-lasting option for demanding continuous-duty environments where service life and chemical resistance are the primary requirements.

Frequently Asked Questions About Neoprene Replacement Diaphragms

Is neoprene better than rubber for diaphragm pumps?

For most construction and outdoor applications, yes. Neoprene outperforms natural rubber in weather resistance, ozone resistance, and flex fatigue life under outdoor conditions. Natural rubber is a cost-effective choice for clean-water applications in controlled environments, but neoprene holds up better on active job sites where pumps are exposed to the elements and run continuously.

Can I use a neoprene diaphragm if my pump originally came with a rubber diaphragm?

In many cases, yes, provided the neoprene diaphragm matches the physical dimensions of the original. The material can often be changed without modifying the pump. However, always confirm the dimensions of the replacement diaphragm against your pump model specifications before ordering. Ken’s Distributing can assist with this confirmation.

Will neoprene diaphragms hold up when pumping concrete slurry?

Neoprene performs well in concrete cutting slurry and grinding wastewater that is primarily water with suspended fine particles. If the slurry contains significant oil, fuel, or chemical content, neoprene is not the best choice. For standard construction slurry from wet cutting and grinding, neoprene is a widely used and proven material.

How do I know if my neoprene diaphragm has failed?

The most common signs of diaphragm failure are fluid appearing at the air exhaust port, reduced flow without a clear cause, and irregular pump cycling. A visual inspection of the diaphragm face for cracking, stiffening, or deformation will often confirm wear before a full failure occurs.

Do you carry neoprene diaphragms for both 2 inch and 3 inch pumps?

Yes. Ken’s Distributing carries neoprene replacement diaphragms for both 2 inch and 3 inch pump sizes, as well as larger sizes. Use the size charts above to confirm your dimensions, or contact us with your pump model number for a direct part confirmation.

Can I order neoprene diaphragms in bulk?

Yes. Ken’s Distributing offers bulk pricing and blanket order programs for contractors, rental companies, municipalities, and industrial operations that need a consistent supply of neoprene diaphragms. Contact us with your pump model, diaphragm size, and estimated annual volume for pricing.