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Riverside Replacement Diaphragms

Durable Riverside Replacement and Repair Parts

Searching for Riverside replacement diaphragms that other parts houses no longer carry? Many suppliers gave up on legacy diaphragm pumps years ago. Ken’s Distributing Company did not. We supply high-grade Riverside replacement diaphragms designed to fit the most common 2-inch and 3-inch Riverside pumps still in service across construction, agricultural, municipal, and industrial work.

A working Riverside pump beats a brand-new import unit on the same site. With a fresh diaphragm and a few wear parts, an older Riverside pump can deliver another full season of reliable output.

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Available materials

Neoprene

Rubber

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Neoprene

2 Inch Riverside Replacement Diaphragm - Neoprene

2″ Riverside Replacement Diaphragm – Neoprene

3 Inch Riverside Replacement Diaphragm - Neoprene

3″ Riverside Replacement Diaphragm – Neoprene

4 Inch Gorman-Rupp Replacement Diaphragm - TPE

3″ Riverside Replacement Diaphragm – Neoprene (No Holes)

Rubber

2 Inch Riverside Replacement Diaphragm - Rubber

2″ Riverside Replacement Diaphragm – Rubber

3 Inch Riverside Replacement Diaphragm - Rubber

3″ Riverside Replacement Diaphragm – Rubber

Get a Fast Quote from a Pump Specialist

When downtime means lost productivity, you need Riverside replacement diaphragms in your hands fast. Our parts team can match your pump and ship the right part the same day on most in-stock orders.

Call (303) 699-7845 to confirm the correct fit for your Riverside pump.

Compatible Replacement Sizes

We stock Riverside replacement diaphragms in the two most common sizes used in construction and dewatering work, with custom fits available on request.

2-Inch Diaphragm Replacement

Standard 2-inch replacement diaphragms for Riverside pumps used in trench dewatering, light slurry transfer, and general site work. Available in all four compounds.

3-Inch Diaphragm Replacement

Larger 3-inch replacement diaphragms for Riverside pumps moving higher volume, heavier solids, and full-day jobsite loads. Available in all four compounds.

Custom Sizes for Select Industrial Pumps

Older or specialty Riverside pumps sometimes need a non-standard diaphragm. Send a photo of the pump tag and a measurement of the existing diaphragm, and our team can source the correct fit.

Compatible Pump Brands and Models

Our Riverside replacement diaphragms are sized to match common Riverside diaphragm pump configurations, including older models that may no longer have OEM support. If your pump tag is faded or missing, send a photo of the housing and a measurement of the existing diaphragm. Our parts team can usually identify the correct fit from the bolt pattern and dimensions.

Compatible diaphragm replacements include:

  • 2-inch Riverside diaphragm pumps
  • 3-inch Riverside diaphragm pumps
  • Trailer-mounted Riverside dewatering units
  • Legacy and discontinued Riverside pump models
  • Engine-driven and electric-drive configurations

Available Materials

Every Riverside replacement diaphragm in our inventory is available in four proven compounds. The right material depends on the fluid type, temperature range, and contamination level in your application.

Neoprene Diaphragms

Neoprene (chloroprene rubber) offers excellent strength, flexibility, and resistance to abrasion, weathering, and moderate oil exposure. A balanced all-around choice for outdoor construction and dewatering use.

  • Excellent abrasion and weather resistance
  • Moderate oil resistance
  • Long-lasting durability under heavy use
  • Temperature range: -20°C to 100°C

Rubber Diaphragms (General Purpose)

General-purpose rubber diaphragms balance flexibility, durability, and cost. Ideal for non-aggressive fluids such as water, air, and mild chemicals in light-duty or routine maintenance applications.

  • Affordable and widely compatible
  • Excellent flexibility and elasticity
  • Easy installation in standard housings
  • Suitable for fluid transfer, air systems, and pool applications

Buna-N (Nitrile) Diaphragms

Buna-N is the right choice when the pumped fluid contains petroleum, fuels, or hydrocarbons. Excellent oil and fuel resistance with strong tensile strength under pressure.

  • Excellent resistance to fuels, oils, and hydrocarbons
  • High tensile strength and flexibility under pressure
  • Temperature range: -40°F to 250°F
  • Limited ozone and weather resistance — best for sealed applications

TPE (Santoprene) Diaphragms

Thermoplastic Elastomer diaphragms deliver superior chemical resistance and impressive flex life. Built for the most demanding jobs and the widest range of fluids, from acids and alkalis to abrasive slurries.

  • Superior resistance to acids, alkalis, and solvents
  • Wide temperature tolerance for hot and cold environments
  • Solid performance with abrasive materials and slurries
  • Long flex life under high cycle counts

Why Choose Riverside Replacement Diaphragms from Ken's?

Riverside diaphragm pumps were built simple, strong, and serviceable. That is exactly why so many crews refuse to retire them. The diaphragm is the heart of that durability, and every pumping cycle moves water, debris, and abrasives through the chamber. Even premium rubber wears under that load.

Key advantages include:

  • OEM-fit dimensions for clean installation in older housings
  • Four compound options for any fluid type
  • Support for legacy and discontinued pump models
  • Tear strength against grit, sand, and stones
  • Long flex life under high cycle counts
  • Heat tolerance during full-day pumping

Applications of Riverside Diaphragm Replacement Parts

Riverside diaphragm pumps serve a wide range of industries. The compound you choose depends on the fluid and the conditions.

Construction and Dewatering

Perfect for Riverside pumps used on construction sites, removing standing water, and handling slurries or sediment. Neoprene is the most common choice for this kind of mixed-condition outdoor work.

Agricultural and Irrigation Use

Reliable diaphragm performance keeps Riverside pumps consistent during irrigation, drainage, and fertilizer mixing. Rubber and Neoprene compounds handle these jobs well.

Water-Handling and Pool Applications

Used in Riverside pumps for circulating and filtering pool water, fountains, and small irrigation systems that need steady, low-pressure flow.

Industrial Fluid Transfer

Riverside pumps in light industrial work often handle mild chemical exposure. Buna-N and TPE compounds extend service life in those conditions.

How to Know When to Replace a Diaphragm

A worn Riverside diaphragm rarely fails all at once. Output drops gradually until the pump will not prime or hold suction. Catch the wear early and you save the rest of the pump from costly repair.

Watch for these warning signs:

  • Pump takes longer to prime than it used to
  • Discharge flow drops noticeably at full throttle
  • Air bubbles appear in the discharge stream
  • Visible cracks, splits, or thin spots in the diaphragm rubber
  • Water seeps from around the diaphragm cover plate
  • Pump vibrates more than normal during operation

Replacing the diaphragm at the first sign of wear prevents debris from reaching the valves, seats, and connecting rod, which are far more expensive to repair than the diaphragm itself.

Replacement and Maintenance Tips

A Riverside replacement diaphragm performs best when installed correctly and supported by clean wear parts.

  1. Inspect diaphragms every 500 to 1,000 hours of operation for wear, cracks, or thinning
  2. Replace both diaphragms at the same time to maintain balanced pressure
  3. Check valves and seats for buildup or debris that could reduce pump efficiency
  4. Use the compound that matches your fluid type and operating conditions
  5. Torque cover plate bolts evenly in a star pattern to prevent uneven sealing
  6. Flush the pump after handling muddy, chemical-laden, or fuel-contaminated water
  7. Store the pump out of direct sunlight to slow ozone and UV breakdown

Following these steps can extend diaphragm life and protect the valves, seats, and connecting rod from secondary damage.

Choosing Between Neoprene, Buna, and TPE Diaphragms

Matching the compound to the fluid is the single most important sizing decision when ordering a Riverside replacement diaphragm:

  • Clean water and general use — Rubber or Neoprene
  • Outdoor exposure and moderate oil contact — Neoprene
  • Fuel, diesel, or hydraulic fluid contamination — Buna-N (Nitrile)
  • Acids, solvents, abrasive slurry, or high cycle counts — TPE (Santoprene)

Not sure which fits your job? Our parts team can recommend the right compound based on the water and the workload.

Why Buy Riverside Diaphragms from Ken's Distributing?

Ken’s Distributing Company has supplied diaphragm pump replacement parts to contractors, rental fleets, and municipal water crews since 1991. We are America’s Water Pump Parts Distributor and an authorized dealer for Franklin Electric, Monarch, CH&E, Generac Magnum, and Red Lion.

Our customers stay with us because the parts fit, the support team understands the equipment, and we keep stock on lines other suppliers no longer carry.

What you get when you order from Ken’s:

  • Fast shipping on standard and hard-to-find parts (most orders ship same day)
  • Expert support to identify the correct diaphragm for your pump model
  • Competitive pricing and bulk order options
  • Blanket order programs for contractors and rental fleets
  • Free shipping on complete pump orders
  • Phone and email parts desk staffed by people who know diaphragm pumps

We are committed to helping you reduce downtime and extend equipment life with dependable replacement parts.

Order Your Riverside Replacement Diaphragm Today

When your Riverside pump needs repair, trust Ken’s Distributing for the best Riverside replacement diaphragms in stock and ready to ship. Whether you need a 2-inch or 3-inch diaphragm in Rubber, Neoprene, Buna-N, or TPE, we have the right part to restore full performance and minimize downtime.

Request a quote online, or reach our parts team direct.

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