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Mud Hog Replacement Diaphragms for Diaphragm Pumps

Mud Hog replacement diaphragms for diaphragm pumps are available through Ken’s Distributing in rubber, neoprene, Buna/nitrile, TPE, and Viton compounds, with OEM-fit part numbers for Mud Hog 200 Series, 300 Series, and 400 Series pump models used in construction dewatering, municipal utility work, agricultural transfer, industrial slurry pumping, and flood and emergency response operations. Ken’s Distributing stocks both individual Mud Hog replacement diaphragms and bulk orders of 15 units or more, with discount pricing available for contractors, distributors, and rental companies.

Each Mud Hog pump in the 200, 300, and 400 Series uses two diaphragms for a complete replacement. Use the model and part number tables below to identify the correct diaphragms for your pump, then contact Ken’s Distributing to confirm stock and place your order.

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Available materials

Neoprene

Rubber

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Neoprene

2 Inch Mud Hog Replacement Diaphragm - Neoprene

2″ Mud Hog Replacement Diaphragm – Neoprene

3 Inch Mud Hog Replacement Diaphragm - Neoprene

3″ Mud Hog Replacement Diaphragm – Neoprene

3 Inch Mud Hog Replacement Diaphragm - Neoprene (No Holes)

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

Rubber

2 Inch Mud Hog Replacement Diaphragm - Rubber

2″ Mud Hog Replacement Diaphragm – Rubber

3 Inch Mud Hog Replacement Diaphragm - Rubber

3″ Mud Hog Replacement Diaphragm – Rubber

How Mud Hog Diaphragm Pumps Work

Mud Hog diaphragm pumps are positive-displacement pumps that use two flexible diaphragms operating in alternating strokes to move fluid through the pump body. One diaphragm creates a suction stroke that draws fluid into the pump while the other creates a discharge stroke that pushes fluid out through the discharge port. The two diaphragms alternate continuously, which produces a more consistent flow than a single-diaphragm design.

The diaphragms physically separate the air chambers from the liquid chambers inside the pump. This separation is what allows Mud Hog pumps to handle fluids containing sand, mud, small solids, and debris without an impeller, and without those solids contacting the internal drive components. Because the diaphragm is the only barrier between the fluid and the pump’s internal mechanism, selecting the correct compound for the fluid being pumped is as important as selecting the correct size and part number.

Because Mud Hog pumps use two diaphragms, both diaphragms should be replaced at the same time when either one shows wear. Running one new diaphragm alongside a worn one creates uneven stroke pressure, reduces pump efficiency, and accelerates wear on the new diaphragm.

Where Mud Hog Pumps Are Used

Mud Hog diaphragm pumps are used across a wide range of industries and applications where the fluid contains solids, debris, or contaminants that conventional impeller pumps cannot handle reliably.

Construction dewatering and excavation drainage: Active construction sites, foundation excavations, trenches, and utility corridors where groundwater, surface water, and sediment-laden slurry must be removed continuously.

Municipal utility maintenance and bypass: Sewer bypass pumping, water main repair support, and stormwater management operations where the fluid may contain solids or debris.

Agricultural irrigation and liquid transfer: Pond and lagoon pumping, irrigation system water supply, and agricultural liquid transfer in applications where the fluid is clean to moderately turbid water.

Industrial wastewater and slurry transfer: Moving process water, industrial slurry, and wastewater in plant and facility environments where the fluid carries suspended solids or moderate chemical content.

Emergency flood and storm cleanup: High-volume, continuous-duty dewatering in flood response, storm damage remediation, and emergency water removal operations.

Grinding and grooving operations: Pumping slurry, cooling water, and cutting fluid waste generated during diamond blade concrete cutting, surface grinding, and joint sawing. Mud Hog pumps are a standard choice in this application because of their ability to pass fine concrete particles without clogging.

Mud Hog 200 Series, 2 Inch Replacement Diaphragms

Compatible Mud Hog 200 Series Models

The 2 inch Mud Hog replacement diaphragm fits the following 200 Series Mud Hog pump models:

201, 202, 202D, 203, 204.

Each pump in the 200 Series uses two diaphragms for a complete replacement. Discharge connection is 2 inch.

2 Inch Mud Hog Diaphragm Part Numbers by Compound

Part Number Compound Best Application
P2331R Rubber Clean water and lightly sediment-laden water in standard dewatering applications. Most cost-effective option for 200 Series pumps handling water without chemical or hydrocarbon content.
P2331N Neoprene Abrasion and chemical resistant for construction slurry, dirty water, and outdoor pump operation. Most commonly specified compound for 200 Series pumps in active construction use.
P2331B Buna/Nitrile Oil, fuel, and hydrocarbon-contaminated water. Correct specification when petroleum content is present in the fluid.
P2331TPE TPE Extended-life compound for high-cycle, continuous-duty, or chemically demanding 200 Series applications where rubber and neoprene require replacement more often than the operation can sustain.

Alternate 2 Inch Compound Options

SA-10003B: Buna/Nitrile
SA-10003N: Neoprene
SA-10003V: Viton
SA-10004N: Neoprene with Cloth Insert

Note on Viton: Viton is a fluoroelastomer compound with superior resistance to aggressive chemicals, fuels, and elevated temperatures compared to Buna/nitrile and TPE. It is not required for standard construction or dewatering applications and carries a higher per-unit cost. Specify Viton only when the fluid being pumped exceeds the chemical compatibility of Buna/nitrile or TPE. Contact Ken’s Distributing to confirm Viton availability before specifying it.

Note on cloth insert diaphragms: The neoprene with cloth insert option (SA-10004N) provides additional dimensional stability and tear resistance in high-cycle applications where the diaphragm experiences significant physical stress during the pumping stroke.

Typical Applications for Mud Hog 200 Series Pumps

  • Light construction site drainage and trench dewatering
  • Irrigation system water supply and agricultural water transfer
  • Municipal utility maintenance at lower flow volumes
  • General water transfer in clean to lightly turbid water

Mud Hog 300 Series, 3 Inch Replacement Diaphragms

Compatible Mud Hog 300 Series Models

The 3 inch Mud Hog replacement diaphragm fits the following 300 Series Mud Hog pump models:

302, 302B, 302C, 304, 305.

Each pump in the 300 Series uses two diaphragms for a complete replacement. Discharge connection is 3 inch.

3 Inch Mud Hog Diaphragm Part Numbers by Compound

Part Number Compound Best Application
P2726R Rubber Flexible, cost-effective diaphragm for clean water and light sludge in standard 300 Series dewatering applications without chemical or hydrocarbon exposure.
P2726N Neoprene Durable, abrasion-resistant compound for 300 Series pumps in construction dewatering, slurry transfer, sediment-laden groundwater, and outdoor operation.
P2726B Buna/Nitrile Oil and fuel resistant for 300 Series pumps handling hydrocarbon-contaminated water on industrial, demolition, or environmental remediation sites.
P2726TPE TPE Extended-life compound for 300 Series pumps in demanding continuous-duty applications, abrasive slurry transfer, and environments where rubber and neoprene wear out too quickly.

Alternate 3 Inch Compound Options

SA-10001B: Buna/Nitrile
SA-10001N: Neoprene
SA-10002N: Neoprene with Cloth Insert

The neoprene with cloth insert option (SA-10002N) is worth considering for 300 Series Mud Hog pumps in high-cycle construction applications, concrete cutting slurry transfer, and any application where additional diaphragm tear resistance is beneficial.

Typical Applications for Mud Hog 300 Series Pumps

  • Active construction site dewatering at higher flow volumes than the 200 Series manages
  • Municipal bypass operations for sewer maintenance and water main repair
  • Agricultural lagoon and pond pumping
  • Industrial wastewater and slurry transfer in plant environments
  • Grinding and grooving slurry management on concrete cutting job sites

Mud Hog 400 Series, 4 Inch Replacement Diaphragms

Compatible Mud Hog 400 Series Models

The 4 inch Mud Hog replacement diaphragm fits the following 400 Series Mud Hog pump models:

403, 404, 405, 414, 419, 445, 446.

Each pump in the 400 Series uses two diaphragms for a complete replacement. Discharge connection is 4 inch.

4 Inch Mud Hog Diaphragm Compounds Available

4 inch Mud Hog replacement diaphragms are available in rubber, neoprene, Buna/nitrile, and TPE compounds. Contact Ken’s Distributing for current 4 inch Mud Hog part numbers, availability by compound, repair kits, and compatible flapper and valve assemblies.

Call (303) 699-7845 or contact us online to confirm current stock and part numbers for your 400 Series Mud Hog pump.

Typical Applications for Mud Hog 400 Series Pumps

  • Large-volume construction dewatering where the flow capacity of a 3 inch pump is insufficient
  • Flood control and emergency water removal requiring maximum pump throughput
  • Sewer bypass operations during major municipal infrastructure maintenance
  • High-volume industrial slurry pumping in mining, aggregate, and heavy industrial environments

Selecting the Right Compound for Your Mud Hog Pump

The compound selection process applies the same way across the Mud Hog 200, 300, and 400 Series. Match the compound to the fluid being pumped and the daily operating conditions of your specific application.

Clean water, standard groundwater, light sediment without chemical or hydrocarbon content: Rubber or neoprene. Choose rubber for the lowest cost in clean-water applications. Choose neoprene for better outdoor durability, abrasion resistance, and flex life in active construction environments.

Construction slurry, concrete cutting wastewater, sediment-laden groundwater, outdoor pump operation: Neoprene. The combination of abrasive fine particles and outdoor operating conditions favors neoprene over rubber for Mud Hog pumps in construction use. The neoprene with cloth insert option provides additional tear resistance in high-physical-stress applications.

Oily wastewater, fuel-contaminated groundwater, petroleum-containing fluids: Buna/nitrile. Rubber and neoprene degrade in contact with oil and fuel. Buna/nitrile is the correct specification for any Mud Hog pump application where hydrocarbon content is present in the fluid being pumped.

Continuous-duty high-cycle operation, abrasive slurry, mild chemical exposure, demanding environments where rubber and neoprene replacement frequency is too high for the operation: TPE. The higher per-unit cost compared to rubber and neoprene is typically offset by longer service intervals in these conditions.

Aggressive chemicals or fluids exceeding Buna/nitrile or TPE compatibility: Viton (available for 200 Series applications via SA-10003V). Contact Ken’s Distributing to confirm Viton suitability for your specific fluid before specifying it.

If your application does not fit clearly into these categories, contact Ken’s Distributing with your Mud Hog pump model number and a description of the fluid being pumped. Our parts team can confirm the correct compound for your specific conditions.

How to Identify a Worn Mud Hog Diaphragm

Mud Hog diaphragm wear typically presents as gradual performance loss before a complete failure. Because Mud Hog pumps use two diaphragms, wear on one diaphragm affects the balance of the entire pump, which is why the performance decline from a worn diaphragm is often noticeable before the diaphragm fails completely.

Replace or inspect your Mud Hog diaphragms when you observe any of the following.

  • The pump takes noticeably longer to prime than when the diaphragms were new
  • Discharge flow drops at full throttle without a change in suction conditions or discharge head
  • Air bubbles appear in the discharge stream, indicating the diaphragm is allowing air bypass
  • Visible cracking, surface stiffening, fabric showing through the diaphragm face, or permanent deformation during physical inspection
  • Fluid appearing at the air exhaust port or in the air chamber
  • Increased pump vibration or noise during normal operation compared to when the diaphragms were in good condition

Replace both diaphragms at the same time whenever either one requires replacement. Running one new Mud Hog diaphragm alongside a worn one creates uneven stroke pressure across the two chambers, reduces overall pump efficiency, and accelerates wear on the new diaphragm.

Mud Hog Diaphragm Installation and Maintenance

Installation

Confirm both replacement diaphragm part numbers and compounds match your Mud Hog pump model and application before installation. Remember that a complete replacement requires two diaphragms per pump.

Torque the cover plate bolts evenly in a cross or star pattern on both diaphragm covers. Uneven torque creates localized stress on the diaphragm sealing edges and is a common cause of early edge failures on Mud Hog pumps. Follow the torque specifications from the Mud Hog service documentation for your specific pump model.

Inspect flappers and valve assemblies at every diaphragm replacement. Worn flappers limit the efficiency gain from new diaphragms and can cause erratic flow that makes a correctly installed diaphragm appear to be performing poorly. Replace flappers and valve assemblies on high-hour pumps at the same service interval as the diaphragm replacement.

Maintenance

  • Inspect both Mud Hog diaphragms at regular intervals in active service. A starting point for inspection frequency in construction use is every 500 to 1,000 operating hours. Pumps handling abrasive slurry or running continuously should be inspected more frequently.
  • Flush the pump after handling sediment-laden, oily, or chemically active fluids to prevent these materials from drying inside the pump housing, which accelerates wear on diaphragms, flappers, and valve seats.
  • Avoid running Mud Hog pumps dry. Dry running removes the fluid that cushions both diaphragms during their stroke and causes rapid wear, particularly on rubber and neoprene compounds.
  • Store Mud Hog pumps out of direct sunlight when not in use to reduce UV and ozone degradation on rubber and neoprene diaphragms.

Bulk Pricing and Blanket Orders for Mud Hog Diaphragms

Contractors, rental companies, municipalities, and industrial operations running multiple Mud Hog pumps benefit from keeping diaphragm inventory on hand before a failure occurs. Because each Mud Hog pump uses two diaphragms per replacement, maintaining a supply of pre-paired diaphragm sets prevents a single pump failure from stopping work while parts are sourced.

Ken’s Distributing offers bulk pricing on orders of 15 units or more across all compounds and all three Mud Hog pump series. Blanket order programs are available for organizations that need a reliable year-round supply of Mud Hog replacement diaphragms without the risk of parts unavailability between orders.

Contact Ken’s Distributing with your Mud Hog pump model, diaphragm series, compound preference, and estimated annual volume for bulk pricing and blanket order program details.

Learn More About Blanket Orders

Related Parts for Mud Hog Pumps

The following parts are commonly inspected and replaced alongside Mud Hog diaphragms. Addressing related wear components at the same service interval as the diaphragm replacement maximizes the performance benefit of the new diaphragms and reduces the likelihood of a follow-on service call.

Flappers and valve assemblies: The one-way flow control components that work in combination with the diaphragms to direct fluid through the pump. Worn flappers cause erratic flow and reduce pump efficiency regardless of diaphragm condition.

Complete Mud Hog repair kits: Ken’s Distributing carries complete repair kits for Mud Hog 200, 300, and 400 Series pumps that include both diaphragms, flappers, valve assemblies, and other wear components in a single kit. A complete kit is often more cost-effective than sourcing individual components separately, particularly for high-hour pumps receiving a full service.

Contact Ken’s Distributing for current repair kit availability and part numbers for your specific Mud Hog pump model.

Other Diaphragm Pump Brands We Support

Ken’s Distributing carries replacement diaphragms for all major diaphragm pump brands used in North American construction, industrial, and municipal markets. If you operate other pump brands alongside your Mud Hog units, the following pages cover diaphragm replacements for each brand.

CH&E Replacement Diaphragms
Magnum Replacement Diaphragms
AMT Replacement Diaphragms
Wacker Replacement Diaphragms
Gorman-Rupp Replacement Diaphragms
Multiquip Replacement Diaphragms
Riverside Replacement Diaphragms
Tsurumi Replacement Diaphragms

For diaphragm selection by material rather than brand, see the material-specific pages below.

Rubber Replacement Diaphragms
Neoprene Replacement Diaphragms
Buna/Nitrile Replacement Diaphragms
TPE Santoprene Replacement Diaphragms

Frequently Asked Questions About Mud Hog Replacement Diaphragms

All Mud Hog 200, 300, and 400 Series pumps use two diaphragms. A complete diaphragm replacement requires two diaphragms per pump. Always replace both diaphragms at the same time to maintain balanced stroke pressure and avoid accelerating wear on the new diaphragm by pairing it with a worn one.

Identify your Mud Hog pump model number from the pump nameplate and match it to the 200, 300, or 400 Series tables above. The 200 Series models use the P2331 part number family, the 300 Series models use the P2726 part number family, and the 400 Series part numbers are available by contacting Ken’s Distributing directly. If your model number is not listed, contact Ken’s Distributing with the model number and we will confirm the correct part.

Neoprene is the most commonly specified compound for Mud Hog pumps in concrete cutting and surface grinding applications. The slurry in these operations is primarily water with fine suspended concrete particles, which is an environment where neoprene’s abrasion resistance and outdoor durability are well suited. The neoprene with cloth insert option provides additional tear resistance if the pump handles particularly abrasive material or runs at high cycle counts.

Viton is available for Mud Hog 200 Series pumps via part number SA-10003V. Viton is a high-cost specialty compound intended for applications involving aggressive chemicals or fluids that exceed the compatibility of Buna/nitrile and TPE. It is not needed for standard construction dewatering, slurry transfer, or groundwater removal. Contact Ken’s Distributing to confirm whether Viton is the correct specification for your specific fluid before ordering.

A neoprene diaphragm with a cloth insert has a fabric layer embedded within the diaphragm body. This provides additional dimensional stability under pressure and improved tear resistance compared to a standard neoprene diaphragm. The cloth insert option is worth considering for high-cycle Mud Hog applications where the diaphragm experiences significant physical stress. For standard construction dewatering, the standard neoprene diaphragm is typically sufficient.

No. Both diaphragms in a Mud Hog pump should be the same compound and the same part number. Mixing compounds creates differences in flex stiffness and stroke behavior between the two chambers, which reduces pump efficiency and can cause uneven wear. Always replace both diaphragms with matched parts.

Yes. Ken’s Distributing stocks Mud Hog replacement diaphragms for the 200, 300, and 400 Series. Part numbers for the 200 and 300 Series are listed in the tables above. For 400 Series part numbers and current availability by compound, contact Ken’s Distributing directly.

Yes. Orders of 15 units or more qualify for bulk discount pricing across all compounds and all three Mud Hog series. Blanket order programs are also available for contractors, rental yards, and organizations managing multiple Mud Hog pumps. Contact Ken’s Distributing with your pump series, compound preference, and estimated annual volume for pricing details.

Yes. Ken’s Distributing ships Mud Hog replacement diaphragms to all 50 U.S. states and Canada. Contact us for shipping details on bulk or blanket orders.

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