Buna (Nitrile) Diaphragms for 2″ & 3″ Diaphragm Pumps
Buna/Nitrile Replacement Diaphragms for Diaphragm Pumps are designed for applications involving oil, fuel, petroleum-based fluids, oily wastewater, and other operating conditions where greater hydrocarbon resistance is required. Ken’s Distributing supplies Buna-N and nitrile pump diaphragms in multiple sizes and configurations for industrial, construction, municipal, and fluid-transfer applications throughout the U.S. and Canada.
Shop Buna replacement diaphragms by pump brand, model, or size. If you are unsure which diaphragm is correct, provide your pump model, part number, diaphragm dimensions, and fluid application to Ken’s Distributing for assistance identifying the appropriate replacement.
Why Choose Buna/Nitrile Replacement Diaphragms?
Buna-N, also known as nitrile rubber or NBR, is a synthetic elastomer commonly used in pump diaphragms where resistance to oils, fuels, lubricants, and petroleum-based fluids is important. Its combination of flexibility, mechanical strength, and hydrocarbon resistance makes Buna a practical diaphragm material for demanding industrial and fluid-handling applications.
Buna diaphragms are particularly useful when standard rubber or neoprene may deteriorate more quickly because of repeated exposure to petroleum-based fluids.
Oil and fuel resistance: Buna provides strong resistance to many petroleum oils, fuels, lubricants, and hydrocarbon-containing fluids.
Mechanical durability: Nitrile maintains useful tensile strength and flexibility while repeatedly cycling inside a diaphragm pump.
Reliable sealing performance: Buna maintains the elasticity needed for consistent diaphragm movement and sealing under normal pump operating conditions.
Industrial versatility: Buna diaphragms are commonly used in fuel transfer, oily wastewater handling, industrial fluid movement, equipment maintenance, and other applications where petroleum resistance is required.
Environmental limitations: Buna generally provides less resistance to prolonged sunlight, ozone, and outdoor weather exposure than materials such as neoprene. Material selection should always consider both the fluid being pumped and the surrounding operating environment.
Common Buna Diaphragm Sizes and Replacement Options
Ken’s Distributing supplies Buna and nitrile replacement diaphragms in a range of sizes and configurations for commonly used diaphragm pumps. Pump size alone does not determine the correct diaphragm, so always confirm the pump model, diaphragm dimensions, material requirements, and existing part number when available.
Common diaphragm pump sizes include:
- 2 Inch Replacement Diaphragms
- 3 Inch Replacement Diaphragms
- 4 Inch Replacement Diaphragms
- Additional Sizes for Select Pump Models
You can also browse replacement diaphragms by pump size:
Buna Diaphragms by Pump Brand
Use your pump manufacturer and model number to narrow your search for the correct replacement diaphragm. Each brand page contains diaphragm and pump-part options for that manufacturer.
- CH&E Replacement Diaphragms
- Magnum Replacement Diaphragms
- AMT Replacement Diaphragms
- Mud Hog Replacement Diaphragms
- Wacker Replacement Diaphragms
- Gorman-Rupp Replacement Diaphragms
- Multiquip Replacement Diaphragms
- Riverside Replacement Diaphragms
- Tsurumi Replacement Diaphragms
Select the manufacturer of your pump and confirm the model and diaphragm specifications before ordering. If you cannot identify the correct part, Ken’s Distributing can assist using your pump information and existing diaphragm measurements.
What Are Buna Diaphragms Made Of?
Buna-N is a synthetic rubber material also known as nitrile rubber or NBR. It is commonly selected for sealing and diaphragm applications because of its resistance to petroleum-based oils, fuels, lubricants, and other hydrocarbon-containing fluids.
The exact performance of a Buna diaphragm depends on the rubber compound, fluid being pumped, operating temperature, pump design, and service conditions.
Key Properties of Buna/Nitrile
- Strong resistance to many petroleum-based oils, fuels, and lubricants
- Good tensile strength and flexibility
- Good mechanical performance under repeated pump cycling
- Useful resistance to many hydrocarbon-containing fluids
- More limited resistance to prolonged sunlight, ozone, and outdoor weather exposure than some alternative materials
These properties make Buna diaphragms particularly useful in industrial pumping applications where petroleum resistance is more important than long-term outdoor weather resistance.
Benefits of Buna Diaphragms for Industrial Pump Applications
Buna offers a practical combination of durability, fluid resistance, and cost for diaphragm pumps operating around oil, fuel, and petroleum-based products.
Key advantages include:
- Strong performance in oily and hydrocarbon-containing environments
- Resistance to swelling and degradation from many petroleum-based fluids
- Good flexibility during repeated diaphragm pump cycles
- Useful mechanical strength for demanding pump applications
- Cost-effective performance for many industrial fluid-handling systems
The correct diaphragm should always be selected according to the pump requirements and the actual fluid being handled. Contact Ken’s Distributing if you need help determining whether Buna is appropriate for your application.
Common Applications for Buna Pump Diaphragms
Buna replacement diaphragms are commonly used in applications where oil, fuel, lubricants, or other petroleum-based fluids may come into contact with the diaphragm.
Fuel transfer: Buna is frequently selected for pump applications involving petroleum fuels and related hydrocarbon fluids.
Oily wastewater: Industrial and construction sites may produce water contaminated with oils, lubricants, or petroleum residue. Buna provides greater resistance to these fluids than standard natural rubber.
Fuel-contaminated groundwater: Sites involving equipment leaks, petroleum storage, or industrial activity may require a diaphragm with improved hydrocarbon resistance.
Lubricant handling: Buna can be appropriate for pumping systems that encounter petroleum-based lubricants and oils.
Industrial fluid transfer: Nitrile diaphragms are used in a variety of industrial pumping environments where the fluid characteristics call for greater petroleum resistance.
Construction and equipment service: Buna may be selected where construction wastewater, wash water, or process fluids contain oil or fuel contamination.
For any application involving unusual chemicals, solvents, elevated temperatures, or mixed fluids, confirm material suitability before ordering.
Buna vs. Neoprene Diaphragms
Buna and neoprene are both widely used diaphragm materials, but each performs differently depending on the fluid and operating environment. Buna is generally selected when petroleum resistance is the priority, while neoprene offers stronger resistance to outdoor weathering and ozone exposure.
| Property | Buna/Nitrile Diaphragm | Neoprene Diaphragm |
|---|---|---|
| Oil Resistance | Excellent | Limited to Moderate |
| Fuel Resistance | Excellent | Limited to Moderate |
| Weather Resistance | Fair | Excellent |
| Ozone Resistance | Fair | Excellent |
| Flex Performance | Good | Very Good |
| Common Applications | Oily Water, Fuel, Petroleum-Based Fluids | Construction, Groundwater, General Dewatering |
If your pump handles petroleum-based fluids, oily wastewater, or fuel-contaminated water, Buna may be the more appropriate material. For construction dewatering and outdoor applications without significant petroleum exposure, Neoprene Replacement Diaphragms may be a better choice.
For a broader comparison of available materials, visit the main Replacement Diaphragms page.
How to Identify the Correct Buna Replacement Diaphragm
Choosing a replacement diaphragm requires more than knowing the material. The pump model, diaphragm dimensions, mounting design, and application should all be confirmed before ordering.
Start with the following information:
- Pump manufacturer
- Pump model number
- Existing diaphragm part number, if available
- Diaphragm material
- Outside diameter and other required physical measurements
- Fluid being pumped
- Operating conditions
If the pump identification plate or existing part number is unavailable, photographs of the pump and diaphragm may help Ken’s Distributing identify the appropriate replacement.
When to Inspect and Replace a Buna Diaphragm
Regular diaphragm inspection helps prevent unexpected pump downtime and allows worn components to be replaced before they cause a larger problem.
Inspect your Buna diaphragm if you notice any of the following:
- Reduced pump pressure or flow
- Irregular or labored pump cycling
- Visible cracks, cuts, bulging, or deformation
- Hardening or loss of flexibility
- Fluid leakage or loss of prime
- Deterioration around the diaphragm edge or mounting area
Diaphragm service life varies according to fluid type, operating hours, temperature, pump setup, pressure, and maintenance conditions. Follow the pump manufacturer’s maintenance recommendations and inspect wear components regularly.
Buna Replacement Diaphragm Installation Tips
Correct installation is important for diaphragm performance and service life. Always follow the service procedure provided for your specific pump model.
- Clean the pump housing and diaphragm mounting surfaces before installation.
- Inspect surrounding components for corrosion, debris, sharp edges, or damage.
- Confirm that the diaphragm is positioned correctly before tightening hardware.
- Use the correct fasteners, plates, clamps, and related components specified for the pump.
- Tighten hardware according to the pump manufacturer’s recommended procedure.
- Inspect related wear components while the pump is disassembled.
If you need help identifying the correct diaphragm or related repair parts, contact Ken’s Distributing with your pump model and existing part information.
Other Replacement Diaphragm Materials
Buna/Nitrile is one of several diaphragm materials available from Ken’s Distributing. The best material depends on the fluid, operating environment, and pump requirements.
Neoprene Replacement Diaphragms: A durable choice for construction dewatering, groundwater control, slurry, and outdoor applications where weather and flex resistance are important.
Rubber Replacement Diaphragms: A cost-effective option for clean water and standard dewatering applications where oil and chemical exposure are minimal.
TPE/Santoprene Replacement Diaphragms: A durable option for demanding applications where flex life, chemical resistance, and extended service intervals are important.
Why Buy Buna Diaphragms from Ken’s Distributing?
Ken’s Distributing supplies replacement diaphragms and pump repair components for contractors, municipalities, rental fleets, industrial facilities, and other operations that depend on reliable pumping equipment.
Customers can contact Ken’s Distributing for assistance identifying the correct replacement diaphragm using pump model numbers, part numbers, diaphragm measurements, and application details.
Available services include:
- Replacement diaphragm and pump-part assistance
- Help identifying parts by pump brand and model
- Replacement options for common and harder-to-find pump applications
- Bulk pricing for qualifying orders
- Blanket order programs for recurring diaphragm requirements
Frequently Asked Questions About Buna/Nitrile Replacement Diaphragms
What is a Buna diaphragm?
A Buna diaphragm is manufactured from nitrile rubber, also called NBR or Buna-N. The material is commonly used in pump applications requiring resistance to petroleum oils, fuels, lubricants, and related hydrocarbon-containing fluids.
When should I use a Buna diaphragm instead of rubber?
Buna is generally preferred when the fluid being pumped contains petroleum-based oils, fuel, lubricants, or similar hydrocarbons. Standard rubber is more commonly used for clean water and general dewatering applications where petroleum exposure is not present.
Is Buna the same as nitrile?
Yes. Buna-N, nitrile rubber, and NBR are commonly used names for the same general family of synthetic rubber materials used in seals, diaphragms, and other fluid-handling components.
How do I find the correct Buna diaphragm for my pump?
Start with your pump manufacturer and model number. If available, also provide the existing diaphragm part number, material, and physical measurements. Ken’s Distributing can use this information to help identify the appropriate replacement diaphragm for your pump.
Do you carry Buna diaphragms for 2 inch and 3 inch diaphragm pumps?
Ken’s Distributing supplies replacement diaphragms for commonly used 2 inch and 3 inch diaphragm pumps, as well as additional sizes and configurations. Confirm the pump model and diaphragm specifications before ordering.
Can Buna diaphragms be used for oily wastewater?
Buna is commonly selected for oily wastewater and other applications involving petroleum-based contamination because of its resistance to oils and hydrocarbons. The exact fluid composition and operating conditions should still be reviewed before selecting a diaphragm material.
How do I know when my Buna diaphragm needs replacement?
Common warning signs include reduced pump performance, irregular cycling, leakage, hardening, cracking, bulging, deformation, or visible damage to the diaphragm surface or edges. Inspect the diaphragm whenever pump performance changes unexpectedly.
Can I order Buna replacement diaphragms in bulk?
Yes. Ken’s Distributing offers bulk pricing and blanket order programs for contractors, municipalities, rental companies, and industrial operations that require recurring diaphragm inventory. Contact Ken’s Distributing with your pump information, diaphragm size, and estimated annual quantity for pricing and availability.