EPDM Rubber Seals
Wayne Rubber manufactures custom EPDM rubber seals for water and steam systems, HVAC equipment, automotive applications, outdoor environments, and electrical enclosures. Available as compression molded, transfer molded, injection molded, and die-cut profiles — in standard and FDA-compliant EPDM compounds across the full Shore A durometer range.
EPDM Seals vs. EPDM Gaskets
The terms “seal” and “gasket” are sometimes used interchangeably, but they describe different product geometries and functions. A gasket is typically a flat or sheet-cut component placed between two flat mating surfaces — a flange face, a cover plate, or a tank lid — and compressed by bolt load to prevent leakage.
A seal is a molded component designed to create a sealing interface in a specific groove, channel, or housing geometry. Seals are profiled to the exact cross-section required: O-rings, lip seals, face seals, bulb seals, edge trim seals, panel gaskets with specific profiles, and custom molded seals for mechanical assemblies all fall into this category.
EPDM is the preferred material for both forms when the application involves water, steam, outdoor weathering, ozone, or UV exposure. Its chemically saturated backbone gives it exceptional resistance to aging and environmental degradation — properties that make it the dominant sealing compound in HVAC, water infrastructure, automotive body sealing, and outdoor electrical equipment.
If your application requires a flat cut gasket, see our EPDM Rubber Gaskets page. If you need a molded profile, edge seal, or mechanically housed sealing component, you’re in the right place.
EPDM Seal Types Wayne Rubber Manufactures
Wayne Rubber produces EPDM seals across all major seal configurations. The right geometry depends on your hardware design, the pressure and temperature conditions, and whether the seal is static or in limited relative motion.
Compress axially between two parallel surfaces — no clearance gap concern, making them ideal for EPDM where high-pressure extrusion resistance is not the primary requirement. Common in pipe unions, valve bonnets, end caps, and fluid connectors in water and HVAC systems. Available as molded rings, cut profiles, or custom shapes.
EPDM o-rings for static sealing applications involving water, steam, brake fluid, ketones, and aqueous media. Available in all AS568, ISO 3601, Metric, and JIS B2401 standard sizes, as well as custom dimensions. EPDM o-rings are the standard choice for water system fittings, irrigation equipment, and outdoor fluid handling where NBR would degrade. Use the O-Ring Size Search to find your size.
Custom-profiled EPDM seals for electrical enclosures, junction boxes, cabinet doors, and equipment panels requiring IP-rated environmental protection. EPDM’s excellent ozone, UV, and weather resistance makes it the standard compound for outdoor electrical enclosure sealing. Available in solid and sponge (foam) grades depending on closure force available.
Molded EPDM seals for access hatches, inspection doors, equipment covers, and vehicle body openings requiring weather, dust, and water ingress protection. EPDM sponge grades compress under low closure force to conform to irregular surfaces; solid grades provide greater durability and compression set resistance in higher-load applications.
Custom-molded EPDM ring seals for pipe joints, push-fit fittings, and flanged connections in water distribution, irrigation, and HVAC piping systems. EPDM is the AWWA-specified material for potable water pipe seals and is widely specified in municipal water and wastewater infrastructure for its long service life in continuous water contact.
EPDM molded seals for automotive cooling systems, sunroof seals, HVAC unit seals, and body weatherstripping applications. EPDM’s resistance to hot water, ethylene glycol coolant, ozone, and UV makes it the dominant material for non-oil-wetted automotive sealing. For fuel or oil-wetted automotive seals, see our nitrile o-rings or FKM seals.
EPDM Seal Material Specifications
Standard EPDM compound properties for sealing applications. Wayne Rubber formulates EPDM and can supply specialty grades outside these ranges including peroxide-cured grades for superior compression set, FDA-compliant grades for food and water contact, and custom-durometer compounds for specific closure force requirements.
| Property | Standard Value / Range |
|---|---|
| Temperature Range | −65°F to +300°F (−54°C to +149°C) Intermittent to +325°F (+163°C) for peroxide-cured grades |
| Hardness (Durometer) | 40 to 90 Shore A — solid compounds Sponge / foam grades: 10–30 Shore A equivalent (ASTM D1056) |
| Tensile Strength | 1,000 – 2,500 psi (solid grades) |
| Elongation at Break | 200% – 450% |
| Compression Set | Good (sulfur-cured); Excellent (peroxide-cured grades) |
| Color | Black (standard); white and custom colors available in FDA grades |
| ASTM Designation | ASTM D-2000 Class M2BA (solid); ASTM D1056 Class 2 (sponge) |
| FDA Compliance | Available — FDA 21 CFR-compliant EPDM grades for food and potable water contact |
| NSF / AWWA | Available — NSF-61 certified grades for potable water applications upon request |
| Water & Steam Resistance | Excellent |
| Ozone, UV & Weather | Excellent — primary advantage over NBR and CR for outdoor sealing |
| Oil & Fuel Resistance | Poor — not recommended for petroleum-based fluid contact |
| Brake Fluid (Glycol-Based) | Excellent — EPDM is the standard material for glycol-based brake fluid systems |
EPDM is not compatible with petroleum-based oils, fuels, or hydraulic fluids. For sealing applications involving these media, nitrile (NBR) or FKM fluoroelastomer are the appropriate choices. Use the Chemical Resistance Guide to confirm material compatibility with your specific fluid exposure.
Static vs. Dynamic EPDM Sealing
Static EPDM Seals
The large majority of EPDM sealing applications are static. There is no relative motion between the seal and the mating surfaces after assembly. Pipe joint seals, enclosure gaskets, flange seals, and access hatch seals are all static applications. EPDM performs excellently in static service: its low compression set (particularly in peroxide-cured grades) allows it to maintain sealing force over long service intervals without replacing the seal.
For static EPDM o-rings, gland fill should be designed in the 65–85% range and squeeze at 15–30% of cross-section diameter. Use the Gland Calculator to verify your groove dimensions for EPDM’s specific thermal expansion characteristics.
Limited-Motion & Dynamic Considerations
EPDM is not a preferred material for continuous reciprocating dynamic sealing. Its abrasion resistance is inferior to nitrile and its tear strength is moderate. However, EPDM is regularly used in limited-motion applications: access doors that open and close repeatedly, valve seats that cycle, and pipe couplings that accommodate thermal expansion movement.
For true dynamic sealing in water or steam applications — reciprocating stems, rotating shafts, or sliding components — EPDM can be used with appropriate gland geometry and surface finish, but HNBR or specialty EPDM compounds may deliver longer service life in high-cycle applications. Wayne Rubber’s engineering team can evaluate your specific motion requirements and recommend the most appropriate compound and geometry.
EPDM Seal Applications by Industry
EPDM’s combination of water resistance, outdoor durability, and wide temperature range gives it the broadest application footprint of any single sealing material. The industries below represent the core of EPDM seal demand.
EPDM vs. Other Seal Materials
EPDM is the correct specification for water, steam, and outdoor sealing. This comparison helps confirm EPDM is the right choice for your application or identifies when a different compound would perform better.
| Property | EPDM | Nitrile (NBR) | Neoprene (CR) | FKM | Silicone |
|---|---|---|---|---|---|
| Water & Steam | ✓ Excellent | ▶ Fair | ▶ Good | ✗ Poor | ✓ Excellent |
| Petroleum Oils & Fuels | ✗ Poor | ✓ Excellent | ▶ Good | ✓ Excellent | ✗ Poor |
| Ozone & UV | ✓ Excellent | ✗ Poor | ✓ Good | ✓ Excellent | ✓ Excellent |
| Temperature Range | −65 to +300°F | −40 to +250°F | −40 to +250°F | −15 to +400°F | −75 to +450°F |
| Glycol Brake Fluid | ✓ Excellent | ✗ Poor | ▶ Limited | ▶ Good | ▶ Good |
| Compression Set | ✓ Good–Excellent | ▶ Good | ▶ Good | ✓ Good–Excellent | ▶ Good |
| Relative Cost | Low – Medium | Low | Medium | High | Medium – High |
EPDM Seal Manufacturing at Wayne Rubber
Custom EPDM Compounding
Wayne Rubber custom formulates EPDM compounds across sulfur-cured, peroxide-cured, and FDA-compliant grades. Peroxide-cured EPDM delivers significantly better compression set resistance than sulfur-cured grades which are critical for seals that must maintain sealing force over long service intervals. We select the curing system appropriate to your application rather than defaulting to a single standard compound. See the full EPDM material page for details.
Sponge & Solid Compounds
Both solid and sponge (closed-cell foam) EPDM are available. Solid EPDM is used where higher sealing force, durability, and dimensional precision are required. Sponge EPDM is used for lower closure force applications, irregular sealing surfaces, and applications where conformability is more important than dimensional accuracy — common in enclosure and door sealing.
Compression, Transfer & Injection Molding
Custom-profiled EPDM seals are manufactured by compression, transfer, or injection molding depending on geometry, volume, and tolerance requirements. Injection molding provides the tightest dimensional control for precision seal profiles. Compression molding is suited for larger cross-sections and medium-to-high volumes. All molding processes are supported; our engineering team recommends the most cost-effective approach for your part. More on our manufacturing capabilities.
Custom Engineering Support
Wayne Rubber’s engineering team works directly with your designers during the seal development phase reviewing cross-section geometry, specifying the correct EPDM grade, and confirming mating surface requirements before tooling is built. This upstream involvement avoids costly redesigns and accelerates time to production.
Request a Quote for Custom EPDM Rubber Seals
Send us your drawing or describe your application details including fluid exposure, temperature range, pressure, and hardware geometry. Wayne Rubber will recommend the right EPDM grade and manufacturing process.