EPDM O-Rings | Steam, Water & Ozone Resistant Seals

What is an EPDM O-ring?

EPDM (Ethylene Propylene Diene) O-rings excel in hot water, steam, and ozone/UV environments—typical steam o-rings and outdoor seals. They serve as water/steam resistant seals but are not suitable for fuels or mineral oils.

Operating window roughly -55°C to +150°C. Strong against polar media (acids, bases, alcohols) and weathering, weaker against oils/fuels.

Composition & Properties

EPDM O-rings last in polar media and outdoor exposure; they swell in fuels/oils—use NBR/FKM instead.

• Hardness: 50–90 Shore A; common 70/80A balancing flexibility and compression set.
• Mechanical: good elasticity/rebound; ozone/UV resistance superior to NBR/FKM.
• Formulations: food/steam-grade and peroxide-cured EPDM improve heat/cleanliness.

Temperature Range

• Continuous: about -55°C to +150°C (some grades +155~160°C).
• Low-temp: stays flexible near -50°C for cold/outdoor use.
• Steam: suitable for saturated steam/hot water; prolonged superheat prefers steam-grade EPDM/FFKM.

Chemical Compatibility

• Good for: hot water, steam, acids/bases, alcohols, ketones, brake fluid, polar solvents; strong ozone/UV resistance.
• Not for: mineral oils, fuels, lubricants, aliphatic/aromatic hydrocarbons.
• Outdoor: excellent ozone/weathering; ideal for long-term outdoor water-service seals.

Advantages

• Water/steam capable: stable as steam o-rings for cleaning, boilers, and hot water seals.
• Weather/ozone resistant: outperforms NBR/other elastomers outdoors.
• Food-grade options: available for potable water/food contact (confirm lead time).
• Low-temp flexibility: stays elastic for easy installation and sealing in cold climates.

Applications

• HVAC, hot water/steam lines and valves; boilers, steam-clean equipment.
• Water treatment/potable water with chlorine/ozone disinfection (avoid oil contamination).
• Brake fluid/alcohol/polar solvent systems; avoid fuels/mineral oils.
• Outdoor equipment, waterproof fittings needing ozone/UV resistance.

Size Coverage (AS568 / Metric)

• AS568 000–475 available in EPDM; common 70/80A with batch labels.
• Metric/large/custom profiles available; compression/surface finish guidance provided.
• Food/steam grades provided on request.

Ordering & Traceability

• Mixed MOQ 1 across AS568/metric with traceable labels/photos.
• Submit size tables to lock batches and lead times; compression/extrusion guidance included.
• If media includes oils/mixed solvents, share MSDS to avoid incompatibility.

FAQs

• EPDM vs NBR: use NBR/FKM for fuels/oils; use EPDM for water/steam/outdoor.
• Steam? Prolonged superheat needs steam-grade EPDM/FFKM.
• Food/potable water? Use dedicated grades; confirm certification/lead time.
• Outdoor ozone? EPDM is ozone/UV resistant and outlasts NBR outdoors.

Installation & Selection Tips

• Compression: static 15–25%, dynamic 10–20%; lubricate to reduce insertion damage.
• Avoid oil contamination: EPDM swells in oils/fuels—keep storage/assembly oil-free.
• Storage: sealed bags, away from heat/ozone/UV; FIFO to maintain elasticity.