EPDM O-Rings for Water & Plumbing
Saturated elastomer seals for chlorine, hot water and outdoor plumbing — pool pumps, faucets, filter housings and hose fittings.
EPDM (ethylene propylene diene monomer) is the correct default for water, steam and chlorine exposure because its saturated polymer backbone resists polar media that destroy NBR. For potable water, pool equipment, plumbing fixtures and outdoor hose connections, EPDM outperforms NBR in longevity and dimensional stability — and costs less than silicone for most plumbing service.
Where EPDM seals water systems
- Pool and spa pumps, filters and chlorinators — chlorine and bromine at elevated water temperature
- Faucet cartridges, shower heads and hose bibbs — potable cold and hot water
- Whole-house and RO filter housings — static crush seals on filter bowls
- Garden hose and quick-connect fittings — outdoor UV and ozone exposure
Do not use NBR in sustained chlorine contact — NBR hardens and cracks within weeks in chlorinated pool water. Do not use standard NBR on hot water above +80°C when EPDM or VMQ is available.
For food-processing water lines requiring FDA 21 CFR compliance, confirm NSF-61 or WRAS certification on the compound. VMQ silicone is an alternative for extreme temperature swings but EPDM is preferred when chlorine or ozone resistance is primary.
Related guides: pool & spa O-rings, faucet & plumbing, water filter housings, water treatment. Material overview: EPDM product page.
Why EPDM for This Application
Chlorine & bromine resistance
EPDM survives continuous chlorinated pool and spa water where NBR fails — the standard for pump lids, filter o-rings and chlorinator seals.
Hot water service
Continuous hot water to +150°C — suitable for domestic hot water plumbing, water heaters and commercial dishwashers.
Outdoor durability
Excellent ozone and UV resistance for garden hoses, irrigation and exterior plumbing exposed to weather.
Potable water grades
NSF-61 and WRAS-compliant compounds available for drinking water contact on request with batch traceability.
Common Sizes
| Size | Typical Use |
|---|---|
| AS568 -006 to -012 (1.78 mm CS) | Faucet cartridges, small filter caps and shower connectors |
| AS568 -113 to -120 (2.62 mm CS) | Pool pump lid seals and standard filter housing o-rings |
| AS568 -214 to -222 (3.53 mm CS) | Large pool filter bowls and commercial water treatment housings |
| Big Blue 10"/20" filter gaskets | Whole-house filter housing — flat or o-ring profile depending on brand |
| Metric custom | European faucet and plumbing OEM sizes — quote ID × CS |
Related Application Guides
FAQ
EPDM or silicone for pool pump o-rings?
EPDM is preferred for chlorinated pool water — lower cost and excellent chlorine resistance. VMQ silicone works but is typically reserved for extreme temperature or food-grade requirements.
Can EPDM contact petroleum grease?
No. Petroleum-based lubricants and oils cause severe EPDM swell. Use silicone grease only when lubricating EPDM plumbing and pool seals during installation.
Is EPDM safe for drinking water?
EPDM compounds certified to NSF-61 or WRAS are suitable for potable water contact. Specify drinking water grade when ordering — standard industrial EPDM may not carry these certifications.
EPDM vs NBR for outdoor hose fittings?
EPDM wins on ozone and UV resistance for outdoor service. NBR is acceptable for occasional indoor hose connections but will crack outdoors within 1–2 years.
What hardness for plumbing crush seals?
EPDM 70 Shore A is standard for filter housing and faucet crush seals. Softer 60 Shore A improves sealing on rough or cast surfaces at lower bolt load.
Do you stock common pool filter o-ring sizes?
Yes. Popular AS568 sizes for Hayward, Pentair and Sta-Rite pump and filter models are stocked. Send a photo or model number if unsure — we match from our cross-reference database.
Order EPDM water & plumbing O-rings
Tell us the application (pool, faucet, filter), water temperature and whether NSF/WRAS certification is required. MOQ 1 piece; stocked sizes ship in 3–5 days.