6226-03 EPDM 70 U-Cup Seal 1/4" ID x 5/8" OD x 3/16" CS

This 70 durometer black EPDM U-Cup is peroxide cured for enhanced durability and compression set resistance. It performs well in environments where moisture, steam, and aggressive chemicals are present, making it a reliable option when petroleum-based materials are not suitable.

If you need a seal that holds pressure, resists water and chemicals, and keeps your system running without leaks, this AN6226 EPDM U-Cup is a solid choice. It is designed to deliver consistent sealing performance while reducing maintenance and downtime in demanding applications.

Operating temperature: -40° to +300°F (–40° to +149°C)

This material maintains flexibility in cold conditions and strength at higher temperatures, helping your equipment perform across a wide range of environments.

Material & Performance Details

Manufactured from high-strength 70 durometer EPDM rubber, this U-Cup is built for long-lasting performance in water-based and chemical environments.

Performance strengths include:

• Excellent resistance to water and steam
• Strong resistance to polar chemicals
• Reliable sealing up to 500 PSI
• Good compression set resistance for longer service life
• Excellent weathering and ozone resistance

Chemical compatibility:

Excellent resistance to:

• Water and steam
• Phosphate esters
• Ketones
• Alcohols
• Alkalis
• Anhydrous ammonia

Limited capability with:

• Mild acids depending on concentration and exposure

Not compatible with:

• Petroleum oils and fuels
• Concentrated sulfuric acid
• Concentrated nitric acid

Sizes & Measurements

• Cross Section (CS): 4.76 mm (0.187 in)
• Inside Diameter (ID): 6.35 mm (0.250 in)
• Outside Diameter (OD): 15.88 mm (0.625 in)
• Part Number: 6226-03
• Standard: AN6226 Series

Applications & Use Cases

This U-Cup is commonly used in hydraulic and pneumatic systems where water, steam, or chemical resistance is required. It performs well in cylinders, valves, pumps, and fluid systems exposed to harsh environments.

Typical industries include:

• Water treatment and processing
• Chemical handling systems
• Industrial equipment
• Air and gas systems
• Applications using phosphate ester fluids

If your system runs in wet or chemical-heavy conditions, this seal helps prevent leaks and keeps your equipment operating efficiently.

Key Specifications

• Material: EPDM (Peroxide Cured)
• Durometer: 70 Shore A
• Color: Black
• Standard: AN6226
• Certifications: UL approved per JOHX2 (water, steam, air, inert gases)
• Temperature Range: -40°F to +300°F (-40°C to +149°C)
• Pressure Rating: Up to 500 PSI

Why Buy from The O-Ring Store LLC

You are not just buying a seal. You are protecting your operation.

• ISO9001:2015 certified for consistent quality and traceability
• USA-based inventory for fast delivery
• Same-day shipping on in-stock items
• Custom sizes available for unique applications
• Full lot traceability and documentation available
• Experienced team ready to support your application
• Competitive pricing without compromising performance

We make getting O-Rings easy and make sure you get the right seal the first time.