Value Collection ZMSCE70278 Epdm O-ring Dash 278

Product Description

The VALUE COLLECTION ZMSCE70278 is an EPDM (Ethylene Propylene Diene Monomer) O-ring with a round cross section, sized to the Dash 278 standard. It measures 12 inches inside diameter, 12.25 inches outside diameter, and 0.125 inches thick. With a durometer hardness rating of 70 (Hard), this O-ring provides firm sealing force suitable for demanding fluid environments. EPDM compound offers strong resistance to hot water, steam, and phosphate ester hydraulic fluids, making it a reliable choice for plumbing, HVAC, and industrial sealing applications. Licensed tradespeople and maintenance technicians typically specify this size for large-bore sealing tasks.

This O-ring is suited for use in systems handling hot water, steam, and phosphate ester type hydraulic fluids. It is also noted for excellent resistance to Skydrol-type fluids used in commercial aircraft hydraulic systems, expanding its use into aerospace ground-support and industrial hydraulic applications. The large 12-inch bore size makes it appropriate for pipe flanges, large valve stems, pump housings, and similar equipment found in commercial plumbing, HVAC hydronic systems, and industrial process piping. Each package contains 2 O-rings.

Key Features

• EPDM material rated for service from -65 degrees F to 300 degrees F
• Dash 278 standard sizing: 12 inches ID, 12.25 inches OD, 0.125 inches thick
• 70 durometer hardness (Hard) for firm, reliable sealing under pressure
• Compatible with hot water, steam, and phosphate ester hydraulic fluids
• Excellent resistance to Skydrol fluids used in commercial aircraft hydraulic systems
• Round cross section for consistent groove fit and sealing contact

Compatibility

Compatible with systems and fluids including hot water, steam, and phosphate ester type hydraulic fluids. Designed as an OEM-style replacement O-ring for large-bore plumbing, HVAC hydronic, and industrial hydraulic sealing applications requiring a Dash 278 EPDM ring.

Installation Notes

O-ring installation should be performed by a qualified plumber, pipefitter, or mechanical technician following applicable IPC or ASME guidelines. Shut off and depressurize the system completely before removing the old seal. Inspect the groove and mating surfaces for damage or debris before seating the new O-ring. Avoid twisting or rolling the O-ring during installation, and do not use petroleum-based lubricants with EPDM compound, as they can cause swelling and seal failure.