Value Collection ZMSCH70172 O-ring Dash 172 Nitrile Nbr

Product Description

The VALUE COLLECTION ZMSCH70172 is a Dash 172 nitrile butadiene rubber (Buna-N) O-ring used to create reliable static or dynamic seals in fluid and pneumatic systems. It measures 8.25 inches inside diameter, 8.438 inches outside diameter, and 0.0937 inches thick with a round cross section. Rated for a hardness of 70 Shore A, this O-ring delivers strong compression set resistance along with excellent tear and abrasion resistance. Its Buna-N compound is the most widely used O-ring elastomer and offers proven performance with petroleum-based fluids. Licensed plumbers, pipefitters, mechanics, and industrial maintenance technicians commonly install this size in larger-diameter fittings, flanges, and hydraulic or pneumatic assemblies.

This O-ring is suited for residential and commercial applications where sealing against petroleum products, oils, fuels, and hydraulic fluids is required. The Dash 172 designation follows standard AS568 sizing, making it straightforward to source and replace in the field. Typical install environments include industrial pumps, compressors, large-bore plumbing connections, and HVAC equipment with oil-lubricated components. It is rated for continuous operation from -40 degrees F to 250 degrees F, making it appropriate for a wide range of service conditions.

Key Features

• Buna-N (Nitrile Butadiene Rubber) compound — the most widely used O-ring elastomer for petroleum service
• Excellent resistance to petroleum products, oils, and hydraulic fluids
• Round cross section with strong compression set and tear and abrasion resistance
• Wide operating temperature range: -40 degrees F to 250 degrees F
• Hardness rated at 70 Shore A for a reliable, consistent seal
• Conforms to SAE and MIL-Spec standards
• Store away from direct sunlight, ozone sources, and electrical equipment to preserve elastomer integrity

Compatibility

Designed as a standard Dash 172 replacement O-ring compatible with petroleum products and petroleum-based hydraulic fluids per SAE and MIL-Spec standards. Not recommended for use with ozone-generating environments or applications requiring FDA-approved materials.

Installation Notes

Installation is typically performed by licensed plumbers, pipefitters, or industrial maintenance technicians. Always depressurize and drain the system before replacing O-rings, and shut off all fluid supply valves upstream of the fitting. Lightly lubricate the O-ring with a compatible petroleum-based or system-appropriate lubricant before seating to prevent rolling or tearing during assembly. Do not overstretch the O-ring during installation, and inspect the groove for nicks or burrs that could compromise the seal.