Value Collection ZMSCH70442 O-ring Dash 442 Nbr 70A

Product Description

The VALUE COLLECTION ZMSCH70442 is a Dash 442 O-ring manufactured from Nitrile Butadiene Rubber (Buna-N), the most widely used elastomer in sealing applications. It features a 7.25-inch inside diameter, 7.75-inch outside diameter, and a 0.25-inch thickness with a round cross section. Rated at 70 Shore A hardness, this O-ring delivers excellent compression set resistance along with strong tear and abrasion resistance. It is well suited for use in fluid and pneumatic systems where petroleum-based media is present. Licensed HVAC technicians, plumbers, and mechanical service professionals install this part as a replacement or maintenance seal in large-bore fittings and equipment flanges.

This O-ring is designed for applications involving petroleum products, hydraulic fluids, and similar media in residential and commercial mechanical systems. Its operating temperature range of -40 degrees F to 250 degrees F makes it appropriate for a broad range of indoor and outdoor service environments. Typical install scenarios include large-diameter pipe flanges, pump housings, valve bodies, and heat exchanger connections where a Dash 442 size is specified. The package contains 2 O-rings per unit, which supports service kits and back-stock applications. It conforms to SAE and MIL-Spec standards.

Key Features

• Buna-N (Nitrile Butadiene Rubber) construction with excellent resistance to petroleum-based fluids
• Dash 442 standard sizing: 7.25 inches ID, 7.75 inches OD, 0.25 inches thick
• 70 Shore A hardness rating for reliable sealing under compression
• Operating range from -40 degrees F to 250 degrees F
• Round cross section for consistent seating in standard O-ring grooves
• Conforms to SAE and MIL-Spec standards; sold in packages of 2

Compatibility

Designed as a standard Dash 442 replacement O-ring for any application specifying a 7.25-inch ID by 7.75-inch OD by 0.25-inch round cross section Buna-N seal compatible with petroleum products.

Installation Notes

Installation is performed by licensed plumbers, HVAC technicians, or qualified mechanical service professionals. Shut off and depressurize the system completely before removing the old O-ring or seating the replacement. Lightly lubricate the O-ring with a compatible fluid or assembly lubricant before installation to prevent tearing during seating. Do not store Buna-N O-rings in direct sunlight or near motors and electrical equipment that may generate ozone, as this degrades the elastomer over time.