Value Collection ZMSCH70312 O-ring Dash 312 Buna-n 70 Duro 50-pack

Product Description

The VALUE COLLECTION ZMSCH70312 is a Dash 312 Buna-N (Nitrile Butadiene Rubber) O-ring designed for sealing applications across HVAC, plumbing, hydraulic, and fluid-handling systems. It measures 0.625 inches inside diameter, 1.0 inch outside diameter, and 0.1875 inches thick with a round cross section. Rated at 70 Shore A hardness, this O-ring delivers firm, reliable compression sealing. The NBR compound is the most widely used O-ring elastomer in the trade, providing excellent resistance to petroleum products, oils, and fuels. Sold in a pack of 50, it is well suited for maintenance operations requiring multiple seal replacements in a single service call.

This O-ring fits sealing grooves dimensioned to the Dash 312 standard per SAE and MIL-Spec classifications. Typical applications include refrigerant service fittings, plumbing shutoff valves, hydraulic couplings, fuel system components, and general fluid-handling assemblies. The Buna-N material is compatible with petroleum-based fluids, making it a common choice for HVAC service ports, compressor fittings, and oil-wetted plumbing connections in both residential and light commercial settings. Licensed technicians in HVAC, plumbing, and fluid power trades reach for this seal as a standard service item.

Key Features

• Buna-N (NBR) compound offers excellent resistance to petroleum products, oils, and fuels
• 70 Shore A hardness rating provides firm compression set and reliable sealing under pressure
• Round cross section conforms to Dash 312 groove dimensions per SAE and MIL-Spec standards
• Operating temperature range of -40 degrees F to 250 degrees F suits most HVAC and plumbing service environments
• Good tear and abrasion resistance extends service life in dynamic and static sealing applications
• Pack of 50 supports high-volume service and stocking needs

Compatibility

Compatible with petroleum products and petroleum-based fluid systems. Conforms to SAE and MIL-Spec O-ring standards for Dash 312 groove dimensions. Not FDA approved; not intended for food-contact or potable-water applications.

Installation Notes

Installation is typically performed by licensed HVAC technicians, plumbers, or fluid-power mechanics. Always relieve system pressure and shut off fluid supply before removing any fitting or valve that retains this seal. Lubricate the O-ring with a compatible fluid or O-ring lubricant before seating to avoid rolling or tearing during assembly. Do not store unused O-rings in direct sunlight or near motors and electrical equipment that may generate ozone, as ozone exposure degrades NBR compound over time.