Value Collection ZMSCH90004 O-ring Dash 004 Nbr 90 Duro

Product Description

The VALUE COLLECTION ZMSCH90004 is a Dash 004 nitrile butadiene rubber (Buna-N) O-ring designed for static and dynamic sealing applications across plumbing, HVAC, and fluid-system service. It measures 0.0781 inches inside diameter, 0.2030 inches outside diameter, and 0.0625 inches thick, with a 90 durometer (extra hard) Shore A hardness rating. The round cross-section profile seats reliably in standard Dash 004 grooves. Rated from -40 degrees F to 250 degrees F, this O-ring handles the temperature range common in residential and light commercial mechanical systems. Licensed tradespeople and experienced service technicians are the primary installers.

This O-ring is suited for sealing against petroleum-based fluids, hydraulic oils, fuels, and similar media. Buna-N is the most widely used elastomer in trade sealing applications because of its strong resistance to petroleum products, good compression set characteristics, and solid tear and abrasion resistance. Typical applications include valve stems, pump shafts, fittings, and fluid-line connections in HVAC, plumbing, and pool equipment service. The part ships in a package quantity of 100 units, making it practical for shop stock or service van inventory.

Key Features

• Buna-N (nitrile butadiene rubber) construction — the industry standard elastomer for petroleum-fluid resistance
• 90 durometer Shore A hardness rated extra hard for high-pressure groove retention
• Operating temperature range: -40 degrees F to 250 degrees F
• Dash 004 designation for drop-in replacement in standard AS568 groove geometry
• Black color, round cross-section — 0.0781 inches ID, 0.2030 inches OD, 0.0625 inches thick
• Meets SAE and MIL-Spec standards

Compatibility

Compatible with petroleum products, hydraulic fluids, and similar mineral-oil-based media. Designed as a standard Dash 004 O-ring replacement for any application requiring an AS568-004 groove-profile seal in Buna-N material. Not recommended for exposure to ozone, direct sunlight during storage, or installation near motors and electrical equipment that generate ozone.

Installation Notes

Installation is typically performed by licensed plumbers, HVAC technicians, or pool and irrigation service technicians. Always relieve system pressure and isolate the fluid supply before disassembling any fitting or valve to replace an O-ring. Lightly lubricate the O-ring with a compatible fluid or O-ring lubricant before seating to reduce the risk of tearing during assembly. Inspect the groove for burrs or corrosion before installation, and confirm groove dimensions match the Dash 004 profile.