Value Collection ZMSCHB90112 O-ring Backup Ring Nbr Dash 8-112

Product Description

The VALUE COLLECTION ZMSCHB90112 is a rectangular-cross-section backup O-ring rated at 90 durometer, manufactured from Nitrile Butadiene Rubber (NBR). It measures 0.515 inches inner diameter, 0.688 inches outer diameter, and 0.047 inches thick. Backup rings are used alongside primary O-rings in dynamic and static sealing assemblies to prevent extrusion under pressure. Rated for service from -40 degrees F to 250 degrees F, this part suits hydraulic, pneumatic, and fluid-handling systems. It is installed by licensed plumbers, HVAC technicians, and millwrights performing seal maintenance on valves, cylinders, and fittings.

This backup ring is appropriate for residential and commercial sealing applications involving hydraulic lines, pneumatic cylinders, valve stems, and threaded fittings. The Dash 8-112 designation is a standard sizing reference used across fluid power and plumbing assemblies. Its NBR compound provides reliable resistance to petroleum-based oils, fuels, and water-based fluids, making it a common choice in HVAC refrigerant-side accessories, plumbing shutoffs, and general mechanical service. Sold in a package quantity of 100 units, it is suited for shop stock and service van inventory.

Key Features

• NBR compound resists petroleum oils, fuels, and water-based hydraulic fluids
• 90 durometer extra-hard rating reduces extrusion in high-pressure applications
• Rectangular cross section functions as a backup ring to support primary O-ring seals
• Wide service temperature range: -40 degrees F to 250 degrees F
• Dash 8-112 standard sizing for cross-reference and replacement fitment
• Package quantity of 100 supports shop stock and bulk service use

Compatibility

Designed as a standard Dash 8-112 backup ring for use in hydraulic, pneumatic, and fluid-handling sealing assemblies requiring a rectangular-profile NBR ring at 0.515 inches ID by 0.688 inches OD.

Installation Notes

Installation is performed by licensed plumbers, HVAC technicians, or hydraulic system technicians. Depressurize and de-energize the system fully before disassembling any seal or fitting. Use appropriate O-ring installation tools to avoid nicking or stretching the ring during seating. Inspect the gland and mating surfaces for wear or scoring before installing a new backup ring.