Value Collection ZMSCHB90011 Nitrile Backup Ring Dash 8-011

Product Description

The VALUE COLLECTION ZMSCHB90011 is a rectangular cross-section nitrile butadiene rubber (NBR) backup ring designed to prevent O-ring extrusion under pressure. With an inside diameter of 0.327 inches, an outside diameter of 0.433 inches, and a thickness of 0.045 inches (3/64 inches), this Dash 8-011 ring seats alongside a primary O-ring to stabilize the seal in high-load or dynamic applications. Rated at 90 durometer (extra hard), it resists deformation under pressure and maintains its profile from -40 degrees F to 250 degrees F. Plumbers, HVAC technicians, and hydraulic system technicians use backup rings like this to extend seal life in assemblies where gap extrusion is a concern. Sold in packs of 100.

This backup ring is suited for use in fluid handling, pneumatic, and hydraulic sealing assemblies that require a Dash 8-011 dimensional profile. It is appropriate for residential and light commercial plumbing connections, HVAC refrigerant-side fittings, and general industrial hydraulic circuits where NBR is compatible with the working fluid. NBR provides good resistance to petroleum-based oils, fuels, and water. This ring is not FDA approved and should not be used in food-grade or potable-water-contact applications where food-safe material certifications are required.

Key Features

• Rectangular cross-section prevents O-ring extrusion in pressurized assemblies
• 90 durometer extra-hard NBR resists deformation under high-load conditions
• Dash 8-011 sizing: 0.327 inches ID x 0.433 inches OD x 0.045 inches thick
• Operating temperature range of -40 degrees F to 250 degrees F
• Compatible with petroleum-based oils, fuels, and water
• Packaged in quantities of 100 for bench stock and field use

Compatibility

Designed as a standard Dash 8-011 backup ring for use with O-rings of the same dash designation in hydraulic, pneumatic, and fluid sealing assemblies where nitrile butadiene rubber is chemically compatible with the working medium.

Installation Notes

Backup rings are typically installed by plumbers, HVAC technicians, or hydraulic system mechanics during seal replacement or new assembly. Always depressurize and isolate the system before disassembling any fitting or port. Inspect the gland groove for burrs or damage before seating the backup ring, as surface defects can compromise the seal. Place the backup ring on the low-pressure side of the O-ring to properly prevent extrusion.