Value Collection ZMSCHB90009 O-ring Backup Ring Nbr

Product Description

The VALUE COLLECTION ZMSCHB90009 is a rectangular cross-section backup ring used to prevent O-ring extrusion under pressure in hydraulic and pneumatic sealing applications. It measures 0.234 inches inner diameter by 0.34 inches outer diameter, with a thickness of 0.047 inches. Constructed from Nitrile Butadiene Rubber (NBR) and rated at 90 durometer, this extra-hard backup ring resists deformation and blowout in high-pressure assemblies. It carries a Dash 8-009 designation and is suited for plumbing, HVAC, and fluid-system service work where seal integrity is critical.

This backup ring is used in residential and commercial applications wherever an O-ring must be supported against extrusion into a gap under pressure. Typical install scenarios include hydraulic fittings, pneumatic valve assemblies, fluid-control manifolds, and plumbing connection points. It operates across a wide temperature range of -40 degrees F to 250 degrees F, making it viable in both cold-climate and moderate-heat service environments. The NBR compound provides good resistance to petroleum-based fluids, water, and many common refrigerants.

Key Features

• Rectangular cross-section profile functions as a backup ring to prevent O-ring extrusion
• NBR construction offers resistance to petroleum-based fluids and aqueous media
• 90 durometer extra-hard rating maintains shape under elevated system pressures
• Wide service temperature range from -40 degrees F to 250 degrees F
• Dash 8-009 designation for straightforward cross-referencing to standard seal catalogs
• Sold in a package quantity of 100 pieces

Compatibility

Designed as a standard Dash 8-009 backup ring for use with matching O-ring groove dimensions in hydraulic, pneumatic, plumbing, and fluid-system assemblies requiring an inner diameter of 0.234 inches and an outer diameter of 0.34 inches.

Installation Notes

Installation is typically performed by licensed plumbers, HVAC technicians, or hydraulic system technicians. Always depressurize and isolate the system before disassembling any fitting or valve body. Inspect the groove for burrs or contamination before seating the backup ring and O-ring. Do not twist or overstretch the backup ring during installation, as this can compromise the seal.