Value Collection ZMSCHB90215 Nitrile Backup Ring Dash 8-215

Product Description

The VALUE COLLECTION ZMSCHB90215 is a rectangular cross-section nitrile butadiene rubber (NBR) backup ring designed to prevent O-ring extrusion under pressure in dynamic and static sealing applications. It carries a Dash 8-215 designation, measures 1.78 inches inside diameter with a 0.0468-inch thickness, and is rated at 90 Shore A durometer — an extra-hard hardness grade that holds its form in high-pressure and high-temperature service. The operating temperature range spans -40 degrees F to 250 degrees F, making it suitable for a broad range of fluid and pneumatic systems. Each package contains 50 rings, sold as a set with a minimum order quantity of one package.

This backup ring is used in hydraulic cylinders, pneumatic actuators, valve assemblies, and pump seal glands where standard O-rings require anti-extrusion support. It is appropriate for residential and commercial plumbing, HVAC refrigerant circuitry, pool and water treatment equipment, and general industrial fluid power systems. The NBR compound offers solid resistance to petroleum-based oils, fuels, and many common hydraulic fluids. Installers select backup rings of this type whenever system pressure or clearance gaps would otherwise allow an O-ring to deform or flow into the clearance gap during pressurized operation.

Key Features

• Rectangular cross-section profile provides consistent anti-extrusion support against the O-ring
• 90 Shore A durometer (extra-hard) rating resists deformation under high-pressure cycling
• NBR material offers resistance to petroleum oils, hydraulic fluids, and many common process fluids
• Wide service temperature range of -40 degrees F to 250 degrees F suits demanding thermal environments
• Dash 8-215 designation ensures straightforward cross-reference and replacement sourcing
• Packaged in quantities of 50 for shop stock, fleet service, or production line use

Compatibility

Designed as a standard Dash 8-215 backup ring for use alongside AS568-215 O-rings in hydraulic, pneumatic, and fluid sealing assemblies that require anti-extrusion support. Confirm groove geometry and clearance specifications against your equipment service documentation before installation.

Installation Notes

Backup rings are installed by qualified plumbers, pipefitters, hydraulic technicians, and HVAC service technicians working on sealed fluid or pneumatic systems. Depressurize and isolate the system completely before disassembling any seal gland or fitting. Inspect the groove for burrs, scoring, or contamination before seating the backup ring, and position it on the low-pressure side of the O-ring per the equipment manufacturer's seal stack specification. Do not stretch or nick the ring during installation, as edge damage compromises the anti-extrusion function.