Value Collection ZMSCHB90225 Nbr O-ring Backup Ring 25-pack

Product Description

The VALUE COLLECTION ZMSCHB90225 is a rectangular-cross-section backup O-ring made from Nitrile Butadiene Rubber (NBR), designed to prevent extrusion and seal failure in pressurized systems. With a 1.897-inch inside diameter, 2.131-inch outside diameter, and 0.0468-inch thickness, this Dash 8-225 backup ring seats behind a primary O-ring to support the seal under dynamic or high-pressure conditions. Rated at 90 durometer, the extra-hard hardness grade resists deformation across a working temperature range of -40 to 250 degrees F. Each package contains 25 rings. Licensed plumbers, HVAC technicians, and hydraulic system technicians typically specify this component in service and assembly work.

This backup ring is suited for use in hydraulic cylinders, pneumatic fittings, valve assemblies, pump housings, and fluid system connections where a primary O-ring requires anti-extrusion support. The NBR material provides solid resistance to petroleum-based oils, fuels, and many common hydraulic fluids, making it a dependable choice for plumbing, HVAC refrigerant circuit hardware, and industrial fluid handling applications. The rectangular cross section locks position against the O-ring groove wall and reduces spiral failure risk under cyclical pressure loads.

Key Features

• Dash 8-225 sizing: 1.897 inches ID x 2.131 inches OD x 0.0468 inches thick
• 90 durometer extra-hard NBR construction resists extrusion under high-pressure cycling
• Rectangular cross section for stable, groove-seated anti-extrusion performance
• Working temperature range of -40 to 250 degrees F covers most HVAC and hydraulic service conditions
• NBR compound offers broad compatibility with petroleum oils, fuels, and common hydraulic fluids
• Sold in a 25-piece package for bench stock and service kit replenishment

Compatibility

Designed as an OEM-style replacement or service-stock backup ring for fluid system assemblies requiring a Dash 8-225 rectangular-section anti-extrusion ring in NBR material.

Installation Notes

Installation should be performed by a licensed plumber, HVAC technician, or hydraulic system technician. Depressurize and isolate the system completely before disassembling any fitting, valve, or cylinder that retains this component. Inspect the O-ring groove for burrs, corrosion, or dimensional damage before seating the backup ring and primary O-ring. Do not stretch the backup ring beyond the groove diameter or use sharp tools that could nick the sealing surfaces.