Value Collection ZMSCHB90231 Backup Ring O-ring Nbr

Product Description

The VALUE COLLECTION ZMSCHB90231 is a rectangular cross-section backup ring O-ring made from Nitrile Butadiene Rubber (NBR). It measures 2.631 inches inner diameter by 2.867 inches outer diameter with a thickness of 0.0468 inches (nominal 3/64 inch). Rated at 90 durometer, this extra-hard ring is engineered to prevent O-ring extrusion under pressure in high-load sealing applications. It operates across a temperature range of -40 to 250 degrees F, making it suitable for a wide range of fluid and pneumatic systems. Plumbers, HVAC technicians, and industrial maintenance professionals install backup rings alongside primary O-rings to extend seal life in pressurized assemblies. This part is sold in packages of 25.

This backup ring is used in hydraulic cylinders, pneumatic actuators, fluid fittings, and other dynamic or static sealing applications where standard O-rings require anti-extrusion support. The NBR material provides good resistance to petroleum-based oils, fuels, and many hydraulic fluids, making it a common choice in plumbing, HVAC, and general industrial maintenance. The Dash 8-231 designation corresponds to a standard sizing reference used across trade catalogs and MRO sourcing. Install alongside compatible primary O-rings in grooved gland assemblies requiring rectangular backup ring geometry.

Key Features

• Rectangular cross-section profile designed specifically for backup ring applications to resist O-ring extrusion
• 90 durometer extra-hard NBR construction for high-pressure sealing environments
• 2.631 inches ID x 2.867 inches OD x 0.0468 inches thick — Dash 8-231 standard sizing
• Temperature rated from -40 to 250 degrees F for broad fluid system compatibility
• NBR material offers resistance to petroleum oils, hydraulic fluids, and fuels
• Sold in a package quantity of 25 units

Compatibility

Designed as a standard Dash 8-231 rectangular backup ring for use in gland assemblies requiring a 2.631 inch ID backup ring with rectangular cross-section geometry. Verify groove dimensions and gland design before installation.

Installation Notes

Backup rings are typically installed by plumbers, hydraulic technicians, or industrial maintenance professionals working on pressurized fluid or pneumatic assemblies. Always depressurize and isolate the system before disassembling any gland or fitting. Inspect the gland groove for damage or contamination before seating the backup ring. Do not stretch or twist the ring during installation; use a clean, smooth installation tool to avoid cutting or deforming the sealing surface.