Value Collection ZMSCHB90247 O-ring Backup Ring Nbr

Product Description

The VALUE COLLECTION ZMSCHB90247 is a rectangular-cross-section backup ring O-ring made from Nitrile Butadiene Rubber (NBR), sized at 4.631 inches inside diameter, 4.867 inches outside diameter, and 0.0468 inches thick. With a 90 durometer hardness rating — classified as extra hard — this ring is built to resist extrusion under pressure in hydraulic and pneumatic sealing applications. It carries a Dash 8-247 designation for standardized sizing reference. The NBR compound provides solid resistance to petroleum-based fluids, making it a dependable choice for fluid system sealing tasks handled by plumbers, hydraulic technicians, and mechanical service professionals.

This backup ring is suited for use in hydraulic cylinders, pneumatic actuators, valve assemblies, and fluid-transfer fittings where a secondary seal or anti-extrusion ring is required. The rectangular cross section seats flush in standard backup ring grooves. The temperature range of -40 to 250 degrees F covers most industrial and mechanical service environments. Each package contains 10 rings, and the minimum order quantity is 1 package. Typical applications include maintenance and rebuild work on fluid power systems in both light industrial and commercial settings.

Key Features

• Rectangular cross section functions as a backup ring to prevent O-ring extrusion under pressure
• 90 durometer extra-hard NBR compound resists deformation and compression set
• Dash 8-247 standard sizing ensures drop-in fit in compatible groove dimensions
• Operating temperature range of -40 to 250 degrees F suits a wide range of service conditions
• NBR material compatible with petroleum-based hydraulic fluids and lubricants
• Packaged in quantities of 10 with a minimum order of 1 package

Compatibility

Designed as a standard Dash 8-247 backup ring for use in hydraulic, pneumatic, and fluid-transfer assemblies requiring a rectangular-cross-section anti-extrusion ring in a 4.631-inch ID groove.

Installation Notes

Installation is performed by qualified hydraulic or mechanical technicians. Always depressurize and lock out the system before disassembling any hydraulic or pneumatic component. Inspect the groove for burrs or damage before seating the ring. Avoid rolling or twisting the ring during installation to prevent damage to the sealing surface.