Value Collection ZMSCHB90137 O-ring Backup Ring Nbr 90D

Product Description

The VALUE COLLECTION ZMSCHB90137 is a rectangular cross-section backup ring used to prevent O-ring extrusion in hydraulic and pneumatic sealing assemblies. Manufactured from Nitrile Butadiene Rubber (NBR), it carries a 90 durometer hardness rating, placing it in the extra-hard category. This hardness makes it well suited for high-pressure applications where standard O-rings require backup support to prevent blowout or deformation. The ring measures 2.81 inches inside diameter and 0.0468 inches thick, conforming to Dash 8-137 designation. Plumbers, hydraulic technicians, and industrial maintenance mechanics install backup rings during seal rebuilds and press-fit assemblies on cylinders, actuators, and valve bodies.

This backup ring is appropriate for residential and commercial plumbing, fluid power systems, and general industrial maintenance applications where NBR compatibility with petroleum-based fluids, water, and common hydraulic oils is required. It performs across a temperature range of -40 degrees F to 250 degrees F, making it suitable for most ambient and mildly elevated-temperature service environments. Sold in a package quantity of 25, it is practical for bench stock and service van inventory.

Key Features

• Rectangular cross-section profile designed to back up standard O-rings and resist extrusion under pressure
• Nitrile Butadiene Rubber (NBR) material offers good resistance to petroleum fluids, hydraulic oils, and water
• 90 durometer extra-hard rating provides firm support in dynamic and static sealing applications
• Dash 8-137 designation for straightforward cross-referencing during seal kit assembly
• Rated from -40 degrees F to 250 degrees F for broad service temperature coverage
• Package quantity of 25 supports bulk restocking and multi-unit service calls

Compatibility

Designed as a standard Dash 8-137 backup ring compatible with hydraulic cylinders, pneumatic actuators, valve bodies, and other assemblies requiring rectangular-profile O-ring backup support in groove configurations sized for 2.81 inches inside diameter seals.

Installation Notes

Installation should be performed by a qualified hydraulic, plumbing, or mechanical technician. Depressurize and isolate the system completely before disassembling any seal gland or cylinder end cap. Inspect the groove and mating surfaces for burrs or scoring before seating the backup ring. Do not stretch or twist the backup ring during installation, as distortion can compromise the sealing performance of the assembly.