Value Collection ZMSCHB90218 O-ring Backup Ring Nbr 90D

Product Description

The VALUE COLLECTION ZMSCHB90218 is a rectangular-cross-section backup O-ring designed to prevent extrusion of primary seals in pressurized hydraulic, pneumatic, and fluid-handling systems. Made from Nitrile Butadiene Rubber (NBR) with a 90 durometer hardness rating, this extra-hard backup ring seats behind a primary O-ring to extend seal life under high-pressure or dynamic load conditions. It measures 1.268 inches inside diameter, 1.5 inches outside diameter, and 0.0468 inches thick. Licensed plumbers, hydraulic technicians, and industrial maintenance professionals typically specify this ring when primary seals show extrusion damage or when operating pressures exceed standard O-ring limits.

This backup ring is suited for residential and commercial fluid-handling assemblies, hydraulic cylinders, pneumatic actuators, and plumbing valve bodies where extrusion resistance is required. The NBR compound performs reliably across a wide temperature range, making it appropriate for both chilled water and moderate-heat process systems. Package quantity is 50 rings per pack with a minimum order quantity of 1 pack, making it practical for stocking service vans or MRO inventory.

Key Features

• Rectangular cross section provides direct backup support behind primary O-ring seals to prevent extrusion
• 90 durometer extra-hard NBR compound resists deformation under elevated system pressures
• Rated for service from -40 degrees F to 250 degrees F, suitable for a broad range of fluid and gas applications
• Dash 8-218 sizing ensures interchangeability with standard O-ring groove designs at this dimension
• Nitrile Butadiene Rubber construction offers good resistance to petroleum-based fluids, oils, and hydraulic media
• Sold in packs of 50 units, convenient for MRO stocking and recurring service calls

Compatibility

Designed as an OEM-style replacement backup ring for standard Dash 8-218 O-ring groove applications in hydraulic, pneumatic, and plumbing assemblies requiring a 1.268-inch ID, 1.5-inch OD rectangular-section seal backup.

Installation Notes

Installation should be performed by a qualified hydraulic technician, licensed plumber, or industrial maintenance professional. Depressurize and lock out the system before disassembling any fitting or valve body. Inspect the mating groove for burrs or scoring that could damage the backup ring or primary seal during installation. Do not use petroleum-based lubricants incompatible with NBR compound; consult fluid compatibility data before selecting a installation lubricant.