Value Collection ZMSCHB90338 O-ring Dash 8-338 Nbr 90 Duro

Product Description

The VALUE COLLECTION ZMSCHB90338 is a rectangular cross-section backup ring O-ring manufactured from Nitrile Butadiene Rubber (NBR). It measures 3.143 inches inner diameter by 3.509 inches outer diameter with a thickness of 0.0625 inches, conforming to Dash Number 8-338. Rated at 90 durometer, this extra-hard ring is designed to prevent extrusion in high-pressure sealing applications. It handles a working temperature range of -40 to 250 degrees F, making it suitable for a broad range of fluid and pneumatic service conditions. Plumbers, millwrights, and industrial maintenance technicians are the primary installers of this sealing component.

This backup ring is used in hydraulic cylinders, pneumatic actuators, pumps, valves, and general fluid-handling assemblies where standard O-rings require anti-extrusion support. The rectangular cross section seats into standard gland grooves alongside a primary O-ring to eliminate gap extrusion under elevated pressure. Typical applications include industrial maintenance, fluid power systems, and plumbing assemblies requiring reliable sealing across a wide temperature envelope. Each package contains 10 rings, sold with a minimum order quantity of 1 package.

Key Features

• Rectangular cross section functions as a backup ring to prevent O-ring extrusion under pressure
• 90 durometer extra-hard NBR construction resists deformation in high-pressure gland assemblies
• Operating range of -40 to 250 degrees F suits refrigerants, hydraulic fluids, oils, and water service
• Dash 8-338 sizing conforms to standard O-ring groove dimensions for drop-in replacement
• Package quantity of 10 rings supports stocking for maintenance and service kits

Compatibility

Designed as a standard Dash 8-338 backup ring for use in hydraulic, pneumatic, and fluid-sealing gland assemblies that accept rectangular cross-section anti-extrusion rings alongside a primary O-ring.

Installation Notes

Installation should be performed by a qualified mechanic, plumber, or fluid-power technician. Depressurize and isolate the system completely before disassembling any gland or fitting. Inspect the gland groove for burrs or damage before seating the backup ring; a damaged groove will compromise the seal. Lubricate the ring with a fluid compatible with NBR before assembly to avoid tearing during installation.