8-258 BLACK FKM 90D BACK-UP RING

Ordered as VBU90258, this is an AS568-258 black Viton® (FKM) 90 Shore A Back-Up Ring with an inside diameter of 5.984 in (151.99 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 6.262 in (159.05 mm). The back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

Viton® (FKM) is valued for outstanding high-temperature capability and the industry benchmark where nitrile reaches its thermal limit. This material stands up to petroleum oils and fuels, aromatic hydrocarbons, and chlorinated solvents. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C).

You will find this material specified across high-temperature process equipment, chemical processing, and semiconductor equipment.

VBU90258 ships individually. Nominal inside diameter is listed as 6 inch. Review your operating media and conditions against this specification before installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.