8-023 BLACK FKM 90D BACK-UP RING

APG stocks the VBU90023, an AS568-023 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 1.051 in (26.7 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 1.191 in (30.25 mm). A back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

Viton® (FKM) is specified here for long service life in hot, chemically aggressive environments and industry benchmark where nitrile reaches its thermal limit. It resists chlorinated solvents, many acids, and petroleum oils and fuels. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service. Exposure to ketones and esters or hot water and steam will shorten service life.

Maintenance and OEM teams specify it across high-temperature process equipment, semiconductor equipment, and chemical processing.

VBU90023 ships individually. Unit weight is approximately 0.3047 g and nominal inside diameter is listed as 1 1/16 inch. Review your operating media and conditions against this specification before installation. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.