8-371 BLACK FKM 90D BACK-UP RING

Part number VBU90371 is an AS568-371 black Viton® (FKM) 90 Shore A Back-Up Ring with an inside diameter of 8.475 in (215.27 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 8.895 in (225.93 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

It resists petroleum oils and fuels, chlorinated solvents, and engine and transmission fluids. That behavior comes from the compound itself: Viton® (FKM) delivers long service life in hot, chemically aggressive environments and outstanding high-temperature capability. Service temperature is rated from -15°F (-26.1°C) through 400°F (204.4°C). Verify compatibility before use with amines or low-molecular-weight organic acids.

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

Reference part number VBU90371 when ordering; the item is sold individually. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.