8-276 BLACK FKM 90D BACK-UP RING

Part number VBU90276 is an AS568-276 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 10.984 in (278.99 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 11.262 in (286.05 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

The material holds up against petroleum oils and fuels, aromatic hydrocarbons, and many acids. That behavior comes from the compound itself: Viton® (FKM) delivers long service life in hot, chemically aggressive environments and the industry benchmark where nitrile reaches its thermal limit. Published continuous service range is -15°F (-26.1°C) to 400°F (204.4°C). Applications involving amines or low-molecular-weight organic acids call for a different compound.

Common environments for this compound include automotive fuel systems, oil and gas, and chemical processing.

This item is sold individually under part number VBU90276. Nominal inside diameter is listed as 11 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.