8-212 BLACK FKM 90D BACK-UP RING

Part number VBU90212 is an AS568-212 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 0.859 in (21.82 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.137 in (28.88 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Viton® (FKM) is specified here for very low compression set at elevated temperature and long service life in hot, chemically aggressive environments. It resists many acids, aromatic hydrocarbons, and petroleum oils and fuels. Published continuous service range is -15°F (-26.1°C) to 400°F (204.4°C). Applications involving amines or hot water and steam call for a different compound.

It sees regular use in chemical processing, oil and gas, and high-temperature process equipment.

Order part number VBU90212, sold individually. Unit weight is approximately 0.518 g and nominal inside diameter is listed as 7/8 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.