8-266 BLACK FKM 90D BACK-UP RING

This back-up ring is supplied in AS568-266 black Viton® (FKM) 90 Shore A built to an inside diameter of 7.984 in (202.79 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 8.262 in (209.85 mm), catalogued under part number VBU90266. It bridges the extrusion gap so the primary seal holds its shape under load.

The compound resists petroleum oils and fuels, aggressive chemicals, and engine and transmission fluids. Viton® (FKM) is widely chosen for very low compression set at elevated temperature and outstanding high-temperature capability. Published continuous service range is -15°F (-26.1°C) to 400°F (204.4°C). Exposure to hot water and steam or ketones and esters will shorten service life.

Common environments for this compound include aerospace, semiconductor equipment, and automotive fuel systems.

Order part number VBU90266, sold individually. Nominal inside diameter is listed as 8 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. 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.