8-272 BLACK FKM 90D BACK-UP RING

This back-up ring is supplied in AS568-272 black Viton® (FKM) 90 Shore A built to an inside diameter of 9.484 in (240.89 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 9.762 in (247.95 mm), catalogued under part number VBU90272. It allows a standard o-ring to operate at higher pressures than it could unsupported.

Viton® (FKM) is specified here for excellent resistance to compression set and permeation, industry benchmark where nitrile reaches its thermal limit. The compound resists many acids, petroleum oils and fuels, and engine and transmission fluids. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). It should not be specified for service in hot water and steam or ketones and esters.

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

Stocked as VBU90272 and sold individually. Nominal inside diameter is listed as 9 1/2 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.