8-039 BLACK FKM 90D BACK-UP RING

This back-up ring is supplied in AS568-039 black Viton® (FKM) 90 Shore A measuring an inside diameter of 2.739 in (69.57 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 2.879 in (73.13 mm), catalogued under part number VBU90039. It bridges the extrusion gap so the primary seal holds its shape under load.

Viton® (FKM) is specified here for long service life in hot, chemically aggressive environments and industry benchmark where nitrile reaches its thermal limit. The compound resists many acids, aromatic hydrocarbons, and petroleum oils and fuels. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C).

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

Stocked as VBU90039 and sold individually. Nominal inside diameter is listed as 2 3/4 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.