8-384 BLACK FKM 90D BACK-UP RING

The VBU90384 is an AS568-384 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 14.975 in (380.37 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 15.395 in (391.03 mm). This back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

As a material, Viton® (FKM) is known for excellent resistance to compression set and permeation, the industry benchmark where nitrile reaches its thermal limit. It resists aromatic hydrocarbons, petroleum oils and fuels, and chlorinated solvents. Service temperature is rated from -15°F (-26.1°C) through 400°F (204.4°C). Applications involving ketones and esters or hot water and steam call for a different compound.

It sees regular use in oil and gas, chemical processing, and automotive fuel systems.

This item is sold individually under part number VBU90384. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. 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.