8-318 BLACK FKM 90D BACK-UP RING

The VBU90318 is an AS568-318 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 0.975 in (24.77 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 1.395 in (35.43 mm). This back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported. The catalog record notes: 8-318 Fluoroelastomer 90 B/u Ring.

As a material, Viton® (FKM) is specified for excellent resistance to compression set and permeation, long service life in hot, chemically aggressive environments. It resists petroleum oils and fuels, aromatic hydrocarbons, and aggressive chemicals. Service temperature is rated from -15°F (-26.1°C) through 400°F (204.4°C).

Common environments for this compound include high-temperature process equipment, semiconductor equipment, and automotive fuel systems.

Stocked as VBU90318 and sold individually. Nominal inside diameter is listed as 1 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.