8-378 BLACK FKM 90D BACK-UP RING

The VBU90378 is an AS568-378 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 10.475 in (266.07 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 10.895 in (276.73 mm). This back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

Viton® (FKM) is specified here for excellent resistance to compression set and permeation, very low compression set at elevated temperature. This material stands up to chlorinated solvents, petroleum oils and fuels, and aggressive chemicals. Published continuous service range is -15°F (-26.1°C) to 400°F (204.4°C). It is not the right choice where amines or ketones and esters are present.

Common environments for this compound include semiconductor equipment, high-temperature process equipment, and aerospace.

Stocked as VBU90378 and sold individually. Check the compound against your process media, pressure and temperature before committing to a design. For a size or compound outside the standard catalog, APG can quote from a print or sample.