8-273 BLACK FKM 90D BACK-UP RING

The VBU90273 is an AS568-273 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 9.734 in (247.24 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 10.012 in (254.3 mm). This back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

The material holds up against engine and transmission fluids, aromatic hydrocarbons, and aggressive chemicals. Viton® (FKM) is valued for outstanding high-temperature capability and very low compression set at elevated temperature. Service temperature is rated from -15°F (-26.1°C) through 400°F (204.4°C). It should not be specified for service in amines or hot water and steam.

Maintenance and OEM teams specify it across aerospace, chemical processing, and automotive fuel systems.

VBU90273 ships individually. Nominal inside diameter is listed as 9 3/4 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.