8-260 BLACK FKM 90D BACK-UP RING

APG stocks the vbu90260, an AS568-260 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 6.484 in (164.69 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 6.762 in (171.75 mm). A back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

As a material, Viton® (FKM) is widely chosen for very low compression set at elevated temperature and outstanding high-temperature capability. Expect good resistance to petroleum oils and fuels, chlorinated solvents, and aromatic hydrocarbons. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). Applications involving ketones and esters or low-molecular-weight organic acids call for a different compound.

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

Order part number vbu90260, sold individually. Nominal inside diameter is listed as 6 1/2 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.