8-475 BLACK FKM 90D BACK-UP RING

Part number VBU90475 is an AS568-475 black Viton® (FKM) 90 Shore A Back-Up Ring with an inside diameter of 25.94 in (658.88 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 26.49 in (672.85 mm). A back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

This material stands up to petroleum oils and fuels, chlorinated solvents, and many acids. That behavior comes from the compound itself: Viton® (FKM) delivers excellent resistance to compression set and permeation, long service life in hot, chemically aggressive environments. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). Verify compatibility before use with low-molecular-weight organic acids or ketones and esters.

You will find this material specified across chemical processing, aerospace, and oil and gas.

VBU90475 ships individually. As always, verify media compatibility and operating conditions against the requirements of your specific application. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.