8-456 BLACK FKM 90D BACK-UP RING

Part number VBU90456 is an AS568-456 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 13.475 in (342.27 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 14.025 in (356.24 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.

It resists engine and transmission fluids, many acids, and aggressive chemicals. That behavior comes from the compound itself: Viton® (FKM) delivers long service life in hot, chemically aggressive environments and the industry benchmark where nitrile reaches its thermal limit. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C).

It sees regular use in chemical processing, semiconductor equipment, and aerospace.

Stocked as VBU90456 and sold individually. 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.