8-451 BLACK FKM 90D BACK-UP RING

APG stocks the VBU90451, an AS568-451 black Viton® (FKM) 90 Shore A Back-Up Ring supplied with an inside diameter of 10.975 in (278.77 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 11.525 in (292.74 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 petroleum oils and fuels, aggressive chemicals, and many acids. That behavior comes from the compound itself: Viton® (FKM) is widely chosen for long service life in hot, chemically aggressive environments and very low compression set at elevated temperature. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service. It should not be specified for service in amines or low-molecular-weight organic acids.

Common environments for this compound include automotive fuel systems, high-temperature process equipment, and semiconductor equipment.

This item is sold individually under part number VBU90451. As always, verify media compatibility and operating conditions against the requirements of your specific application.