8-205 BLACK FKM 90D BACK-UP RING

VBU90205 is an AS568-205 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 0.421 in (10.69 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 0.699 in (17.75 mm). In service, this back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

The compound resists many acids, engine and transmission fluids, and petroleum oils and fuels. Viton® (FKM) is widely chosen for very low compression set at elevated temperature and the industry benchmark where nitrile reaches its thermal limit. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service. Applications involving hot water and steam or ketones and esters call for a different compound.

Typical settings include semiconductor equipment, chemical processing, and high-temperature process equipment.

Stocked as VBU90205 and sold 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.