8-437 BLACK FKM 90D BACK-UP RING

VBU90437 is an AS568-437 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 5.975 in (151.77 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 6.525 in (165.74 mm). In service, this back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

The material holds up against engine and transmission fluids, chlorinated solvents, and many acids. Viton® (FKM) is known for very low compression set at elevated temperature 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). Verify compatibility before use with low-molecular-weight organic acids or ketones and esters.

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

VBU90437 ships individually. Unit weight is approximately 14.559 g. 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.