8-219 BLACK FKM 90D BACK-UP RING

VBU90219 is an AS568-219 black Viton® (FKM) 90 Shore A Back-Up Ring with an inside diameter of 1.296 in (32.92 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.574 in (39.98 mm). In service, this back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

It resists aggressive chemicals, engine and transmission fluids, and petroleum oils and fuels. That behavior comes from the compound itself: Viton® (FKM) is widely chosen for very low compression set at elevated temperature and long service life in hot, chemically aggressive environments. Service temperature is rated from -15°F (-26.1°C) through 400°F (204.4°C). It should not be specified for service in hot water and steam or low-molecular-weight organic acids.

Common environments for this compound include automotive fuel systems, chemical processing, and aerospace.

This item is sold individually under part number VBU90219. Unit weight is approximately 0.68 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.