8-145 BLACK FKM 90D BACK-UP RING

VBU90145 is an AS568-145 black Viton® (FKM) 90 Shore A Back-Up Ring with an inside diameter of 2.55 in (64.77 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 2.756 in (70 mm). In service, this back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

As a material, Viton® (FKM) is widely chosen for the industry benchmark where nitrile reaches its thermal limit and long service life in hot, chemically aggressive environments. This material stands up to engine and transmission fluids, chlorinated solvents, and many acids. 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 hot water and steam or ketones and esters.

Maintenance and OEM teams specify it across chemical processing, semiconductor equipment, and automotive fuel systems.

VBU90145 ships individually. Unit weight is approximately 1.016 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.