8-218 BLACK FKM 90D BACK-UP RING

VBU90218 is an AS568-218 black Viton® (FKM) 90 Shore A Back-Up Ring with an inside diameter of 1.234 in (31.34 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 1.512 in (38.4 mm). In service, this back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Viton® (FKM) is specified here for industry benchmark where nitrile reaches its thermal limit, excellent resistance to compression set and permeation. The material holds up against petroleum oils and fuels, engine and transmission fluids, and many acids. Published continuous service range is -15°F (-26.1°C) to 400°F (204.4°C). It should not be specified for service in hot water and steam or amines.

It sees regular use in chemical processing, oil and gas, and automotive fuel systems.

Stocked as VBU90218 and sold individually. Unit weight is approximately 0.6503 g. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.