8-206 BLACK FKM 90D BACK-UP RING

APG stocks the VBU90206, an AS568-206 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 0.484 in (12.29 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 0.762 in (19.35 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

As a material, Viton® (FKM) offers excellent resistance to compression set and permeation, long service life in hot, chemically aggressive environments. Expect good resistance to aggressive chemicals, many acids, and engine and transmission fluids. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). Applications involving ketones and esters or low-molecular-weight organic acids call for a different compound.

Maintenance and OEM teams specify it across automotive fuel systems, semiconductor equipment, and oil and gas.

VBU90206 ships individually. Nominal inside diameter is listed as 1/2 inch. Review your operating media and conditions against this specification before installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.