8-344 BLACK FKM 90D BACK-UP RING

APG stocks the VBU90344, an AS568-344 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 3.85 in (97.79 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 4.27 in (108.46 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Viton® (FKM) is specified for excellent resistance to compression set and permeation, outstanding high-temperature capability. The material holds up against aromatic hydrocarbons, many acids, and chlorinated solvents. The material carries a published service range of -15°F (-26.1°C) to 400°F (204.4°C). Verify compatibility before use with ketones and esters or hot water and steam.

You will find this material specified across aerospace, semiconductor equipment, and automotive fuel systems.

This item is sold individually under part number VBU90344. Unit weight is approximately 4.5512 g and nominal inside diameter is listed as 3 7/8 inch. Review your operating media and conditions against this specification before installation.