8-348 BLACK FKM 90D BACK-UP RING

Part number VBU90348 is an AS568-348 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 4.35 in (110.49 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 4.77 in (121.16 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Viton® (FKM) offers long service life in hot, chemically aggressive environments and very low compression set at elevated temperature. The material holds up against engine and transmission fluids, aggressive chemicals, and aromatic hydrocarbons. Published continuous service range is -15°F (-26.1°C) to 400°F (204.4°C). Exposure to ketones and esters or amines will shorten service life.

Maintenance and OEM teams specify it across oil and gas, chemical processing, and automotive fuel systems.

This item is sold individually under part number VBU90348. Unit weight is approximately 5.066 g. As always, verify media compatibility and operating conditions against the requirements of your specific application.