8-374 BLACK FKM 90D BACK-UP RING

APG stocks the VBU90374, an AS568-374 black Viton® (FKM) 90 Shore A Back-Up Ring with an inside diameter of 9.225 in (234.32 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 9.645 in (244.98 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Expect good resistance to many acids, aggressive chemicals, and engine and transmission fluids. Viton® (FKM) is valued for excellent resistance to compression set and permeation, outstanding high-temperature capability. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C). It should not be specified for service in low-molecular-weight organic acids or hot water and steam.

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

This item is sold individually under part number VBU90374. Nominal inside diameter is listed as 9 1/4 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. For a size or compound outside the standard catalog, APG can quote from a print or sample.