8-048 BLACK FKM 90D BACK-UP RING

APG stocks the VBU90048, an AS568-048 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 4.739 in (120.37 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 4.879 in (123.93 mm). A back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

As a material, Viton® (FKM) offers excellent resistance to compression set and permeation, outstanding high-temperature capability. It resists engine and transmission fluids, petroleum oils and fuels, and chlorinated solvents. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service.

Typical settings include semiconductor equipment, aerospace, and oil and gas.

Reference part number VBU90048 when ordering; the item is sold individually. 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.