8-351 BLACK FKM 90D BACK-UP RING

APG stocks the VBU90351, an AS568-351 black Viton® (FKM) 90 Shore A Back-Up Ring with an inside diameter of 4.725 in (120.02 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.145 in (130.68 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Viton® (FKM) is specified here for outstanding high-temperature capability, excellent resistance to compression set and permeation. It resists many acids, chlorinated solvents, and aggressive chemicals. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C). Verify compatibility before use with ketones and esters or amines.

Common environments for this compound include high-temperature process equipment, oil and gas, and semiconductor equipment.

Order part number VBU90351, sold individually. Nominal inside diameter is listed as 4 3/4 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.