8-470 BLACK FKM 90D BACK-UP RING

APG stocks the VBU90470, an AS568-470 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 20.955 in (532.26 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 21.505 in (546.23 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Expect good resistance to aromatic hydrocarbons, engine and transmission fluids, and chlorinated solvents. Viton® (FKM) is known for outstanding high-temperature capability, excellent resistance to compression set and permeation. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service. It is not the right choice where amines or low-molecular-weight organic acids are present.

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

Order part number VBU90470, sold individually. Nominal inside diameter is listed as 21 inch. Check the compound against your process media, pressure and temperature before committing to a design.