8-328 BLACK FKM 90D BACK-UP RING

APG stocks the VBU90328, an AS568-328 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 1.85 in (46.99 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 2.27 in (57.66 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

Viton® (FKM) is specified here for long service life in hot, chemically aggressive environments, excellent resistance to compression set and permeation. Expect good resistance to aromatic hydrocarbons, many acids, and chlorinated solvents. Service temperature is rated from -15°F (-26.1°C) through 400°F (204.4°C). Verify compatibility before use with amines or ketones and esters.

Typical settings include chemical processing, high-temperature process equipment, and automotive fuel systems.

VBU90328 ships individually. Unit weight is approximately 2.29 g. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.