8-245 BLACK FKM 90D BACK-UP RING

This back-up ring is supplied in AS568-245 black Viton® (FKM) 90 Shore A with an inside diameter of 4.359 in (110.72 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 4.637 in (117.78 mm), catalogued under part number VBU90245. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

It resists chlorinated solvents, petroleum oils and fuels, and many acids. Viton® (FKM) is known for outstanding high-temperature capability and long service life in hot, chemically aggressive environments. 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 ketones and esters are present.

You will find this material specified across high-temperature process equipment, automotive fuel systems, and oil and gas.

VBU90245 ships individually. Unit weight is approximately 2.2252 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.