8-372 BLACK FKM 90D BACK-UP RING

Part number VBU90372 is an AS568-372 black Viton® (FKM) 90 Shore A Back-Up Ring supplied with an inside diameter of 8.725 in (221.62 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 9.145 in (232.28 mm). A back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

Viton® (FKM) is specified here for very low compression set at elevated temperature and long service life in hot, chemically aggressive environments. The compound resists aromatic hydrocarbons, chlorinated solvents, and engine and transmission fluids. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C). It should not be specified for service in ketones and esters or low-molecular-weight organic acids.

Common environments for this compound include oil and gas, semiconductor equipment, and automotive fuel systems.

This item is sold individually under part number VBU90372. Unit weight is approximately 9.8067 g and nominal inside diameter is listed as 8 3/4 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.