8-431 BLACK FKM 90D BACK-UP RING

VBU90431 is an AS568-431 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 5.225 in (132.72 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 5.775 in (146.69 mm). In service, this back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

It resists aggressive chemicals, chlorinated solvents, and engine and transmission fluids. Viton® (FKM) delivers very low compression set at elevated temperature and the industry benchmark where nitrile reaches its thermal limit. Service temperature is rated from -15°F (-26.1°C) through 400°F (204.4°C). It is not the right choice where ketones and esters or low-molecular-weight organic acids are present.

It sees regular use in chemical processing, high-temperature process equipment, and semiconductor equipment.

Reference part number VBU90431 when ordering; the item is sold individually. Unit weight is approximately 12.808 g and nominal inside diameter is listed as 5 1/4 inch. Review your operating media and conditions against this specification before installation.