8-249 BLACK FKM 90D BACK-UP RING

VBU90249 is an AS568-249 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 4.859 in (123.42 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.137 in (130.48 mm). In service, this back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

As a material, Viton® (FKM) delivers long service life in hot, chemically aggressive environments and outstanding high-temperature capability. The compound resists aromatic hydrocarbons, many acids, and chlorinated solvents. 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 hot water and steam or amines.

Maintenance and OEM teams specify it across high-temperature process equipment, semiconductor equipment, and aerospace.

Order part number VBU90249, sold individually. Unit weight is approximately 2.423 g and nominal inside diameter is listed as 4 7/8 inch. Review your operating media and conditions against this specification before installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.