Part number VBU90209 is an AS568-209 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 0.671 in (17.04 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 0.949 in (24.1 mm). A back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
As a material, Viton® (FKM) is specified for long service life in hot, chemically aggressive environments and very low compression set at elevated temperature. Expect good resistance to many acids, petroleum oils and fuels, and aromatic hydrocarbons. Service temperature is rated from -15°F (-26.1°C) through 400°F (204.4°C). Applications involving ketones and esters or hot water and steam call for a different compound.
Typical settings include automotive fuel systems, oil and gas, and chemical processing.
Stocked as VBU90209 and sold individually. Review your operating media and conditions against this specification before installation.
Description 8-209 BLACK FKM 90D BACK-UP RING
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 0.671 inch (17.04 mm)
Actual Outside Diameter 0.949 inch (24.1 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings