8-050 BLACK FKM 90D BACK-UP RING

The VBU90050 is an AS568-050 black Viton® (FKM) 90 Shore A Back-Up Ring supplied with an inside diameter of 5.239 in (133.07 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 5.379 in (136.63 mm). This back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

The material holds up against aromatic hydrocarbons, many acids, and chlorinated solvents. Viton® (FKM) is valued for outstanding high-temperature capability and very low compression set at elevated temperature. Published continuous service range is -15°F (-26.1°C) to 400°F (204.4°C). Applications involving ketones and esters or hot water and steam call for a different compound.

Typical settings include aerospace, chemical processing, and oil and gas.

Order part number VBU90050, sold individually. Nominal inside diameter is listed as 5 1/4 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.