8-166 BLACK FKM 90D BACK-UP RING

Part number VBU90166 is an AS568-166 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 6.737 in (171.12 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 6.943 in (176.35 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 long service life in hot, chemically aggressive environments, excellent resistance to compression set and permeation. Expect good resistance to petroleum oils and fuels, aromatic hydrocarbons, and chlorinated solvents. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C). Applications involving amines or ketones and esters call for a different compound.

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

Stocked as VBU90166 and sold individually. Application requirements vary, so validate compatibility with your process conditions prior to installation.