8-178 BLACK FKM 90D BACK-UP RING

This back-up ring is supplied in AS568-178 black Viton® (FKM) 90 Shore A built to an inside diameter of 9.737 in (247.32 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 9.943 in (252.55 mm), catalogued under part number VBU90178. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

This material stands up to many acids, petroleum oils and fuels, and aromatic hydrocarbons. Viton® (FKM) is specified for outstanding high-temperature capability and very low compression set at elevated temperature. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service. Applications involving ketones and esters or low-molecular-weight organic acids call for a different compound.

Maintenance and OEM teams specify it across automotive fuel systems, chemical processing, and oil and gas.

Order part number VBU90178, sold individually. Check the compound against your process media, pressure and temperature before committing to a design.