8-356 BLACK FKM 90D BACK-UP RING

Part number VBU90356 is an AS568-356 black Viton® (FKM) 90 Shore A Back-Up Ring supplied with an inside diameter of 5.35 in (135.89 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 5.77 in (146.56 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 widely chosen for long service life in hot, chemically aggressive environments and very low compression set at elevated temperature. It resists aromatic hydrocarbons, chlorinated solvents, and engine and transmission fluids. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service. Applications involving hot water and steam or ketones and esters call for a different compound.

You will find this material specified across chemical processing, automotive fuel systems, and high-temperature process equipment.

Reference part number VBU90356 when ordering; the item is sold individually. Nominal inside diameter is listed as 5 3/8 inch. Check the compound against your process media, pressure and temperature before committing to a design.