The VBU90046 is an AS568-046 black Viton® (FKM) 90 Shore A Back-Up Ring built to an inside diameter of 4.239 in (107.67 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 4.379 in (111.23 mm). This 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) offers long service life in hot, chemically aggressive environments and very low compression set at elevated temperature. The material holds up against engine and transmission fluids, petroleum oils and fuels, and aggressive chemicals. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C). Applications involving low-molecular-weight organic acids or hot water and steam call for a different compound.
You will find this material specified across oil and gas, high-temperature process equipment, and chemical processing.
Order part number VBU90046, sold individually. Nominal inside diameter is listed as 4 1/4 inch. As always, verify media compatibility and operating conditions against the requirements of your specific application.
description 8-046 BLACK FKM 90D BACK-UP RING
Actual_CS 0.07 inch (1.78 mm)
Actual_ID 4.239 inch (107.67 mm)
Actual_OD 4.379 inch (111.23 mm)
ProductCode Description O-Rings - Backup Rings