VBU90329 is an AS568-329 black Viton® (FKM) 90 Shore A Back-Up Ring supplied with an inside diameter of 1.975 in (50.17 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 2.395 in (60.83 mm). In service, this back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
This material stands up to petroleum oils and fuels, many acids, and aromatic hydrocarbons. That behavior comes from the compound itself: Viton® (FKM) is specified for long service life in hot, chemically aggressive environments and very low compression set at elevated temperature. Service temperature is rated from -15°F (-26.1°C) through 400°F (204.4°C).
Common environments for this compound include automotive fuel systems, chemical processing, and oil and gas.
Stocked as VBU90329 and sold individually. Unit weight is approximately 2.467 g and nominal inside diameter is listed as 2 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
description 8-329 BLACK FKM 90D BACK-UP RING
Actual_CS 0.21 inch (5.33 mm)
Actual_ID 1.975 inch (50.17 mm)
Actual_OD 2.395 inch (60.83 mm)
ProductCode Description O-Rings - Backup Rings