The VBU90005 is an AS568-005 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 0.101 in (2.57 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 0.241 in (6.12 mm). This back-up ring bridges the extrusion gap so the primary seal holds its shape under load.
Viton® (FKM) is specified here for very low compression set at elevated temperature and industry benchmark where nitrile reaches its thermal limit. The material holds up against engine and transmission fluids, aggressive chemicals, and petroleum oils and fuels. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service. Exposure to ketones and esters or hot water and steam will shorten service life.
Typical settings include semiconductor equipment, automotive fuel systems, and aerospace.
Reference part number VBU90005 when ordering; the item is sold individually. Nominal inside diameter is listed as 3/32 inch. Check the compound against your process media, pressure and temperature before committing to a design. For a size or compound outside the standard catalog, APG can quote from a print or sample.
description 8-005 BLACK FKM 90D BACK-UP RING
Actual_CS 0.07 inch (1.78 mm)
Actual_ID 0.101 inch (2.57 mm)
Actual_OD 0.241 inch (6.12 mm)
ProductCode Description O-Rings - Backup Rings