This back-up ring is supplied in AS568-279 black Viton® (FKM) 90 Shore A built to an inside diameter of 12.984 in (329.79 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 13.262 in (336.85 mm), catalogued under part number VBU90279. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.
Viton® (FKM) is valued for long service life in hot, chemically aggressive environments and very low compression set at elevated temperature. It resists aggressive chemicals, many acids, and aromatic hydrocarbons. Rated temperature range runs from -15°F (-26.1°C) to 400°F (204.4°C) in continuous service.
You will find this material specified across aerospace, oil and gas, and chemical processing.
This item is sold individually under part number VBU90279. Check the compound against your process media, pressure and temperature before committing to a design. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.
description 8-279 BLACK FKM 90D BACK-UP RING
Actual_CS 0.139 inch (3.53 mm)
Actual_ID 12.984 inch (329.79 mm)
Actual_OD 13.262 inch (336.85 mm)
ProductCode Description O-Rings - Backup Rings