Ordered as VBU90006, this is an AS568-006 black Viton® (FKM) 90 Shore A Back-Up Ring measuring an inside diameter of 0.114 in (2.9 mm), a cross section of 0.07 in (1.78 mm), and an outside diameter of 0.254 in (6.45 mm). The 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 specified here for long service life in hot, chemically aggressive environments, excellent resistance to compression set and permeation. It resists aromatic hydrocarbons, aggressive chemicals, and many acids. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C).
It sees regular use in aerospace, oil and gas, and automotive fuel systems.
Stocked as VBU90006 and sold individually. Unit weight is approximately 0.0436 g and nominal inside diameter is listed as 1/8 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. For a size or compound outside the standard catalog, APG can quote from a print or sample.
description 8-006 BLACK FKM 90D BACK-UP RING
Actual_CS 0.07 inch (1.78 mm)
Actual_ID 0.114 inch (2.9 mm)
Actual_OD 0.254 inch (6.45 mm)
ProductCode Description O-Rings - Backup Rings