VBU90268 is an AS568-268 black Viton® (FKM) 90 Shore A Back-Up Ring supplied with an inside diameter of 8.484 in (215.49 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 8.762 in (222.55 mm). In service, 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) is known for very low compression set at elevated temperature, excellent resistance to compression set and permeation. The material holds up against aromatic hydrocarbons, aggressive chemicals, and engine and transmission fluids. Continuous operating temperature is published at -15°F (-26.1°C) to 400°F (204.4°C). It is not the right choice where amines or ketones and esters are present.
Typical settings include automotive fuel systems, high-temperature process equipment, and aerospace.
VBU90268 ships individually. Nominal inside diameter is listed as 8 1/2 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. Not finding the exact configuration you need? APG cross-references from prints, samples and competitor part numbers.
description 8-268 BLACK FKM 90D BACK-UP RING
Actual_CS 0.139 inch (3.53 mm)
Actual_ID 8.484 inch (215.49 mm)
Actual_OD 8.762 inch (222.55 mm)
ProductCode Description O-Rings - Backup Rings