8-323 BLACK BUNA 90D BACK-UP RING

This back-up ring is supplied in AS568-323 black Buna-N (Nitrile) 90 Shore A built to an inside diameter of 1.287 in (32.69 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 1.707 in (43.36 mm), catalogued under part number HB90323. It extends o-ring service life by supporting the seal against extrusion under high pressure.

As a material, Buna-N (Nitrile) is valued for the most widely specified general-purpose sealing elastomer, reliable performance in both static and dynamic service. It resists hydraulic fluids, petroleum-based oils, and water. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). Applications involving ketones or automotive brake fluid call for a different compound.

You will find this material specified across hydraulic and pneumatic systems, construction equipment, and general industrial maintenance.

Stocked as HB90323 and sold individually. Unit weight is approximately 1.256 g and nominal inside diameter is listed as 1 5/16 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. For a size or compound outside the standard catalog, APG can quote from a print or sample.