8-149 BLACK BUNA 90D BACK-UP RING

Part number HB90149 is an AS568-149 black Buna-N (Nitrile) 90 Shore A Back-Up Ring with an inside diameter of 2.8 in (71.12 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 3.006 in (76.35 mm). A back-up ring bridges the extrusion gap so the primary seal holds its shape under load.

The material holds up against greases and lubricants, water, and petroleum-based oils. Buna-N (Nitrile) offers strong abrasion and tear resistance, reliable performance in both static and dynamic service. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). It should not be specified for service in strong acids or automotive brake fluid.

You will find this material specified across agricultural equipment, general industrial maintenance, and fluid power.

This item is sold individually under part number HB90149. Unit weight is approximately 0.8218 g and nominal inside diameter is listed as 2 13/16 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.