8-447 BLACK BUNA 90D BACK-UP RING

This back-up ring is supplied in AS568-447 black Buna-N (Nitrile) 90 Shore A measuring an inside diameter of 8.975 in (227.97 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 9.525 in (241.94 mm), catalogued under part number HB90447. It installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

As a material, Buna-N (Nitrile) offers low compression set under sustained load, strong abrasion and tear resistance. The compound resists propane and butane, water, and petroleum-based oils. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). Applications involving ozone and direct sunlight or strong acids call for a different compound.

It sees regular use in agricultural equipment, hydraulic and pneumatic systems, and fluid power.

HB90447 ships individually. Unit weight is approximately 15.825 g. Check the compound against your process media, pressure and temperature before committing to a design.