8-379 BLACK BUNA 90D BACK-UP RING

This back-up ring is supplied in AS568-379 black Buna-N (Nitrile) 90 Shore A with an inside diameter of 10.975 in (278.77 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 11.395 in (289.43 mm), catalogued under part number HB90379. It allows a standard o-ring to operate at higher pressures than it could unsupported.

It resists greases and lubricants, water, and propane and butane. Buna-N (Nitrile) delivers reliable performance in both static and dynamic service, strong abrasion and tear resistance. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Verify compatibility before use with automotive brake fluid or strong acids.

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

Reference part number HB90379 when ordering; the item is sold individually. Unit weight is approximately 9.3825 g. Check the compound against your process media, pressure and temperature before committing to a design. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.