8-377 BLACK BUNA 90D BACK-UP RING

APG stocks the HB90377, an AS568-377 black Buna-N (Nitrile) 90 Shore A Back-Up Ring built to an inside diameter of 9.975 in (253.37 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 10.395 in (264.03 mm). A back-up ring installs on the low-pressure side of an o-ring to prevent extrusion into the clearance gap at elevated pressure.

Buna-N (Nitrile) is known for the most widely specified general-purpose sealing elastomer and low compression set under sustained load. This material stands up to hydraulic fluids, petroleum-based oils, and greases and lubricants. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Exposure to ketones or strong acids will shorten service life.

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

This item is sold individually under part number HB90377. Unit weight is approximately 8.418 g. Check the compound against your process media, pressure and temperature before committing to a design.