8-372 BLACK BUNA 90D BACK-UP RING

APG stocks the HB90372, an AS568-372 black Buna-N (Nitrile) 90 Shore A Back-Up Ring with an inside diameter of 8.725 in (221.62 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 9.145 in (232.28 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 specified here for most widely specified general-purpose sealing elastomer, strong abrasion and tear resistance. This material stands up to hydraulic fluids, petroleum-based oils, and greases and lubricants. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). It should not be specified for service in ozone and direct sunlight or strong acids.

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

This item is sold individually under part number HB90372. Unit weight is approximately 7.34 g. Review your operating media and conditions against this specification before installation. If you need a size, durometer or compound that is not listed, APG can cross-reference from a print, a sample or a competitor part number.