8-225 BLACK BUNA 90D BACK-UP RING

Ordered as HB90225, this is an AS568-225 black Buna-N (Nitrile) 90 Shore A Back-Up Ring built to an inside diameter of 1.859 in (47.22 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 2.137 in (54.28 mm). The back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Buna-N (Nitrile) delivers low compression set under sustained load, reliable performance in both static and dynamic service. The material holds up against many alcohols, hydraulic fluids, and water. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. It is not the right choice where polar solvents or strong acids are present.

Typical settings include agricultural equipment, construction equipment, and hydraulic and pneumatic systems.

Order part number HB90225, sold individually. Unit weight is approximately 0.7098 g. Application requirements vary, so validate compatibility with your process conditions prior to 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.