8-269 BLACK BUNA 90D BACK-UP RING

Part number HB90269 is an AS568-269 black Buna-N (Nitrile) 90 Shore A Back-Up Ring built to an inside diameter of 8.734 in (221.84 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 9.012 in (228.9 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

Expect good resistance to propane and butane, hydraulic fluids, and water. Buna-N (Nitrile) delivers an economical choice for high-volume maintenance programs and low compression set under sustained load. Published continuous service range is -40°F (-40°C) to 250°F (121.1°C). It is not the right choice where ketones or strong acids are present.

Common environments for this compound include agricultural equipment, fluid power, and hydraulic and pneumatic systems.

Stocked as HB90269 and sold individually. Unit weight is approximately 3.159 g. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.