8-251 BLACK BUNA 90D BACK-UP RING

The HB90251 is an AS568-251 black Buna-N (Nitrile) 90 Shore A Back-Up Ring with an inside diameter of 5.109 in (129.77 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.387 in (136.83 mm). This back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

As a material, Buna-N (Nitrile) delivers an economical choice for high-volume maintenance programs and low compression set under sustained load. The material holds up against many alcohols, propane and butane, and hydraulic fluids. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C).

Common environments for this compound include general industrial maintenance, hydraulic and pneumatic systems, and construction equipment.

This item is sold individually under part number HB90251. Unit weight is approximately 1.8969 g. As always, verify media compatibility and operating conditions against the requirements of your specific application.