Ordered as HB90473, this is an AS568-473 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 23.94 in (608.08 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 24.49 in (622.05 mm). The back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.
It resists petroleum-based oils, propane and butane, and hydraulic fluids. Buna-N (Nitrile) is widely chosen for the most widely specified general-purpose sealing elastomer and an economical choice for high-volume maintenance programs. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C).
It sees regular use in agricultural equipment, hydraulic and pneumatic systems, and automotive.
Stocked as HB90473 and sold individually. Nominal inside diameter is listed as 24 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
Description 8-473 BLACK BUNA 90D BACK-UP RING
Actual Cross Section 0.275 inch (6.99 mm)
Actual Inside Diameter 23.94 inch (608.08 mm)
Actual Outside Diameter 24.49 inch (622.05 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings