8-174 BLACK BUNA 90D BACK-UP RING

HB90174 is an AS568-174 black Buna-N (Nitrile) 90 Shore A Back-Up Ring measuring an inside diameter of 8.737 in (221.92 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 8.943 in (227.15 mm). In service, this 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 economical choice for high-volume maintenance programs and most widely specified general-purpose sealing elastomer. It resists hydraulic fluids, petroleum-based oils, and propane and butane. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). It should not be specified for service in ketones or ozone and direct sunlight.

Common environments for this compound include general industrial maintenance, construction equipment, and automotive.

Stocked as HB90174 and sold individually. Unit weight is approximately 2.479 g and nominal inside diameter is listed as 8 3/4 inch. Review your operating media and conditions against this specification before installation. APG can cross-reference from an existing part number, a drawing or a physical sample if this size is not an exact match.