8-321 BLACK BUNA 90D BACK-UP RING

APG stocks the HB90321, an AS568-321 black Buna-N (Nitrile) 90 Shore A Back-Up Ring with an inside diameter of 1.162 in (29.51 mm), a cross section of 0.21 in (5.33 mm), and an outside diameter of 1.582 in (40.18 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

Buna-N (Nitrile) is specified here for most widely specified general-purpose sealing elastomer and economical choice for high-volume maintenance programs. The material holds up against propane and butane, water, and many alcohols. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C).

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

Stocked as HB90321 and sold individually. Unit weight is approximately 1.154 g and nominal inside diameter is listed as 1 3/16 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation.