8-131 BLACK BUNA 90D BACK-UP RING

APG stocks the HB90131, an AS568-131 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 1.674 in (42.52 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 1.88 in (47.75 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.

The material holds up against petroleum-based oils, propane and butane, and greases and lubricants. Buna-N (Nitrile) is widely chosen for an economical choice for high-volume maintenance programs and low compression set under sustained load. The material carries a published service range of -40°F (-40°C) to 250°F (121.1°C). It should not be specified for service in polar solvents or automotive brake fluid.

You will find this material specified across automotive, general industrial maintenance, and hydraulic and pneumatic systems.

This item is sold individually under part number HB90131. Unit weight is approximately 0.504 g and nominal inside diameter is listed as 1 11/16 inch. Check the compound against your process media, pressure and temperature before committing to a design. For a size or compound outside the standard catalog, APG can quote from a print or sample.