8-454 BLACK BUNA 90D BACK-UP RING

APG stocks the HB90454, an AS568-454 black Buna-N (Nitrile) 90 Shore A Back-Up Ring built to an inside diameter of 12.475 in (316.87 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 13.025 in (330.84 mm). A back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

The material holds up against hydraulic fluids, water, and many alcohols. Buna-N (Nitrile) is known for the most widely specified general-purpose sealing elastomer and an economical choice for high-volume maintenance programs. Continuous operating temperature is published at -40°F (-40°C) to 250°F (121.1°C). Applications involving strong acids or ozone and direct sunlight call for a different compound.

Typical settings include construction equipment, agricultural equipment, and fluid power.

Order part number HB90454, sold individually. Unit weight is approximately 22.044 g and nominal inside diameter is listed as 12 1/2 inch. Application requirements vary, so validate compatibility with your process conditions prior to installation. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.