8-429 BLACK BUNA 90D BACK-UP RING

The HB90429 is an AS568-429 black Buna-N (Nitrile) 90 Shore A Back-Up Ring supplied with an inside diameter of 4.975 in (126.37 mm), a cross section of 0.275 in (6.99 mm), and an outside diameter of 5.525 in (140.34 mm). This back-up ring extends o-ring service life by supporting the seal against extrusion under high pressure.

This material stands up to many alcohols, propane and butane, and water. Buna-N (Nitrile) is known for strong abrasion and tear resistance, reliable performance in both static and dynamic service. Rated temperature range runs from -40°F (-40°C) to 250°F (121.1°C) in continuous service. Exposure to strong acids or ketones will shorten service life.

Typical settings include general industrial maintenance, construction equipment, and fluid power.

Order part number HB90429, sold individually. Unit weight is approximately 9.0806 g and nominal inside diameter is listed as 5 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing. APG supports cross-referencing from drawings, samples and competitor numbers when a listed size is not an exact fit.