APG stocks the HB90151, an AS568-151 black Buna-N (Nitrile) 90 Shore A Back-Up Ring built to an inside diameter of 2.987 in (75.87 mm), a cross section of 0.103 in (2.62 mm), and an outside diameter of 3.193 in (81.1 mm). A back-up ring allows a standard o-ring to operate at higher pressures than it could unsupported.
Buna-N (Nitrile) is specified for strong abrasion and tear resistance, the most widely specified general-purpose sealing elastomer. The compound resists propane and butane, petroleum-based oils, and many alcohols. Service temperature is rated from -40°F (-40°C) through 250°F (121.1°C). It should not be specified for service in automotive brake fluid or ketones.
Typical settings include fluid power, automotive, and hydraulic and pneumatic systems.
Order part number HB90151, sold individually. Unit weight is approximately 0.8848 g and nominal inside diameter is listed as 3 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
Description 8-151 BLACK BUNA 90D BACK-UP RING
Actual Cross Section 0.103 inch (2.62 mm)
Actual Inside Diameter 2.987 inch (75.87 mm)
Actual Outside Diameter 3.193 inch (81.1 mm)
Measurement System Imperial
Product Category O-Rings - Backup Rings