568-251 HSN90 DURO ORINGS

Ordered as HSN90251, this is an AS568-251 green HNBR (Hydrogenated Nitrile) 90 Shore A O-Ring supplied with an inside diameter of 5.109 in (129.77 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 5.387 in (136.83 mm). The o-ring creates a positive seal at flange, piston and rod interfaces without added hardware.

This material stands up to sour gas and amine inhibitors, heat and oxidation, and ozone and weathering. That behavior comes from the compound itself: HNBR (Hydrogenated Nitrile) is known for strong resistance to rapid gas decompression and the oil resistance of nitrile with substantially better heat capability. The material carries a published service range of -40°F (-40°C) to 325°F (162.8°C).

Maintenance and OEM teams specify it across heavy-duty powertrain, commercial refrigeration, and oilfield and downhole equipment.

Stocked as HSN90251 and sold individually. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.