Patent ID: 8333409

Claim:
A threaded joint having a longitudinal axis, the joint comprising: a threaded pin and a threaded box, the pin being adapted to be made up in the box, the box including an annular groove comprising a groove bottom and first and second sidewalls, the first sidewall longitudinally spaced apart from the second sidewall; and a seal ring having: a generally right circular cylindrical external surface of generally uniform diameter extending between a first base and a second base; an internal surface radially opposite from the external surface, the internal surface comprising a plurality of protruding annular ribs; the first base having at least a portion with a frustoconical shape; and the second base having at least a portion with a frustoconical shape axially opposite to the first base; the first and second bases being slanted such that the external surface is wider than the internal surface; the seal ring being interposed between the pin and the box; wherein the seal ring is uniformly solid from the external surface to the inner surface and wherein the seal ring is uniformly solid from the first base to the second base; the first and second bases of the seal ring being in sealing contact with respective surfaces of the first and second sidewalls of the annular groove in the box; the internal surface of the seal ring configured to sealingly contact an exterior surface of the pin, wherein each and every one of the ribs is configured to sealingly contact the exterior surface of the pin when the seal ring is pressurized against the pin; the external surface of the seal ring extending from the first sidewall to the second sidewall; the first end of the external surface being longitudinally spaced-apart from the second end by a first longitudinal distance when about the same amount of pressure is acting on the external surface and the internal surface, the first end being longitudinally spaced-apart from the second end by a second longitudinal distance when a greater amount of pressure is acting on the external surface than on the internal surface, the first longitudinal distance being greater than the second longitudinal distance; wherein a radial depth of the groove is greater than a radial thickness of the seal ring; the seal ring is pressurized against said pin by a fluid acting solely on said external surface to sealingly contact said exterior surface of the pin; and wherein the entire external surface of the seal ring is radially spaced apart from the groove bottom when the seal ring is not pressurized against the pin.