Patent ID: 8641100

Claim:
A leak-proof threaded tubular connection comprising: a male element disposed at an end of a first tubular component comprising a male threading; a female element disposed at an end of a second tubular component comprising a female threading corresponding to the male threading; at least one of the male or female elements comprising a lip between a respective threading and a respective free end of the one of the male or female element and the other of the male or female element comprising a recess for the lip, the lip comprising a first zone with a peripheral surface turned towards the other of the male or female element on which a first metallic sealing surface is disposed that is radially interference fitted against a corresponding second metallic sealing surface disposed on the other of the male or female element, the lip comprising a second zone located axially between the first zone and the respective threading along an axis of the tubular connection, and wherein radial stiffness of the second zone is less than that of the first zone and that of a third zone adjacent to the second zone in a direction towards the respective threading, the second zone being radially deformed by a pressure exerted thereon, the second zone includes a peripheral surface that defines an annular groove including a first tapered surface connected to a first cylindrical surface at an end of the first zone, a second cylindrical surface connected to the first tapered surface, and a second tapered surface connected to an end of the second cylindrical surface opposite to an end connected to the first tapered surface, and an angle of inclination of the first tapered surface is less than an angle of inclination of the second tapered surface, the first metallic sealing surface is in one interference point contact with the corresponding second metallic sealing surface, and the one interference point contact is defined by a combination of each single point interference contact formed by each point of a first annular contact line on the first metallic sealing surface and each corresponding point of a second annular contact line on the second metallic sealing surface, and the second cylindrical surface having a minimum thickness a the range of 50% to 90% of a thickness of a portion of the first metallic sealing surface of the first zone in the one interference point contact with the corresponding second metallic sealing surface, and less than 90% of a thickness of a wall of the respective threading.