Patent ID: 7066499

Claim:
Pipe integral near-flush threaded joint comprising: a first pipe wall with an outer diameter (D″) comprising a male element ( 1 ) provided on an external surface portion with a first pair of radially spaced, truncated cone-shaped threaded portions ( 6 , 7 ) with teeth having a trapezoidal profile, said first pair of threaded portions ( 6 , 7 ) being divided by a first annular shoulder ( 5 ′) lying on a plane orthogonal to the pipe axis, and a second pipe wall with an outer diameter (D″) comprising a female element ( 2 ) provided on an internal surface portion with a second pair of radially spaced, truncated cone-shaped threaded portions ( 8 , 9 ), said second pair of threaded portions being divided by a second annular shoulder ( 5 ″) lying on a plane orthogonal to the pipe axis, the first and second pairs of threaded portions ( 6 , 7 , 8 , 9 ) having the same conicity value and being adapted to screw mutually and reversibly one inside the other in order to produce a contact between said first and second annular shoulders ( 5 ′, 5 ″) in an assembled position, the first annular shoulder ( 5 ′) and the second annular shoulder ( 5 ″) having the shape of an annulus, lying on a plane for its entirety without presenting any elevation from the plane, each of said male ( 1 ) and female ( 2 ) elements being provided with two metal-metal sealing surfaces ( 12 ′, 13 ′, 12 ″, 13 ″), respectively placed at each axial end of the first and second pairs of threaded portions ( 6 , 7 , 8 , 9 ), wherein a first one of said respective two metal-metal sealing surfaces ( 12 ′, 13 ′, 12 ″, 13 ″) has a conical shape and a second one has a spherical shape and in that the area of the surfaces of the first and second annular shoulders ( 5 ′, 5 ″) each are equal to or greater than 25% of a cross-section area of said pipe walls lying on a plane orthogonal to the pipe axis and wherein at least one of said male ( 1 ) and female ( 2 ) elements comprises along its entire surface a circumferential cavity ( 14 , 15 ) between one of its respective pairs of threaded portions and the respective annular shoulder ( 5 ′, 5 ″), the circumferential cavity ( 14 , 15 ) being adapted to receive the expansion of any lubricating grease applied to threaded portions of the joint.