Patent ID: 6905150

Claim:
A threaded joint for pipes, comprising a generally tubular male element ( 1 ) with a nominal external diameter (D) carrying a respective male threading near to one of its ends, comprising teeth ( 1 ′), having each lead-in ( 6 ) and load ( 4 ) flanks, with roots there between and, between said end and said respective thread, a first unthreaded surface ( 12 ) carrying a first sealing surface ( 10 ), and an abutment surface ( 14 ) near its extremity, a generally tubular female element ( 2 ) carrying a respective female threading close to one of its ends, comprising teeth ( 2 ′), having each lead-in ( 5 ) and load ( 3 ) flanks, with roots there between and, between said end and said respective thread, a second sealing surface ( 11 ), complementary to said first sealing surface ( 10 ) of the male element ( 1 ), said male and female threads defining between them, when made-up together, a space to store lubricant, said male ( 1 ) and female ( 2 ) elements defining a common symmetrical axis (A) of the joint, said female element ( 2 ) being further provided with a notch ( 13 ) between said respective female thread and said second sealing surface ( 11 ), of a substantially toroidal shape, constituting a reservoir for the lubricant flowing out of the space between the threads of the female ( 2 ) and male ( 1 ) elements during tightening of the joint, and with an abutment surface ( 15 ) adapted for cooperating with the abutment surface ( 14 ) of the male element, when the male ( 1 ) and female ( 2 ) elements are completely made-up, wherein said notch ( 13 ) has a length (X), measured parallel to the joint axis, between 4 and 10 mm, that it begins at a distance (L) from the abutment surface ( 15 ) of the female element ( 2 ), between 5 and 12 mm, and has a volume, expressed in mm 3 , in absolute value of at least 30 times the numerical value of the nominal external diameter (D), expressed in mm, of said male element ( 1 ), wherein the flank ( 6 ) of the tooth of the thread of the male element ( 1 ) nearest to the first sealing surface ( 10 ) is at a distance greater than or equal to L+X from the abutment surface ( 14 ) of the male element whereby said flank ( 6 ) of the tooth of the thread of the male element ( 1 ) is at most circumferentially aligned with the flank ( 3 ′) nearest to the end of said female element ( 2 ) of said notch when made up, thus leaving the whole volume of the reservoir ( 13 ) available for the lubricant.