Threaded connection for pipe

A threaded connection for pipe, including a tubular pin and a tubular box, the pin and the box being adapted to be made up as the pin is screwed into the box,

• wherein the pin includes a male thread having an inner thread portion and an outer thread portion spaced apart from each other in an axial direction, and an intermediate shoulder surface provided between the inner thread portion and the outer thread portion of the male thread,
• the box includes a female thread having an inner thread portion adapted to be engaged by the inner thread portion of the male thread when the connection is made up and an outer thread portion adapted to be engaged by the outer thread portion of the male thread when the connection is made up, and an intermediate shoulder surface provided between the inner thread portion and the outer thread portion of the female thread and adapted to be in contact with the intermediate shoulder surface of the pin when the connection is made up,
• the male thread and the female thread are constructed in such a manner that, upon completion of make-up, load flanks of the male thread and the female thread are in contact with each other and a clearance is formed between stab flanks of the male thread and the female thread,
• the clearance formed between the stab flanks of the male thread and the female thread upon completion of make-up is of such a size that, when a predetermined axial compressive load smaller than a yield compressive load of the pin and the box is applied, the pin and the box deform in such a manner that the stab flanks of the male thread and the female thread start to be in contact so as to bear part of the axial compressive load, and
• the threaded connection for pipe satisfies the following expression:
• G≤0.12+Dsh×tan1°,
• where G, in millimeters, is the dimension of the clearance formed between the stab flanks of the male thread and the female thread upon completion of make-up as measured in the pipe-axis direction, and Dsh, in millimeters, is the distance between a radially outer edge of the intermediate shoulder surface of the pin and a radially inner edge of the intermediate shoulder surface of the box as appearing in a longitudinal cross section upon completion of make-up,
• wherein G≥0.07 mm is satisfied, and
• wherein an axial distance between the location at which the contact between the stab flanks of the inner thread portions starts, due to the application of the predetermined axial compressive load, and the intermediate shoulder surfaces is 0.8 to 1.2 times an axial distance between the location at which the contact between the stab flanks of the outer thread portions starts due to the application of the predetermined axial compressive load and the intermediate shoulder surfaces.