Abstract: A threaded connection design having a double ellipse in the thread root for reducing stress fatigue is illustrated in this disclosure. The root groove includes a first portion comprising a first elliptical surface being part of a first ellipse. The root groove further includes a second portion comprising a second elliptical surface, being part of a second ellipse, and the second elliptical surface being joined tangentially at a first end to the first elliptical surface at a junction point that defines the bottom of the root groove. The second elliptical surface is joined tangentially at a second end to the load flank.

Abstract: A threaded connection design having a double ellipse in the thread root for reducing stress fatigue is illustrated in this disclosure. The root groove includes a first portion comprising a first elliptical surface being part of a first ellipse. The root groove further includes a second portion comprising a second elliptical surface, being part of a second ellipse, and the second elliptical surface being joined tangentially at a first end to the first elliptical surface at a junction point that defines the bottom of the root groove. The second elliptical surface is joined tangentially at a second end to the load flank.

Abstract: A threaded connection design having a double ellipse in the thread root for reducing stress fatigue is illustrated in this disclosure. The root groove includes a first portion comprising a first elliptical surface being part of a first ellipse. The root groove further includes a second portion comprising a second elliptical surface, being part of a second ellipse, and the second elliptical surface being joined tangentially at a first end to the first elliptical surface at a junction point that defines the bottom of the root groove. The second elliptical surface is joined tangentially at a second end to the load flank.

Abstract: A threaded connection design having a double ellipse in the thread root for reducing stress fatigue is illustrated in this disclosure. The root groove includes a first portion comprising a first elliptical surface being part of a first ellipse. The root groove further includes a second portion comprising a second elliptical surface, being part of a second ellipse, and the second elliptical surface being joined tangentially at a first end to the first elliptical surface at a junction point that defines the bottom of the root groove. The second elliptical surface is joined tangentially at a second end to the load flank.

Abstract: A threaded tube joint for oil extraction industry has a trapezoidal thread and a toroidal sealing surface (11) placed at its end near the thread and engages, for sealing, a corresponding frusto-conical sealing surface (12) wherein the toroidal sealing surface (11) has a radius Rs value comprised within the range given by the formula E 2 ? Vo ? ( b 2.15 ) 2 ? Rs ? ? · E 2 ? tn n 3 ? OD 2 240 ? ? ? · ? ad 2 ? wt 2 ? ( 1 - ? 2 ) ? [ 3 ? ( 1 - ? 2 ) R n 2 ? tn 2 ] 3 / 4 .

Abstract: Threaded joint for pipes consisting of a male member (1) and a female member (2), which are provided on the outer and inner surfaces respectively with two threading portions presenting a lead-in flank ? such that 10°???25°, an abutment surface (9) being present at the end of said male member for abutment to a corresponding annular abutment surface (10) of the female member. The lead-in flanks of the male (1) and the female (2) members, upon make-up and with unloaded joint leave a gap (in the direction parallel to the axis (21) of the joint) varying from 0.01 to 0.12 mm. The internal and external diameters D3 and D4 (of the pipe portion not involved in the coupling with the female member) of said male member, the inner and outer diameters D1 and D2 of the abutment surface of the female member are linked by the relationship: (D22?D12)/(D42?D32)?0.5.

Abstract: A threaded tube joint for oil extraction industry has a trapezoidal thread and a toroidal sealing surface (11) placed at its end near the thread and engages, for sealing, a corresponding frusto-conical sealing surface (12) wherein the toroidal sealing surface (11) has a radius Rs value comprised within the range given by the formula 1 E 2 ⁢ Vo ⁢ ( b 2.

Abstract: Threaded joint for pipes consisting of a male member (1) and a female member (2), which are provided on the outer and inner surfaces respectively with two threading portions presenting a lead-in flank &bgr; such that 10°≦&bgr;≦25°, an abutment surface (9) being present at the end of said male member for abutment to a corresponding annular abutment surface (10) of the female member. The lead-in flanks of the male (1) and the female (2) members, upon make-up and with unloaded joint leave a gap (in the direction parallel to the axis (21) of the joint) varying from 0.01 to 0.12 mm. The internal and external diameters D3 and D4 (of the pipe portion not involved in the coupling with the female member) of said male member, the inner and outer diameters D1 and D2 of the abutment surface of the female member are linked by the relationship: (D22−D12)/(D42−D32)≧0.5.