Sumitomo Metal Industries, Inc.

Vallourec & Mannesmann Oil & Gas France

Takahiro Hamamoto

Masaaki Sugino

Suguru Yamaguchi

Jean-Francois Charvet-Quemin

Keiichi Nakamura

Eric Verger

Shigeo Nagasaku

Michihiko Iwamoto

Miyuki Yamamoto

Takahiro Takano

Katsutoshi Sumitani

Jean-Pierre Emery

Benoit Le Chevalier

A liquid and gas tight threaded tubular connection includes a first axial abutment surface formed at the free end of an annular lip of a threaded male element and a second axial abutment surface formed at the end of a housing of a threaded female element. The first and second axial abutment surfaces have the same axial half-sections, the inclination of which varies progressively in the radial direction.

Liquid and gas tight threaded tubular connection

A threaded joint for steel pipes comprising a pinhaving a tapered male thread, a tapered sealing surface, and an end shoulder surfaceand a boxhaving correspondingly a tapered female thread, a tapered sealing surface, and a shoulder surfacewhich is capable of easy tightening and has improved air tightness by the sealing surfaces is arranged such that the pin and the box each have a noncontacting region B where the peripheral surfaces of the pin and the box do not contact each other between the sealing surfacesand the shoulder surfacesand. At least a portion of the noncontacting region of the pin adjoining the to end of the pin is a tapered surface portionhaving substantially the same angle of slope as the tapered sealing surface, and the noncontacting region of the box is a substantially cylindrical surface.

Threaded joint for steel pipes

A threaded joint for steel pipes constituted by a pin having male threads and a box having female threads is improved with respect to ease of insertion of the pin and galling resistance of the threaded portions. The stabbing flanks of the threads in a complete thread portion of one of the pin and a box has a two-step stabbing shape having a chamfer. The two-step stabbing shape has a stabbing flank angle &#x3b1; of 5-45&#xb0; and a chamfer angle &#x3b2; of 20-60&#xb0;. The ratio h/H of the chamfer height h to the thread height H of the pin is 0.25-0.50, or the ratio of the cross-sectional area of the chamfered portion to the overall cross-sectional area of the stabbing flank is made at least a value corresponding to a chamfer height ratio h/H of 0.25 and at most a value corresponding to a chamfer height ratio of 0.50.

A tubular threaded joint which has excellent resistance to compression and which permits easy tightening operation in the field in a vertical state comprises a pin having a male threaded zone and a box having a female threaded zone. The pin or the box has an end shoulder surface on its end, and the other member has a shoulder surface which abuts against the end shoulder surface. The screw threads of the male threaded zone and the female threaded zone are trapezoidal threads having a crest, a load flank, and a stabbing flank. The lip length, which is the distance in the axial direction of a member having an end shoulder surface between the end shoulder surface and the closest engaged thread to that surface, is at least 140 times the stabbing flank clearance, which is the distance in the axial direction between the stabbing flanks of the male thread and the female thread when the load flanks of the male and female threads contact each other. The stabbing flank of the male thread is preferably chamfered.

Tubular threaded joint

Growing community of inventors

Wakayama, Japan

Takahiro Hamamoto