Sumitomo Metal Industries, Inc.

Vallourec & Mannesmann Oil & Gas France

Other

Miyuki Yamamoto

Masaaki Sugino

Shigeo Nagasaku

Michihiko Iwamoto

Kunio Kondo

Eric Verger

Takashi Takano

Kenichi Beppu

Keisuke Hitoshio

Susumu Hirano

Hidetoshi Kurata

Jun Maeda

Gabriel Roussie

Emmanuel Varenne

Takahiro Hamamoto

Pierre Dutilleul

Katsutoshi Sumitani

Celine Sches

Akira Narita

Jean-Francois Charvet-Quemin

Benoit Le Chevalier

A threaded joint for steel pipes comprises a pin () and a box (). The pin has male thread (), a sealing surface (), and a shoulder surface () located on the end face of the pin. Correspondingly, the box has female thread (), a sealing surface (), and a shoulder surface () which can mate or contact with the corresponding portions of the pin. The shoulder surface () of the pin () is provided at an end face of the pin. The sealing surface () of the pin () is located on a pipe end side near the male thread (). A a nose portion () is provided on the pin () between the sealing surface () and the shoulder surface (), the nose portion () being not in contact with a corresponding portion of the box ().

Threaded joint for steel pipes

In order to manufacture a steel pipe for an air bag which can cope with increase in the pressure of gas blown into an air bag and decreases in the wall thickness of an accumulator, a steel having a composition, mass %, of:

High strength steel pipe for an air bag

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

In a threaded joint for steel pipes which are connected by threaded engagement of a pin member having a tapered male thread, a metal seal-forming portion, and a torque shoulder-forming portion on the end of a pipe, and a box member having a tapered female thread, a metal seal-forming portion, and a torque shoulder forming-portion corresponding to these on the end of a pipe, a buttress thread having contact at the load flanks and the thread root surface and gaps at the thread crest surface and the stabbing flanks is mixed in a single joint with a rugged thread having contact at the load flanks and stabbing flanks and having gaps at the thread root surface and thread crest surface.

In order to manufacture a steel pipe for an air bag which can cope with increase in the pressure of gas blown into an air bag and decreases in the wall thickness of an accumulator, a steel having a composition, mass %, of:  if necessary at least one of Mo: at most 0.50%, Ni: at most 1.5%, Cu: at most 0.5%, V: at most 0.2%, Ti: at most 0.1%, Nb: at most 0.1%, and B: at most 0.005%, and also if necessary, at least one of Ca: at most 0.01%, Mg: at most 0.01%, and REM (rare earth elements): at most 0.01%, and a remainder of Fe and impurities is used to produce a steel pipe, and the pipe is then subjected to cold working to predetermined dimensions, then to heating to a temperature of at least the Actransformation temperature followed by quenching, and then to tempering at a temperature no higher than the Actransformation temperature.

High strength steel pipe for an air bag and a process for its manufacture

A male threaded joint tipped with a male lip having a male seating face and a male stop transverse surface proximate to the male seating face. A female threaded element includes for co-operation with the corresponding male threaded element, a female seating face and a female stop transverse surface provided on a female shoulder and proximate to the female seating face. The annular female shoulder zone is subjected to axial compression forces resulting from the pressure of the male and female stop surfaces and has an inner peripheral surface, the diameter of which is at least locally proximate to the female stop surface smaller than the diameter of the inner peripheral surface of the male lip. The ratio R of the two diameters is less than 1 but not less than 0.9.

Tubular threaded joint with reinforced stop

Threaded connection for oil country tubular goods and its method of manufacturing

A threaded connection for the oil country tubular goods, according to the invention, is provided with either an internal shoulder or an external shoulder or both, each comprising a seal portion and a torque shoulder, and characterized by satisfying the following conditions (1) and (2):

Threaded connection tubular goods

A threaded joint for an oil well pipe having (1) a tapered threaded having roughly the shape of a buttress thread, (2) a pin having a male thread and a box having a female thread, (3) a seal and a torque shoulder, characterized in that

Threaded joint for oil well pipes

A threaded joint for oil well pipes has excellent leak-tightness and a high disconnect torque and can withstand repeated make-ups. At the time of make-up, the load flanks (1) of the male and female threads contact each other, either the crest surfaces (3) or the root surfaces (4) are contacting and the other of the two pairs of surfaces has a gap, and a gap of at most 0.03 mm exists between the stab flanks (2) of the male and female threads.

Growing community of inventors

Izumiotsu, Japan

Miyuki Yamamoto