Title:
THREADED JOINT FOR STEEL PIPE
Document Type and Number:
WIPO Patent Application WO/2021/261063
Kind Code:
A1
Abstract:
According to the present invention, the shear resistance of a first thread ridge 111 at the tip of a male thread 11 is improved by setting the curvature radius r1 of a load-surface bottom portion of the first thread ridge 111 so as to be, when Th represents a thread ridge height, not less than Th × 0.14, more preferably, not less than Th × 0.16. Further, the high torque resistance is maintained by: increasing the number of thread ridges and increasing a contact area of the load surface by setting a thread pitch to be small; increasing the contact area of the load surface by setting only the curvature radius of the load-surface bottom portion of the first thread ridge at the tip of the male thread to be large, but setting the curvature radius of other portions to be small; and the like.
Inventors:
WADA AKIRA (JP)
OKU YOUSUKE (JP)
ANDO YOSHINORI (JP)
OKU YOUSUKE (JP)
ANDO YOSHINORI (JP)
Application Number:
PCT/JP2021/015974
Publication Date:
December 30, 2021
Filing Date:
April 20, 2021
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
VALLOUREC OIL & GAS FRANCE (FR)
VALLOUREC OIL & GAS FRANCE (FR)
International Classes:
F16L15/04; F16L15/06
Domestic Patent References:
| WO2020075366A1 | 2020-04-16 | |||
| WO2020039750A1 | 2020-02-27 | |||
| WO2018135267A1 | 2018-07-26 | |||
| WO2017213048A1 | 2017-12-14 |
Foreign References:
| JPH0415385A | 1992-01-20 | |||
| JP2015505944A | 2015-02-26 | |||
| JP2015501906A | 2015-01-19 | |||
| US20190195030A1 | 2019-06-27 | |||
| JP2012526931A | 2012-11-01 | |||
| JP2016533462A | 2016-10-27 | |||
| JP2007504420A | 2007-03-01 |
Other References:
See also references of EP 4174354A4
Attorney, Agent or Firm:
UEBA, Hidetoshi et al. (JP)
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