Title:
STEEL PIPE THREADED COUPLING
Document Type and Number:
WIPO Patent Application WO/2021/044862
Kind Code:
A1
Abstract:
The present invention provides a threaded coupling, for a steel pipe having a large diameter size, which can provide high torque-resistance performance and high sealing performance, and which has shear-resistance performance corresponding to the size of the steel pipe to be linked. A steel pipe threaded coupling 1 has: a tubular pin 10 provided to a tip section of a steel pipe 2 having a large diameter size; and a tubular box 20 into which the pin 10 is screwed and which is fastened to the pin 10. The pin 10 has male threads 11 comprising tapered threads. The box 20 has female threads 21 comprising tapered threads. The male threads 11 and the female threads 21 are wedge-shaped threads in which the thread ridge span gradually narrows, the cross-sectional shape of the thread ridges being dove-tailed. The male threads 11 are designed to satisfy the following formula so that the thread ridge span at a thread terminus end on the tip side is of a size matching the size of a pipe body of the steel pipe 2. 0.4≤{(DＷ+2TH)2-DW
2}×Wmin/(OD2-ID2)≤0.6
Inventors:
OKU YOUSUKE (JP)
DOUCHI SADAO (JP)
DOUCHI SADAO (JP)
Application Number:
PCT/JP2020/031462
Publication Date:
March 11, 2021
Filing Date:
August 20, 2020
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
VALLOUREC OIL & GAS FRANCE (FR)
VALLOUREC OIL & GAS FRANCE (FR)
International Classes:
F16L15/06; E21B17/042
Domestic Patent References:
| WO2019076622A1 | 2019-04-25 | |||
| WO2017213048A1 | 2017-12-14 | |||
| WO2018052140A1 | 2018-03-22 | |||
| WO2015194193A1 | 2015-12-23 |
Foreign References:
| JP2012512347A | 2012-05-31 | |||
| US4822081A | 1989-04-18 | |||
| CN205558826U | 2016-09-07 | |||
| JP2016130668A | 2016-07-21 |
Other References:
See also references of EP 4027044A4
Attorney, Agent or Firm:
UEBA, Hidetoshi et al. (JP)
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