Title:
STEEL PIPE SCREW JOINT
Document Type and Number:
WIPO Patent Application WO/2017/213048
Kind Code:
A1
Abstract:
Provided is a steel pipe screw joint that is capable of improving sealing performance against inner pressure without reducing sealing performance against outer pressure. A steel pipe thread joint (1) is provided with a pin (10) and a box (20). The pin (10) has: a pin lip (11) that includes a pin inner seal surface (11a) and a nose (11b); and a male thread (13). The male thread (13) and a female thread (23) of the box (20) are formed as a tapered screw having a dovetail shape. In a fastened state, the inserted flank surface of the male thread (13) and the inserted flank surface of the female thread (23) face each other with a gap therebetween. A distance D between the male thread (13) and the pin inner seal surface (11a) is 1.5 times or more than the thread pitch of the male thread (13). The length L of the nose (11b) is larger than the thread pitch of the male thread (13). The difference between the distance D and the length L is equal to or less than the thread pitch of the male thread (13).
Inventors:
SUGINO MASAAKI (JP)
DOUCHI SADAO (JP)
YAMAMOTO YASUHIRO (JP)
DOUCHI SADAO (JP)
YAMAMOTO YASUHIRO (JP)
Application Number:
PCT/JP2017/020651
Publication Date:
December 14, 2017
Filing Date:
June 02, 2017
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP (JP)
VALLOUREC OIL & GAS FRANCE (FR)
VALLOUREC OIL & GAS FRANCE (FR)
International Classes:
F16L15/04
Domestic Patent References:
| WO2016056222A1 | 2016-04-14 | |||
| WO2015033997A1 | 2015-03-12 | |||
| WO2015194193A1 | 2015-12-23 |
Foreign References:
| US4795200A | 1989-01-03 | |||
| JP2001056075A | 2001-02-27 | |||
| JP2010520981A | 2010-06-17 | |||
| EP1302623A1 | 2003-04-16 |
Other References:
See also references of EP 3470720A4
Attorney, Agent or Firm:
UEBA, Hidetoshi (JP)
Download PDF: