Invention Grant
- Patent Title: Threaded connection for steel pipe
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Application No.: US16627850Application Date: 2018-10-02
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Publication No.: US11313181B2Publication Date: 2022-04-26
- Inventor: Masaaki Sugino , Yousuke Oku , Keita Inose
- Applicant: Nippon Steel Corporation , Vallourec Oil and Gas France
- Applicant Address: JP Tokyo; FR Aulnoye-Aymeries
- Assignee: Nippon Steel Corporation,Vallourec Oil and Gas France
- Current Assignee: Nippon Steel Corporation,Vallourec Oil and Gas France
- Current Assignee Address: JP Tokyo; FR Aulnoye-Aymeries
- Agency: Banner & Witcoff, Ltd.
- Priority: JPJP2017-206157 20171025
- International Application: PCT/JP2018/036859 WO 20181002
- International Announcement: WO2019/082612 WO 20190502
- Main IPC: E21B17/042
- IPC: E21B17/042 ; F16L15/04

Abstract:
A threaded connection for steel pipe is provided that improves its internal-pressure sealability while maintaining the high external-pressure sealability of a threaded connection having a nose used in a steel pipe with large diameter and large wall thickness. In a threaded connection for connecting steel pipe bodies each having an outer diameter equal to or larger than 7 inches and a wall thickness equal to or larger than 0.7 inches, Expression (1) in the description is satisfied and tB/tL>1.4, where δ [mm] is the clearance between the outer surface of the pin and the inner surface of the box upon make-up as measured at the borderline between the pin taper surface and the pin round surface, D [inch] is the outer diameter of the steel pipe body, t [inch] is the wall thickness of the steel pipe body, L [mm] is the distance between a pivot point, which is a position, in the region of contact between the pin sealing surface and the box sealing surface, which is closest to the tip of the pin, and the tip of the pin upon make-up as measured along the pipe-axis direction, tL [mm] is the wall thickness of the pin as measured at the pivot point, and tB [mm] is the wall thickness of the box as measured at the pivot point.
Public/Granted literature
- US20200248509A1 Threaded Connection for Steel Pipe Public/Granted day:2020-08-06
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