Invention Grant
- Patent Title: Threaded joint for steel pipes
- Patent Title (中): 钢管螺纹接头
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Application No.: US10765837Application Date: 2004-01-29
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Publication No.: US07360798B2Publication Date: 2008-04-22
- Inventor: Keishi Matsumoto , Kunio Goto , Toshiro Anraku , Shigeo Nagasaku , Hideo Yamamoto
- Applicant: Keishi Matsumoto , Kunio Goto , Toshiro Anraku , Shigeo Nagasaku , Hideo Yamamoto
- Applicant Address: JP Osaka FR Aulnoye-Aymeries
- Assignee: Sumitomo Metal Industries, Ltd.,Vallourec Mannesmann Oil & Gas France
- Current Assignee: Sumitomo Metal Industries, Ltd.,Vallourec Mannesmann Oil & Gas France
- Current Assignee Address: JP Osaka FR Aulnoye-Aymeries
- Agency: Clark & Brody
- Priority: JP2002-159563 20020531
- Main IPC: F16L15/00
- IPC: F16L15/00 ; C10M159/06

Abstract:
A threaded joint for steel pipes comprising a pin 1 and a box 2 each having a contact surface comprising a threaded portion 3 or 4 and an unthreaded metal contact portion 8 is provided with improved anti-galling propertied by forming a lubricating coating on the contact surface of at least one of the pin and the box, the lubricating coating exhibiting a self-repairing function by liquid lubrication and having a decreased greasiness. The lubricating coating is (1) a coating which comprises a lower lubricant layer which is in liquid form in the temperature range of above 0° C. and below 40° C. and an upper lubricant layer which is in solid form at 40° C., or (2) a coating which is semi-solid or solid at 40° C. and is formed of a mixture comprising a lubricating oil which is in liquid form in the temperature range of above 0° C. and below 40° C. and a wax which is in solid form at 40° C., the mixture preferably having been heated so as to liquefy the wax and dissolve in each other the wax and lubricant oil.
Public/Granted literature
- US20040239105A1 Threaded joint for steel pipes Public/Granted day:2004-12-02
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