Abstract: [Problem] To provide: a molten metal plating furnace that can increase plating quality and work efficiency; a system for producing and method for producing a metal plated product; and a metal plated steel tube obtained by means of the method for producing.

Abstract: A system and method for adjusting dipping time in a continuous steel pipe manufacturing line. The system manufactures a steel pipe of which inner and outer faces or any one face thereof is subjected to molten metal-plating from a steel sheet in a continuous manufacturing line, and includes an inner-face plating performing part for molten metal-plating by pouring molten metal to the upper side of the steel sheet corresponding to the inner face of the steel pipe, a steel pipe forming part that obtains a continuous steel pipe by continuously cold-forming the steel sheet subjected to the inner-face plating into a tubular shape and seam-welding a longitudinal end face joint portion of the steel sheet formed in the steel pipe, and an outer-face plating performing part for molten metal-plating by dipping the outer face of the steel pipe into the molten metal, in which a dipping length of the molten metal is adjusted in the inner-face plating performing part and/or the outer-face plating performing part.

Abstract: [Problems] To provide a process for producing a thermal sprayed, metal plated steel tube having a metal layer substantially uniform and favorable over the whole surface in a highly productive manner. [Means for solving] A process for producing a metal tube comprising continuously forming a metal plate composed of a first component into a tubular shape and continuously welding its butted ends to form the metal tube, wherein, after the continuous welding, a metal layer composed of a second component which is different from the first component is formed by thermal spraying directly over the surface of the metal tube, the metal layer having no discontinuities in the circumferential and lengthwise directions. Especially it is preferred that the process comprises a process step of making the thickness distribution of the metal layer more uniform after formation of the thermal sprayed metal layer over the external surface.

Abstract: To provide a process for producing a thermal sprayed, metal plated steel tube having a metal layer substantially uniform and favorable over the whole surface in a highly productive manner. [Means for solving] A process for producing a metal tube comprising continuously forming a metal plate composed of a first component into a tubular shape and continuously welding its butted ends to form the metal tube, wherein, after the continuous welding, a metal layer composed of a second component which is different from the first component is formed by thermal spraying directly over the surface of the metal tube, the metal layer having no discontinuities in the circumferential and lengthwise directions. Especially it is preferred that the process comprises a process step of making the thickness distribution of the metal layer more uniform after formation of the thermal sprayed metal layer over the external surface.

Abstract: Steel strip (1) is cleaned by shot blast machine (3) and its upper surface is coated with zinc in molten plating device (4). The strip is formed by roll forming machine (6) into a tube and the outer surface of the tube is coated by plating device (11).

Abstract: A connection structure and method comprising the steps of providing a cylindrical joint member for connecting a first pipe and a second pipe inserted into opposite ends of said cylindrical joint towards the center of said cylindrical joint member and holding said pipes in such a position that their ends are separated only by a narrow gap, and compressing both ends and the center of said cylindrical joint member to form airtight seals between said first and second pipes and the ends of said cylindrical joint member and also between the ends of said first and second pipes and the middle part of said cylindrical joint member.

Abstract: A joint is formed at adjacent ends of tubes (5, 7) by inserting the ends of the tubes into opposite ends of sleeve (1) until the tube ends engage centrally positioned inwardly extending protrusion (3). The sleeve (1) is crimped inwardly into frictional engagement with the tubes (5, 7), only at the middle portion and at the end portions of the sleeve to partially deform the sleeve and the tubes at the adjacent ends of the tubes and at positions of the tubes displaced from the tube ends.