| 摘要 |
PURPOSE:To facilitate the production of a multipipe thermal sleeve and to reduce the man-hour for production, by interposing spacers between cylindrical members of the multipipe and subjecting the members to electron beam welding. CONSTITUTION:An annular spacer 19 is beforehand sandwiched between a cylindrical outside pipe 16 and the top end of a middle pipe 17 which are cylindrical members. The spacer is inserted up to the outside circumferential step part of a lock ring 20 formed at the top end of the pipe 18 and the entire circumference thereof is welded by electron beam welding 21 from the outside of the pipe 16 to join the pipe 17 and the pipe 16 to the ring 20. Spacers 22a, 22b, 23a, 23b- are interposed between the pipe 16 and the pipe 17 as well as between the pipe 17 and the pipe 18. The spacers 22a, 22b, 23a, 23b are then fixed by electron beam welding 24 to the pipe 18, pipe 17 or pipe 16 with which the spacers are respectively in contact. |
