摘要 |
Continuous coil tubing made from shorter lengths of flat metal strip which are spliced end-to-end and formed into tubular form and seam welded and thereafter introduced into a forging or hot reduction process. Finished coil tubing is withdrawn from the process at a different rate than flat metal strip is fed into the process. Welds made to the flat metal strip blend into and substantially disappear from the finished coil tubing.
|