Large electron beam butt welding plant for pipes - esp. for laying underground or undersea pipelines carrying petroleum or gas

摘要

The machine includes a rigid platform carrying a vertical drum rotated in steps of 120 degrees. At the top and bottom ends of the drum are two sets of three clamps. The clamps in each set are spaced at 120 degrees intervals, and carry a pipe from a loading and centering station to an intermediate station where the butt ends are machined prior to welding. The pipe is next moved by the drum to a welding station in which a vacuum chamber can be moved along the axis of the pipe, and contains a circular guide rail along which an electron gun can be driven in a circle round the pipe to make a butt weld. The centering station pref. has upper and lower centering pegs so each pipe can be exactly aligned before being clamped on the drum. System achieves accurate alignment of all the pipes being butt welded and then laid.