METHODS AND APPARATUS FOR APPLYING METALLIC CLADDING TO INTERIOR SURFACES OF PIPE ELBOWS

摘要

An apparatus for applying a helical cladding bead to the interior surface of a pipe elbow has a rotor mounted to an elbow carriage so as to be rotatable about a primary axis. The elbow carriage is longitudinally movable parallel to the rotor's rotational axis. A radially-movable elbow collar is mounted to the rotor, and has means for mounting a first end of a pipe elbow. The second end of the elbow passes through a stationary frame with centering means for keeping the elbow's curved centerline tangential to the primary axis. A weld arm, extending from a weld arm carriage into the second end of the elbow, is sinuously configured so that it will not interfere with the elbow. The weld arm is rotatable about the primary axis in coordination with the rotor. A weld head is mounted at the extending end of the weld arm so as to remain spatially fixed regardless of rotation of the weld arm. An integrated drive mechanism rotates the rotor, moves the elbow carriage longitudinally, moves the elbow cradle radially, and rotates the weld arm in synchronization with the rotor, all in a coordinated fashion such that the elbow's center of rotation orbits around the primary axis in a plane perpendicular thereto. The elbow moves through the stationary frame at an average rate equal to one weld bead width per rotation, thus resulting in the deposition of a continuous helical weld bead cladding the interior surfaces of the elbow.