Equipment and process for applying an external structural weld to piping and similarly shaped pressure boundary components

Abstract

An apparatus and/or process for applying a weld overlay to a nozzle or piping spool of complex configuration is disclosed. In an exemplary embodiment, the welding apparatus comprises a mounting assembly having a plurality of magnetic foot pads, a tension support rod attached at one end to one of the magnetic foot pads, an upper attachment pad at the opposite end of the rod, and a bottom attachment pad attached to at least one other magnetic foot pad; a travel guide, the travel guide attached to the upper attachment pad at one end and the bottom attachment pad at the other end; and a head assembly attached to the travel guide, the head assembly having: i) a track ring assembly having an inner ring and an outer ring, ii) at least two opposed weld heads attached to the inner track ring, iii) at least one movable wire feed drive mechanism on the track ring, and iv) a drive mechanism located on the outer ring of the track ring, the drive mechanism adapted to permit rotation of the inner ring and the weld heads around the component to be welded.

1 . A weld head assembly for a welding apparatus comprising:
 a track ring assembly for alignment around a centerline axis of a component to be welded, the track ring assembly having an inner ring and an outer ring;   a drive mechanism located on the outer ring of the track ring assembly, the drive mechanism adapted to permit rotation of the inner ring;   a first weld head and a second weld head, wherein the first weld head and the second weld head are attached on the inner track ring; and   a single command module for controlling the first weld head and the second weld head.   
     
     
         2 . The weld head assembly of  claim 1  further comprising a camera attached to each weld head for monitoring weld bead placement. 
     
     
         3 . The weld head assembly of  claim 1  wherein the drive mechanism includes a chain fixed to the inner ring to permit rotation of the inner ring. 
     
     
         4 . The weld head assembly of  claim 1  wherein the first weld head and the second weld head are attached opposite each other on the inner track ring for coordinated movement with the inner ring. 
     
     
         5 . The weld head assembly of  claim 1  wherein a single power supply for powering the first weld head and the second weld head. 
     
     
         6 . The weld head assembly of  claim 1  wherein the command module adjusts the first weld head and the second weld head to follow contours and transitions of the component. 
     
     
         7 . A welding apparatus comprising:
 a mounting assembly for attaching a welding apparatus to a structure, the mounting assembly having:   a first foot pad and a second foot pad,   a tension support rod pivotally attached at one end of the first foot pad,   an upper attachment pad pivotally attached at an opposite end of the tension support rod, and   a bottom attachment pad pivotally attached to the second foot pad;   a travel guide, the travel guide attached to the upper attachment pad at one end and the bottom attachment pad at the other end for selectively adjusting a position of the travel guide relative to the structure;   a head assembly attached to the travel guide, the head assembly including:   an inner ring and an outer ring;   a first weld head oriented opposite a second weld head, wherein the first weld head and the second weld head are attached to the inner ring;   a drive mechanism located on the outer ring, wherein the drive mechanism permits rotation of the inner ring; and   a single command module for controlling the first weld head and the second weld head.   
     
     
         8 . The welding apparatus of  claim 7  wherein there is a third foot pad and wherein the mounting assembly is attached to a structure other than the ground. 
     
     
         9 . The welding apparatus of  claim 7  wherein the first foot pad and the second foot pad are magnetic for attaching the welding apparatus to a metallic structure. 
     
     
         10 . The welding apparatus of  claim 7  further comprising a camera attached to each weld head for monitoring weld bead placement. 
     
     
         11 . The welding apparatus of  claim 7  wherein the drive mechanism includes a chain fixed to the inner ring to permit rotation of the inner ring. 
     
     
         12 . The welding apparatus of  claim 7  further comprising at least one wire feed drive mechanism movable on the inner ring. 
     
     
         13 . The welding apparatus of  claim 7  wherein the head assembly is attached to the travel guide by a mounting bracket. 
     
     
         14 . The welding apparatus of  claim 7  wherein the drive mechanism includes a chain fixed to the inner ring to permit rotation of the inner ring and the first weld head and the second weld head. 
     
     
         15 . The welding apparatus of  claim 7  wherein the command module adjusts the first weld head and the second weld head to follow contours and transitions of the component. 
     
     
         16 . The welding apparatus of  claim 7  wherein a single power supply for powering the first weld head and the second weld head. 
     
     
         17 . A welding process comprising:
 aligning a head assembly around an axis of a component to be welded, the head assembly having an inner ring and an outer ring, the inner ring including at least a first weld torch opposite a second weld torch;   initiating the first weld torch at an initial point for application of a first weld bead;   rotating the inner track ring to apply the first weld bead by the first weld torch on a side of the component;   terminating the first weld torch; and   initiating the second weld torch at the initial point; and   rotating the inner track ring in the reverse direction to apply a second weld bead by the second weld torch on an opposite side of the component, wherein a single command module controls the first weld torch and the second weld torch.   
     
     
         18 . The process of  claim 17  wherein a camera is attached to each weld head for monitoring weld bead placement. 
     
     
         19 . The process of  claim 17  wherein the first weld torch and the second weld torch are attached opposite each other on the inner track ring for coordinated movement with the inner ring. 
     
     
         20 . The process of  claim 17  wherein a single power supply powers the first weld and the second weld.