Uphill Welding with Pipes in an Angular (6G) Position
The procedures shown in Fig. 10-3 are used when the pipes to be welded are at an angle, or approximately in the 6G position. In this case the joint is a butt joint. The bead is started by overhead welding at the lowest part of the pipe. As the bead progresses around the pipe, the welding procedure changes slightly. The welder must pay careful attention to the electrode angle, which is 10 to 15 degrees, and to the side angle, which is 15 degrees, as shown in Fig. 10-3B. By pointing the electrode toward the upper edge of the joint, the arc force assists in preventing the puddle from drooping downward. Also, by pausing when the arc is against this edge, sufficient metal is deposited to assure good fusion and to prevent undercutting.
Fig. 10-3. Weave patterns used for uphill welding of pipe joints in angular (6G)
Starting at the 6 o’clock position, the bead is welded by using a slanted “loop” weave, as shown inside the circle in Fig. 10-3A. This
weave allows the puddle to cool slightly, thereby preventing the molten metal from dripping. A pause is made against the upper edge.
Along the side of the joint, the weld will assume the characteristic of an uphill vertical weld, As shown in Fig. 10-3A, a slightly modified slant weave should be used here, while pausing at both edges of the joint.
When the tendency of the metal to sag diminishes near the top of the joint, the welder should revert back to the slanted ‘loop” weave, pausing only at the upper edge. Both sides of the pipe are welded in this manner.
If the wall thickness of the pipe exceeds 3/8 inch, a weave should not be used. In this case, the joint should be filled by welding a series of stringer beads, made by moving the electrode upward, at a slow, steady pace without extensive weaving, as in Fig. 10-4.