Guidelines For Pipe Welding
The symbols shown below are used throughout this manual to call attention to and identify possible hazards. When you see the symbol, watch out, and follow the related instructions to avoid the hazard. The safety information given below is only a summary of the more complete safety information found in the Safety Standards listed in Section 1-5. Read and follow all Safety Standards. Only qualified persons should install, operate, maintain, and repair this equipment. A qualified person is defined as one who, by possession of a recognized degree, certificate, or professional standing, or who by extensive knowledge, training and experience, has successfully demonstrated ability to solve or resolve problems relating to the subject matter, the work, or the project and has received safety training to recognize and avoid the hazards involved. During operation, keep everybody, especially children, away.
Begin welding in the 12 o'clock position. As with the 1G position, start the arc in the center of a tack weld using a 5- to 10-degree drag angle and a 3/8- to 5/8-in. stick-out. At the start of the weld, keep the arc in the center of the puddle, but move the electrode back and forth across the gap using a half moon motion (with the face of the moon pointing down). At about the 1 o'clock position, gravity starts to push the puddle down the joint. Once gravity takes over, stop weaving and concentrate on directing the electrode into the center of the weld puddle. At about the 5-o’clock position, us a slight side-to-side motion until reaching 6-o’clock, ending the bead on the feathered tack weld. The side-to-side motion flattens the weld bead and minimizes grinding. If the weld does not end on a tack weld (e.g., the operator breaks the arc for whatever reason), this may lead to a pin-hole at the end of the weld. Grind out the end of the weld before resuming. After completing the root pass, also grind out starts, stops and high points before making the first fill pass (remember that the root pass with the modified process can eliminate the hot pass).
