What type of welding is commonly used for joining pipes?

The correct answer highlights that pipe welding commonly uses SMAW (Shielded Metal Arc Welding) or GTAW (Gas Tungsten Arc Welding) techniques. These methods are favored in pipe welding due to their versatility and effectiveness in creating strong, reliable joints.

SMAW is widely used for its adaptability to various positions, making it suitable for fieldwork where pipes might need to be welded in less-than-ideal conditions. It is also capable of welding a variety of materials, including carbon steel, which is commonly used in piping systems.

GTAW, on the other hand, is preferred for applications requiring high-quality welds with minimal contamination. This technique is especially useful in industries like oil and gas or chemical processing, where the integrity of the weld joint is crucial due to the high-pressure environments often encountered.

The other options do not accurately reflect the practices in pipe welding. While MIG welding can be used in some instances, it is not the primary method for pipe welding. The statement regarding stick welding being inappropriate is misleading, as SMAW is indeed a fundamental technique in this field. Asserting that pipe welding requires no specific technique neglects to acknowledge the importance of selecting the appropriate welding method based on the materials and conditions involved.