1 IntroductionAmong the various metal joining processes, orbital TIG welding has become a well-established method, although there is a notable lack of information on the various possibilities of this challenging still-in-progress technique of research. The aerospace industry, pharmaceutical industry, high-speed rail, nuclear industry, food industry, microelectronics industry, oil and gas industry rely on orbital welding. This report provides basic information about the orbital welding process and related equipment: technical approach, advantages, common and special applications, but also restrictions and limitations. Orbital welding uses the tungsten arc welding (GTAW) process as the source of the electric arc that melts the base material to form the weld. During GTAW, an electric arc is formed between the workpiece and a tungsten electrode. To strike the arc, a high voltage signal will ionize the shielding gas to generate a passage for the welding current. A capacitor discharges current into the arc to decrease the arc voltage to the point where the power can be regulated. Power supplies respond to demand and provide current to maintain the arc.2 What is orbital welding? Orbital welding is the first choice for joining pipes whenever high-quality results are required. The welding moves around the pipes to be joined, guided by a mechanical system. The name orbital comes from the circular movement of the welding tool around the workpiece. Generally, the orbital welding technique covers two main fields of application: a) Union of tube to tube/tube to tube b) Welding of tube to tube sheet 3 Welding procedure Using manual welding, it is very difficult to achieve the highest standards of quality and safety. This is mainly due to the ce...... middle of paper...... DefectsOrbital welding has defects that include misalignment, lack of penetration, a huge crack, and discoloration due to poor internal diameter purge. This welding would be considered unacceptable by any standard.8 DisadvantagesThe following are the disadvantages of the orbital welding process:• Increased cost of equipment• More problems with equipment• Additional training for welders• Additional maintenance and spares9 ConclusionAlong with current methods of using hot and cold wire TIG welding, there has also been constant progress in the development of other welds which allow for a whole range of new applications. Orbital welding can provide reproducible quality using wide-ranging techniques. This can be achieved to a high level even when using unusual materials, small pipe diameters, thick walls and even in a harsh working environment.10 References