Root Welding: shimless tube turn welding. In order to make the root easy to penetrate, the range of the strip should be selected in the vertical welding position. The method of operation can be straight or slightly wobbly crescent. If the gap between the butt joints is large, the arc extinguishing method can be used for welding. For thick-walled pipes, sometimes turning is laborious. At the same time, in order to prevent cracks at the root of the joint due to vibration during rotation, and to facilitate the operation, the pipe should be placed on a flat turntable before butt joint. When soldering, preferably before turning once. At the same time, the weld must have sufficient strength, and the distance between the two fulcrums close to the joint should not exceed 1.5-2 times the pipe diameter.
