Analysis of welding technique of butt welding flange

The welding method of the butt welding flange is: keep a certain distance between the nozzle of the welding torch and the groove of the pipe wall, grasp the welding torch with the thumb and index finger of your right hand, and swing the other 3 fingers against the pipe wall for support (or directly hang in the air for transportation). However, when the tube wall thickness is large, this method is not easy to form good protection and weld forming, and the tungsten electrode protrudes too long, which is easy to cause tungsten clamping defects. Swing welding method should be used.

　　The advantages of butt welding flange swing welding method are:

　　1) Since the nozzle of the welding torch is directly pressed in the groove and swings, the distance between the nozzle and the liquid molten pool is relatively close, so that the shielding gas can fully protect the molten pool;

　　2) The swing path of the swing welding method is formed according to the assembly gap and the groove shape. During the welding process, it can be heated evenly, so that a neat shape, uniform structure, and high-quality weld can be obtained.

  requires attention:

1) Butt welding flange welding current is slightly larger than traditional welding methods;

　　2) The elongation of the tungsten pole is determined according to the wall thickness of the tube, usually 4-5mm;

　　3) The flow of argon gas is slightly larger than traditional welding methods, about 8-10L/min;

　　4) The swing amplitude is 2mm from the blunt edge of the groove on both sides of the fusion;

　　5) The left and right hands cooperate flexibly, swing evenly, and wire evenly.

　　 Butt-welded flange swing technique welding technology can be used for thick-walled pipe welding, and can also be used for single-sided welding, double-sided forming, fillet welding, etc. It has been widely used in the welding of various pipelines and many important structures in oilfields. Its welding quality has been fully affirmed by the industry and has great application value.