Development of Fully Automatic Both-Side Welding (GMAW) for Pipeline

Development of a fully automatic both-side welding method for pipeline construction was achieved in terms of combining an internal clamp and welding device with a two external head welding device. A double-V butt joint of 40 degree geometry was applied with simultaneous three head operation (one internal and two external heads), reducing the deposited area to a half and increasing the welding rate by about five times in comparison with the former 60 degree joint geometry and an external single head GMA penetration welding method. The new process also provides the method of inprocess on-line tracking of the weld line as the welding proceeds, because the optical sensor is capable of detecting the variation in. parameters such as joint and deposit geometries. In addition, as the welding conditions can be properly controlled under a real time, it was achieved to stabilize the weld quality and save labor.