PLASMA ARC WELDING ROBOT FOR TGZ-LNG MEMBRANE SHEETS

A portable welding robot has been developed which utilizes the plasma arc welding process with pulse arc, for TGZ-LNG tank corrugated membrane sheets. The robot is very compact, durable, easy to operate and readily adaptable to high-volume welding tasks for the corrugated membrane sheets. The robot offers excellent productivity improvement due to the characteristics of plasma arc, and high-speed welding is approximately 2.5 times faster than existing automatic welding machines. Since a reliable precise seam tracking system using a laser sensor has been equipped to the robot, fully automatic welding in all round welding postures can be efficiently achieved for the lap joints of corrugated membrane sheets. The robot was successfully applied to the fabrication of a mock-up model tank, and the reliability of weld-quality was also verified.