Study on developing pipework repairing system using laser beam and remote evaluation method of the repairing quality

Furusawa, Akinori   

In this work, it is reported that pipe work repairing system and evaluation method of the repairing quality. The repairing system, which is composed of the insertion laser-torch, rotating mechanism, hybrid optical fiber and CW laser source, enable us to repair and reprocess inner surface of the pipework. Operators are able to manipulate the system while monitoring the laser irradiation point through the hybrid optical fiber. On the other hand, the repairing quality is confirmed by visual images, it is natural of developing remote evaluation method for the repairing quality to enhance the value of the repairing system. One of the most promising techniques for remote repairing quality evaluation is ultrasonic guided wave. In this work, we focus on the evaluating butt-welding quality with guided wave, investigating its applicability experimentally. Guided wave is generated and measured on butt-welded pipes that are butt-welded in different conditions. Through the experiments and investigation of the wave profiles, it is found that welding condition effects on the strength of the guided wave detecting signal, revealing its applicability and obtaining some knowledge to establish remote repairing quality evaluation method.