Abstract
Recently, in the power plant piping, the wall-thinning problem by high temperature water and a two-phase flow (high temperature water and steam) attracts attention. Since the wall-thinning mechanism was not clarified, it is the purpose which understanding the mechanism of wall-thinning in plant, installed the piping corrosion test facility in which a long-term continuous test is possible, and started the wall-thinning examination of carbon steel piping. In addition, the ultrasonic sensor for high temperature, which can be measured in the state of the high temperature, was installed, and monitored wall thickness change during an examination period. For about two months, as a result of performing monitoring, the measured piping thickness was falling uniformly and checked that this monitoring system had caught the tendency of wall thinning. The difference of a monitoring result and the thickness measurement result after an examination was small. It identified that this monitoring system could accuracy monitoring also in high temperature.
