Abstract
The purpose of the present study is to clarify the mechanism that the internal pressure of the flare fitting joint increases by freezing of the dew condensation water. The experimental apparatus to be able to measure supercooling phenomenon in the model joint was built, and the experiments that cooled the model joint was carried out by changing the volume of water inside the joints. It was clarified that the expansion pressure was generated depending on the transition of supercooled water freezing, even if the inside of model joint was not filled with water.
