THE SEALING BEHAVIOR OF LARGE DIAMETER FLANGED CONNECTIONS AND A METHOD TO DETERMINE BOLT LOADS TO SATISFY TIGHTNESS CRITERIA

摘要

With the recent increase of a safety and environmental concern, the tightness of gasketed flanged connections becomes an important issue. However, the estimation of bolt loads to satisfy the tightness of gasketed flanged connections has not yet been fully established, especially in the case of large diameter flanges. In this paper, the sealing behavior of a large diameter gasketed flanged connection, in which 16 inch blind flanges were used, was examined experimentally. The variations of bolt loads were also measured when the flanged connection was subjected to an internal pressure. In the experiments, two kinds of sheet gaskets were used. It was shown that the bolt loads of large diameter flanges were reduced significantly and a gross leak occurred due to a large thrust force caused by an internal pressure and that the gasket characteristics affect the sealing behavior significantly. The test results were compared with those of small diameter gasketed flanged connection to highlight the difference of the sealing performance.