2010 Volume 48 Issue 3 Pages 132-139
Non-asbestos gasket is recently widely used as a substitute of compressed asbestos sheet gasket. Even though the PTFE gasket has excellent seal performance, heat resistance, and chemical resistance, a large reduction of axial bolt force under high temperature condition is a serious problem for a bolted connection with PTFE gasket. There is no method of evaluating the long-term and high temperature characteristic of the gasket. What is a dominant factor for bolt force reduction in the connection is not clear because of complex high temperature performance of such soft gasket.
In this study, method of estimate sealing life of bolted connection with soft gasket, finite element simulations to investigate gasket contact stress reduction of bolted flange connection with soft gasket are performed under high temperature conditions, where temperature and time dependent gasket material properties, such as stress-strain relation, thermal expansion factor and creep performance, are measured and employed. And, sealing performance under high temperature conditions are testes.
As a result, method of estimate sealing life and examine maintenance of bolted connection with soft gasket is performed. The method give information of sealing life and method for extend life. Here, the gasket that can be applied is limited to the PTFE gasket.
