FEM Stress Analysis and Sealing Performance in Bolted Flange Connections With Cover of Pressure Vessel Subjected to Internal Pressure Available to Purchase

The stresses of a bolted flange connection with a cover of pressure vessel (CPV) in which a spiral wound gasket is inserted, under internal pressure are analyzed taking account a hysteresis of the gasket using the finite element method (FEM). The leakage tests were also conducted for an actual bolted flange connection with a CPV and a spiral wound gasket. Using the calculated contact gasket stress distribution of the bolted flange connection with the CPV under internal pressure and the tightness parameter, the values of the new gasket constants were obtained by taking into account the changes in the contact gasket stress. A difference in the new gasket constants between the estimated values obtained from the actual bolted flange connection with the CPV and the values obtained by the PVRC procedure was small. In addition, a method to determine the bolt preload for a given tightness parameter was demonstrated. The obtained results of the bolt preload for the bolted flange connection with the CPV were in a fairly good agreement with those obtained by the PVRC procedure under a lower pressure application. However, a difference in the bolt preload was about 7% when the internal pressure was increased.