FEM Stress Analysis and the Evaluation of Sealing Performance of the Box-Shaped Flange Connections with Gaskets Subjected to Internal Pressure (In the Case Where the Wavy Oil-Pan Shaped Flange Connection is Used)

Abstract

The contact gasket stress distribution in a wavy oil-pan shaped flange connection under the internal pressure was examined using finite element method (FEM) for estimating a location where a principal leakage occurred and for calculating the amount of leakage. Leakage tests were also conducted to validate the estimated results using an actual connection under the internal pressure. The effects of flange shape on the contact gasket stress distributions were examined. The sealing performance for the difference types of inner fluid (gas/liquid) was evaluated from the contact gasket stress distributions. It was seen that the estimated amount of leakage was in a fairly good agreement with the measured results. The difference of the contact gasket stress distribution and the sealing performance were shown between the box-shaped flange and the wavy oil-pan shaped flange connections. In addition, a method how to determine the bolt preload taking into account the allowable amount of the leakage was demonstrated. Furthermore, discussion was made on the effect of the bolt pitch on the sealing performance.