Bolted flange joints with full face gaskets: An analytical approach based on flexibility

The low leakage performance of flanges with full face gaskets is attributed to the reliability of the design method used in Appendix 2 and Appendix Y of the ASME code in assessing accurately the bolt and gasket load changes. The prediction of tightness of these bolted joints relies very much on the level of precision of the gasket contact stress during operation. The evaluation of this stress requires a flexibility analysis of the joint including the flange the gasket and bolt and the interaction between them. This paper analyses the distribution of gasket stress and the load change in bolted joints with full face gaskets. lt proposes a simple analytical approach capable of predicting flange rotation and bolt load change during operation. The method is based on the gasket-bolt-flange elastic interaction, including flange rotational flexibility. The proposed model is supported by comparison with numerical FEA of different size flanges.