A New Approach to Model Bolted Flange Joints With Full Face Gaskets

The poor leakage performance of flanges with full face gaskets is attributed to the low reliability of the existing design methods, and in particular, their lack of assessing accurately the bolt and gasket load changes. The prediction of tightness of bolted joints relies very much on the level of precision of the gasket contact stress during operation. The accurate evaluation of this stress requires a flexibility analysis of the joint that includes the flange, gasket, and bolts, and the interaction between them. This paper analyzes the distribution of gasket stress and the load change in bolted joints with full face gaskets. It 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 finite element analysis of different size flanges.