Effect of thermal loading on sealing behavior of single and twin-gasketed flange joints

Gasketed flange joints are usually subjected to internal pressure at high temperature. The most important requirement of flange joint is to provide leak-free joint under operating condition. In the present study, temperature-dependent nonlinear gasket properties of spiral-wound gasket at elevated temperatures are obtained experimentally and included in the analysis. The relaxation of gasket contact stress in both single and twin-gasketed joints at elevated temperatures is compared. It is observed that the ability to withstand internal pressure decreases with increase in temperature in both single and twin-gasketed flange joints. But, the twin-gasketed flange joint is found to withstand higher internal pressure than single-gasketed joint at a given bolt preload and temperature. The influence of gasket seating surface rotation on the distribution of gasket radial contact stress at elevated temperature is studied. The effect of elevated temperature on flange stresses of twin-gasketed joint is also examined.