Stress Characteristics of Large Diameter Pipe Flange Connection With Non-Asbestos Gasket Under Elevated Temperature

Since the flange rotation caused by internal pressure affects the sealing performance of pipe flange connections more by increasing the pipe nominal diameter, it is important to evaluate the sealing performance of larger nominal diameter pipe flange connection. However, most experiments were conducted with small-scale model due to the difficulty of large-scale experiment and numerical analyses containing uncertainties because of the lack of material models of gaskets. In addition, a sealing performance evaluation at high temperature is more difficult due to the thermal effect though the thermal condition is not avoidable in practical use. In this study, the 20” diameter pipe flange connection was used as a large nominal diameter pipe flange connection to analyze the stresses in the connection. In the FE analysis, the experimentally obtained material properties were used and the effect of diameter on the sealing performance was evaluated. The analysis revealed the thermal effect and the effect of flange rotation on the sealing performance. Moreover, the effect of material properties on the contact stress and hub stress of the pipe flange connections was evaluated. The experimentally obtained result was discussed with the FE result in this study.