Sealing Performance of Bolted Flange Joints at High Temperature

High temperature and pressure have a remarkable effect on the sealing performance of bolted flange joint.The thermal and structural analysis of DN100 mm,PN40 MPa pipe flange were conducted using finite element method.The temperature distribution on flange,gasket and bolt was discussed.The stress changes at tightening,pressure and elevated temperature were analyzed.The results show that there is a gradient in temperature along the radial direction of flange,bolt and gasket.The gasket stress can be obviously reduced under pressure.After the temperature is raised,the gasket′s outboard stress decreases while the inboard stress increases.The bolt stress will increase under pressuring or temperature increasing.