The Performance Of Flange Joint With Double Wedge Angle Ring Gasket Under Bending Moment And Temperature

Bolted flange connection,as the most common disassembly connection used in modern process industry,such as in food,machinery,aerospace and other industries.Most of these industries are involved in high temperature and high pressure and are more seriously affected by external environment.Therefore,the sealing performance of bolt flange joints is higher,especially in recent years,with the increasing demand for the environment,the research on sealing performance of bolt flange joints is more focused.However,with the complexity of the bolt flange connection system,the large number of use in practical application and the connection structure often work in the complex and changeable load conditions which make it a relatively weak link in the pressure vessel and pipe connection,so the problem of the failure of the bolt flange connection structure under the effect of high temperature and external load has needs to be solved urgently.In this paper,the ABAQUS was utilized to calculate the rigidity,strength and sealing performance of double wedge angle ring gasket joint.Its size is three inches and works in 5MPa under the bending moment and high temperature.The results were shown that:(1)ABAQUS is used to analyze the strength and sealing performance of the double wedge ring gasket flange joint under precondition and operation conditions.The analysis results show that,under the effect of bolt pretightening force,internal pressure and end load,the components of the double wedge angle ring flange joint meet the requirements of strength and stiffness and the minimum contact stress of the gasket meets the requirements for sealing.(2)As the double wedge angle ring flange joint works in the high temperature environment,in order to accurately analyze the leakage mechanism of the double wedge angle ring flange joint,on the basis of the conventional working condition analysis of the bolt flange joint,the thermal analysis under the high temperature environment is carried out.The sealing performance of bolted flanged joints under different temperatures is analyzed by sequential coupling method.The analysis shows that when the temperature reaches 972 K,the stress drop of the gasket is very obvious,and the flange connection structure will leak.(3)The stress of the double wedge angle ring flange joint under bending moment is evaluated.When the bending moment reaches 3000 N m,the primary stress corresponding to path 1-1 is greater than the allowable stress for a standard double-wedge ring flange.That is,the strength check cannot be performed,resulting in failure of the bolt flange joint seal.The whole analysis has important reference value for the application of double wedge angle in practice.