The Establishment Of Sealed System Leak Rate Model And Failure Analysis Based On Bolted Flange

The bolted flange gasket is widely used in pipe connection of Petrochemical, Pressure vessel and piping, Aerospace. This paper is mainly focus on the establishment of sealed system leak rate model and failure analysis based on bolted flange gasket.Firstly, the current situation of bolted flange gasket sealing system was introduced, the detriment of security, economic and environment which lead by leak was analysis, and it’s urgent to avoid the failure of sealed system and guarantee stop leaking.Secondly, according to the experiment from gasket pressure stress, medium pressure, medium viscosity, temperature, the factors which influence the leakage were analysis. In addition, the creep behavior and compression-resilience were researched as well. The result of experiment indicated that gasket pressure stress have the exponential function relationship with leak rate. The width of gasket has inverse to leak rate, and the difference of squares of medium pressure have a linear relationship with leak rate. And medium viscosity leakage has an inverse relationship with leak rate.Once again, the failure of gasket seal was studied. The sealing performance levels were divided from the close degree. Then through the reaction theory, the causes of failure were analyzed from the perspective of energy.Finally, NPS4Class150was selected as flange to establish the three-dimensional finite element model of flange gasket, then the results showed that contain different bolt preload, same medium pressure and the cloud of stress. Result indicates that the distribution trend of bolt preload is roughly the same, the stress will be raised no matter the bolt preload or medium pressure is enhanced.