Safety Seal Performance Analysis Of Bolt Flange Joint

Bolt flange connection structure in the chemical industry,oil refining and other industries in the pressure vessel and pipeline design is widely used.The flange connection joints are generally used in a large number of cases,and the working conditions are very complex,and most of the device internal media is the flammable,explosive toxic liquid or gas.Once the joint sealing property problems appear,the internal media is likely to leak,Resulting in casualties,property damage and environmental pollution.Scholars at home and abroad have made extensive research on the design method and relevant norms and standards of flange connection.They have achieved very fruitful research results,but the research on gasket,the most important structure of the bolt flange connector,is relatively few.Fuzzy logic theory has made a lot of success in various applications since its introduction.The theory does not need accurate mathematical model and is suitable for dealing with nonlinear and dynamic changes.The nature of the gasket is complex and the relationship between the parameters affecting the leakage is non-linear.There is no better mathematical model to be calculated,and the fuzzy logic system can solve this problem.Therefore,it is necessary to study the gasket sealing performance of bolt flange joints based on fuzzy logic.Firstly,the sealing mechanism,the leakage form and the main factors influencing the leakage of the gasket in the bolt flange connection system are analyzed.The main measures to prevent the sealing of the gasket seal are as follows: selecting the appropriate gasket,controlling the flange deformation,selecting the appropriate Of the bolt preload.And the two most widely used methods are simply analyzed.Secondly,collects the EU and China flange connection design standards,norms,then analysis the background and content of the development of the standards.According to the link between the standards,establish the standard system structure diagram of gasket performance.And the differences between the EU and GB gasket series of standards are analyzed from three aspects: the gasket characteristics,gasket size,gasket quality.Then put forward a few suggestions on improving the domestic gasket standards from the perspective of China's national conditions.Then,the fuzzy logic theory foundation,system rules and so on are introduced briefly,which provides a new theoretical basis for the research of gasket selection andsealing performance.Based on the fuzzy logic theory,the fuzzy logic model of gasket sealing performance is established,and the suitable gasket parameters and fuzzy rules are determined.Finally,using Visual Basic 6.0 software,the software of gasket sealing performance evaluation system based on fuzzy logic is designed.And a flexible graphite spiral wound gasket is taken as an example to demonstrate the simulation.