In-service Pressure Vessel Strength Assessment And Defect Treatment Based On Finite Element Method

Safety analysis and risk assessment of the operating conditions of pressure vessels is a very important topic in the risk assessment of equipment within the chemical industry today.Abnormal wall thickness measurements and cracks found in the main pressurised components are two of the most common problems that occur in the periodic inspection of pressure vessels.Pressure vessels due to various processing thinning,abrasion or corrosion and other reasons appear insufficient wall thickness,shell,pipe joints or welding seams and other parts,may be in the manufacturing,installation,use process to form some cracks,pits and other defects of different geometric shapes,which can often become an important cause of future equipment failure.Therefore,the strength assessment of in-service pressure vessels and the calculation and analysis of the defects they contain are an important part of the management and safety evaluation of the use of pressure-bearing equipment.In this study,the current technical specifications for pressure vessels in China are summarised in terms of periodic inspection methods,defect handling methods and strength assessment methods.On this basis,specific inspection cases are introduced,and the stress and load conditions of pressure vessels with high operating parameters and high risk factors are analysed in depth,and a parametric finite element model is established for the inspected pressure vessel,and load constraints are set according to its operating condition to obtain the stress distribution of the pressure vessel and find out its weakest location.Based on this,the stress classification method and the ultimate load method were applied to calculate and analyse the strength of the pressure vessel.For the cracks found in the periodic inspection,the finite element analysis method is used to calculate the ultimate load value that the equipment can withstand during operation with defects,in order to provide safety assurance for the future operation of the pressure vessel with defects.In addition,a detailed analysis and comparison of the changes in stress distribution caused by the different shapes of craters formed after the defective grinding is carried out to provide recommendations for the selection of defective grinding shapes to ensure the safe operation of the pressure vessel to the maximum extent.Translated with www.Deep L.com/Translator(free version)For the cracks found in the periodic inspection,the ultimate load value that the equipment can withstand in defective operation is calculated using the FEA method to provide safety assurance for the future operation of the pressure vessel with defects.In addition,a detailed analysis and comparison of the changes in stress distribution caused by the different shapes of craters formed after defect polishing is carried out to provide recommendations for the selection of defect polishing shapes to maximise the safety of defective work on pressure vessels.