The Study Of Stress Analysis And Structure Optimization Of High Strength Pipeline Integral Type Insulation Joint

With the development of petroleum industry,pipeline industry technical level has been rapidly improved,which the use of the insulation joint has a complete trend of replacing insulation flange.Although the pipeline insulation joint has widely applied in oil and gas industry pipeline,the theory study of the high strength pipeline insulation joint has not been enough attention and further development of the system,especially for the shape study and the influence of preloading amount of sealing and stress of sealing device,and the nonlinear problems caused by various size parameters of joint.This topic adopts finite element software ANSYS WORKBENCH,analyzing the stress,optimizing the structure of the integral insulation joint,including the study of sealing device and the size optimization research of the simplified integral insulation joint.Research on sealing device is mainly to determine the reasonable preloading amount,and then the reasonable preloading amount is applied to the simplified integral type insulation joint,and then further optimization.Under the condition of guaranteeing the sealing and strength of the joint,the joint size of affecting joint's strength,quality and sealing is designed to extend the time of use,operation safety and more economy.After analysis,final joint preloading amount to 1mm.In this case,founding trapezoidal groove seal effect is better than e the sealing effect of rectangular groove.When the preloading amount is zero,rectangular groove can be sealing effect,but trapezoidal cannot be sealing,so the shape of the joint sealing device is finally determined to rectangular groove.Contact pressure of rectangular groove is increasing with the increasing of preloading,the quantity relationship between the contact pressure of rectangular and the preloading is linear function.Contact pressure of trapezoidal groove increase rise sharply after increasing slowly along with the increasement of preloading amount,and the quantity relationship between the contact pressure of trapezoidal groove and the preloading is Gaussian function.The maximum equivalent stress of rectangular groove and trapezoidal groove rise sharply after decreasing slowly along with the increasement of preloading amount.The quantity relationship between the maximum equivalent stress of rectangular groove and trapezoidal groove and thepreloading is cubic function.Joint size optimization results: insulation ring height is 40.715mm;weld height is35.02mm;Left flange thickness is 90.068mm;Insulation sealing packing length 1 is71.645mm;Insulation sealing packing length 3 is 117.187 mm.Applying the mechanics makes a theoretical modeling for the optimization solution in the end.The theoretical solution compares with the finite element solution,proving that the finite element solution is reliable.