Research on Welding Process for Branch Pipe Expansion of "Guohe No.1" Main Steam Safety Valve
The branch pipe expander of the"Guohe No.1"main steam safety valve is a key equipment for innovatively solving the noise problem during the operation of nuclear power plants.Its material is SA-182 Gr.F11 Cl.2,which is welded from the upper and lower forgings.The overall structure is a cylindrical container with small ends and large middle,but the weld does not have the condition for back gouging.This article focuses on the structural characteristics of branch pipe expander,and designs a reasonable single-sided welding double-sided forming groove form.In combination with the requirements of weld quality control and welding efficiency,a welding scheme of argon arc backing welding and manual welding filling is selected for welding.Corresponding welding specification parameters have been developed based on the characteristics of the materials,and their performance meets the design requirements.After technological verification,the difficulties of single-sided welding and double-sided forming,as well as welding deformation control,have been solved successively,and the batch engineering application of branch pipe expander has been achieved through reasonable tooling settings.After implementation,a total of 14 pieces of expanded branch pipes in all batches have been qualified after the non-destructive test in one time,and the weld quality met the design requirements.The manufacturing quality was stable and the cycle was controllable,indicating fully overcome the manufacturing difficulties of branch pipe expander.
main steam safety valve branch pipe expandersingle-sided welding and double-sided formingmechanical properties
万方数据
