Welding Process Design Of Butterfly Valve

The valve has been playing an important role in lots of fields,such as chemistry,energy,water,etc. And the large butterfly valve is used more and more widely because of itsexcellent performance. Though China has built a complete valve production system, in thewelding of large butterfly valve, it still faces the problems of unstable quality andinefficiency，which are caused by the welding characteristics, for example, vast structure,thick plank stuff and heavy workload. Plate welding process mainly focuses on theoptimization of process parameters, the improvement of joint forms and the development ofnew welding methods.As research subjects, the DN3400butterfly valve produced by the cooperativecompany, is welded by Q235B, WCB and304. The welding performance of WCB and304is poor. So the flaw and deformation will be more likely to appear in the circumjacent weldbeads of bearing support, cylinder rings and obturating ring. In addition, due to repeatedheating, the valve body will produce deformation in the axial and radial distortion afterwelding. The measurement shows that the deformation in the axial is8.51mm and theroundness of oval deformation is8mm. And it is accord with the result ofSpraragen-Fttinger Formula.According to those problems, this thesis optimizes the existing processes by changingthe form of joints, using anti-deformation, adjusting the welding sequence, using DSAWtechnology. In addition, we design a welding robot system and corresponding operatingprocess based on the TA1800robot produced by Tangshan Panasonic...