Research And Development Of CAPP Software For Pressure Vessels

The design and management of manufacturing process are carried out by the traditional manual method in most companies of steel pressure vessels in China today. It is not suitable for both various market need and the quick development of modern science technology. By using Computer Aided Process Planning (CAPP), the technology ability of the companies and the efficiency of process design could be effectively improve. Aiming at the fabrication specialties of the pressure vessel, a CAPP system for pressure vessels was studied and developed on the basis of widely and intensive investigation into Liyang Yunlong Chemical Equipment Group Co., Ltd.Firstly, the entire structure of the system was put forward based on the investigation and the typical welding and riveting processes in this company were classified and summarized. Then the model of the database was designed and the database system was developed. In the design and development of the CAPP system. Visual Foxpro 6.0 was used to develop the modules and the parameter evaluation procedure was used to realize the automatic production of CAPP parameters. Furthermore, by combining the process design methods in the company with the rules of process design for pressure vessels, the riveting and welding processes of the components were generated automatically or semi-automatically. The types and specifications of pressure vessel components were classified and summarized, The method of classification for the components was proposed to strengthen the capability of the recognition for components data and standard information input in order to provide the foundation for the followed parameters automatic production. The inserting function of OLE technology was used so that the drawings in the form of AutoCAD or BMP could be called into the system. As a result, the design drawings could be inserted in the process files directly and the workload of the designers could be reduced greatly. The emphases were put on the usability of the system and importance of the designers. The database such as product information, components information and craft parameters were established which made fully use of the experience and knowledge of process engineers and would improve the design level, reduce the cost and enhance the production efficiency.The developed system has been used in the practice of the company and provided a helpful tool for the design of the company. The reliability and the practicability of the system have been proved. The development method presented in the paper would also be reference by other companies in the design of welding and riveting processes.