Many styles and wide applications 1) According to the pressure level, it can be divided into: low pressure vessel, medium pressure vessel, high pressure vessel and ultra high pressure vessel. 2) According to the containing medium: non-flammable, non-toxic; flammable or toxic, highly toxic. 3) Divided into different functions in the process: ①Reaction container: a container used to complete the physical and chemical reactions of the medium. ② Heat exchange container: a container used to complete the conversion and exchange of the medium. ③Separation container: a container used to complete medium quality exchange, gas purification, solid, liquid, and gas separation. ④ Storage and transportation container: a container used to contain liquid or gas materials, storage and transportation media, or to balance and buffer the pressure. 4) In order to implement scientific management and safety supervision and inspection more effectively, China’s “Pressure Vessel Safety Supervision Regulations” classifies pressure vessels into three categories based on working pressure, medium hazards and their role in production. Different regulations have been made in the design, manufacturing process, and inspection items, content and methods of pressure vessels. The pressure vessel has implemented the import product safety and quality license system, and the products that have not obtained the import safety and quality license are not allowed to be imported. Premium quality