In the design and manufacture of pressure vessels for petrochemical equipment, conical heads are commonly used. When the half-angle of the cone tip is greater than or equal to, it is required to use a flanged cone head with a transition arc at the large end to reduce the stress on the connecting edge of the cylinder and the cone to improve the pressure state of the pressure vessel and ensure the safe operation and use of the equipment. In the manufacturing process of petrochemical pressure vessels, the ideal processing and forming process is to first roll into a cone shape, and then use a mold to perform integral hot stamping of the transition arc area. However, the size of the flanged cone of the manufactured equipment is limited by the capacity of the processing equipment of the enterprise, which cannot be achieved. Now introduces a method of subsection forming and group welding, that is, the cone part can be rolled and grouped by conventional manufacturing methods. And the folding section is divided into stamping and group welding forming, and finally the two sections are grouped and welded to form a large diameter folding cone head technology and die design technology.

　　Mold manufacturing material selection

　　Due to the use of hot press forming, the load is relatively reduced. For split stamping, it is better to use a casting die, or a steel plate tailor-welded to make the die. The mold material can meet the requirements for cast iron.

　　Wood mold and modeling method of casting die

　　Mold wood mold and sand mold manufacturing method, if the overall wood mold is made according to the drawings, firstly, the cycle is long, and the second is the consumption of materials. For this reason, the "bottom-type horizontal profiling method" is adopted.

　　Sand moulding

　　Firstly, the arc surface of the bottom plate is placed in the sand on the floor, and then the scraper is used on the template to scrape in the cavity shape. Pay attention to move within the scribe line of the equal angle to scrape out the curved sand. After a sand mold is made, the wood mold is sent for restructuring, and the inverted form is replaced, and then another sand mold can be made.

　　For the manufacture of large flanged cone heads, the partial forming group welding method is adopted, that is, the cone part is rolled and grouped according to the conventional process. The folding section is formed by split stamping and group welding, and finally the two sections are grouped and welded to form a large diameter folding cone head technology and die design technology, which uses existing processing equipment to form a large folding cone seal The best effective way to head.