A container refers to a basic device that is used to contain materials and is mainly a shell. It is often used as the enclosure of storage equipment or other chemical equipment. It is mainly composed of shell, head, connecting pipe, flange and support. The basic requirements for the container are: to meet the process needs; to ensure safe operation, including sufficient strength, rigidity and sealing; corrosion resistance and a certain service life; easy to manufacture, install, maintain and use; low cost and material saving, In particular, it is necessary to save precious materials such as stainless steel and non-ferrous metals.