Head is an indispensable and important part of pressure vessel equipment in petrochemical, atomic energy, food and pharmaceutical industries. Head is the end cover of pressure vessel, and it is a main pressure bearing component of pressure vessel. The function is to seal. The first is to make the top and bottom of the tank pressure vessel. The second is that the pipe ends and is not ready to extend further. Then the pipe is sealed with a head in the form of welding. There are blinds and heads for similar products, but they can be disassembled.