The head is a part of the container and is connected to the cylinder in a welding way. According to the different shape, can be divided into spherical, oval, dish shaped, spherical, conical shell and cover several, including spherical, oval, dish shaped, spherical head is also called convex head. The welding is divided into butt welding heads and socket welding heads. Used for various containers, such as tanks, heat exchangers, towers, reactors, boilers and separation equipment, etc.. Material has carbon steel (A3, 20#, Q235, Q345B, 16Mn, etc.), stainless steel (304, 321, 304L, 316, 316L, etc.), alloy steel (15Mo3, 15CrMoV, 35CrMoV, 45CrMo), aluminum, titanium, copper, nickel and nickel alloy, etc..
The head is the main compression component of the boiler and pressure vessel, and its structure and shape design are reasonable, which affects the safety of the boiler and pressure vessel. Therefore, the shape of various heads is limited in the relevant codes