The head is the end cover on the pressure vessel and a main pressure bearing part of the pressure vessel. Its function is sealing. According to the different geometric shapes, it can be divided into spherical, elliptical, saucer shaped, spherical crown shaped, conical shell and flat cap, among which spherical, elliptical, saucer shaped and spherical crown shaped heads are collectively referred to as convex heads. In terms of welding, it is divided into butt welding head and socket welding head. The head is used for various vessel equipment, such as storage tank, heat exchanger, tower, reactor, boiler and separation equipment. Materials include carbon steel, stainless steel, alloy steel, aluminum, titanium, copper, nickel and nickel alloys.
The standard series heads are generally formed by stamping, but the non-standard series heads or heads with large diameter are generally formed by spinning. Compared with stamping, spinning has the advantages of saving mold cost and size can be adjusted according to requirements.