Head

Head is an element used to close the end of a container and isolate its internal and external media, also called end cap.  The head of a cylindrical vessel is usually a revolving shell.  According to the shape of the head surface, it can be divided into convex, conical, flat and combined shapes.  Convex heads refer to heads with convex outer surfaces, such as hemispherical, elliptical, dished and flangeless spherical heads.  Some gas cylinders adopt combined bottom heads with convex surfaces inward, which can not only ensure strength, but also meet the requirements of safe use.