The elliptical head not only has the heat exchange between the powder and the material, but also the heat exchange between the water and the material, but regardless of which medium is different for the inner and outer erosion, washing and scaling of the equipment, such as a complex environment. If the bending resistance to the longitudinal direction of the board is smaller, then wrinkles will occur more arbitrarily. For example, if the head factory has S, Cl- medium, then carbon steel will definitely have more serious erosion, and stainless steel will also produce pitting or erosion between nuclear stress and cause cracking. The occurrence of this situation will result in a shortened operating cycle of the heat exchange equipment, such as an organic elliptical head which is normally required to have a certain thickness. It requires multiple coatings and high temperature baking, so the entire construction process is still complicated. The most important thing is that its temperature resistance is not very good, especially the elliptical head of the oil. It is necessary to use high-pressure steam for purging during each inspection, so it is easy to cause damage to the coating. In the heading factory, if the temperature of the slab material is not uniform during heating, the gap between the mold and the lower mold corner is too large, and the pressure edge is uneven, the bulge or wrinkles may be caused. The head is in the ellipsoidal where it needs to be smooth and continuous through the curvature of the line, so the stress distribution must be sufficiently uniform. Moreover, the elliptical head is much less in depth than the hemispherical, and it is easier to punch and form. It can be said that it is one of the more commonly used heads in medium and low pressure containers.