Double (high) tank plates are marked first, then rounded, welded, painted and baked, and then divided by a divider. This can double the output. Some welding machines line the tank plate on a single marking machine, while others directly install marking accessories on the rounded part of the welding machine, which makes less marking in the process of separate feeding. The depth of marking is 2/3 of the thickness of tinplate, and it can be broken just twice to be qualified. The marking position should be in the middle of the double tank plate, and the error should not exceed 0.1mm. The purpose of flanging is to form a body hook. Flanging of tank can be divided into two methods: die-pressing flanging and spinning flanging. Comparatively speaking, the spinning flanging technology is more advanced, but the die manufacturing of spinning flanging is more complicated. The flanging size of the tank body is mainly the flanging width. Generally, the flanging width of tanks with internal diameters of φ52.3mm and φ65.3mm is 2.50±0.20mm；; ; The inner diameter of the tank is φ72.9— 105. 1mm, and the flanging width is 2.70±0.20mm；; ; The flanging width of the tank with internal diameter φ 153mm is 3.2±0.20mm, and it is also required that the tinplate will not be scratched during flanging, and the welded part will not crack, and there will be a certain angle after flanging. When the height of the tank is high, in order to reduce the thickness of iron and enhance the strength of the tank, reinforcing ribs are generally rolled on the tank. Reinforcing ribs of pressure tank The function of reinforcing ribs of pressure tank is to increase the strength of tank, so as to improve the ability of container to resist pressure changes inside and outside the tank. When the tank container is large or high in handling, pressing the reinforcing ribs on the tank can make the container have enough strength to ensure that the tank will not be deformed after sterilization and cooling. At the same time, due to the improvement of container compressive strength, the thickness of tinplate can be appropriately reduced to reduce the obvious consumption of container materials.