As a high-efficiency heat exchange equipment, the all-welded plate heat exchanger combines the advantages of plate-type heat exchangers and shell-and-tube heat exchangers. On the one hand, it retains the high efficiency and compact structure of the plate heat exchanger. The high temperature and high pressure resistance of the shell-and-tube heat exchanger is the most ideal equipment to replace the shell-and-tube heat exchanger in some special heat exchange processes. In the processes of heating, cooling, condensation, evaporation, etc. in the fields of chemical industry, petroleum, power, metallurgy, etc., all-welded plate heat exchangers have been widely used.