The ferrule type has the characteristics of secure connection, high pressure resistance, good temperature resistance, sealing and repeatability, easy installation and maintenance, safe and reliable work, etc. The working principle of the ferrule type is to insert the copper tube into the ferrule, use the ferrule nut to lock it against the ferrule, cut into the tube and seal it. It is connected to the copper tube without welding, which is conducive to fire prevention, explosion-proof and overhead work, and eliminates the disadvantages caused by inadvertent welding.