A general pipe is a pipe that conveys a working fluid in a hydraulic system. The pipeline is a properly arranged piping system relative to the pipeline. Because of the flexibility of the pipeline, pipelines are often used in liquid-driven mechanical equipment such as hydraulic systems. Since the various parts of the automobile air conditioner are generally dispersedly installed in various parts of the automobile, the automobile air conditioning duct is like a human blood vessel, and is responsible for connecting these dispersed components, thereby enabling a complete automobile air conditioning system to work in an orderly manner. Automotive air conditioning ducts are usually made up of aluminum tubes, air conditioning hoses and other piping accessories.