Hygienic living joints can be widely used in pipelines with different calibers and can also be used for water meters and valves. Due to the adoption of the inheritance structure, the pipeline joint reduces the cost, installation, use, and maintenance extremely convenient, and has extremely high leak resistance. There are mainly nuts, cloud heads, and flat connection. The pipeline connecting parts processed by the metering of the round steel or steel ingot mold. Its connection form is divided into welding and thread connection. "Live connecting", the thread connection is to connect the steel tube into the threaded hole. Therefore, it is called the "threading connector", and the main manufacturing standard is Asme B16.11, MSS SP 83.