Steel-plastic composite pipes are connected through threads. Galvanized metal pipes tend to be linked through threads, additionally the exterior of this galvanized layer and also the revealed threads which can be damaged during the threading should really be addressed alongside anti-corrosion therapy.Welding is suitable concerning non-galvanized steel pipelines. It is mostly employed for concealed pipelines to pipes alongside larger diameters, and it is usually utilized in high-rise buildings. Copper pipe connection could adopt great joint as welding. As Soon As The pipeline diameter try less than 22mm, socket otherwise sleeve welding is used.