description of the hot galvanizing production line and the products Hot galvanized products are made of steel pipes which are pickled with acid to remove the ferric oxide, and then the steel pipes are dried and dipped into a melted zinc pot, the melted zinc is blown onto the internal and external surfaces of the pipes to form a layer of zinc, which is purified at last . the water supply pipelines, sewage pipes, fire fighting pipes ,gas pipelines, cold and heat supply pipelines, compressed air pipes, and used in water supply projects, conduit pipes in telecommunication, electric and building industry.