Galvanized steel pipes are divided into cold galvanized steel pipes and hot-dip galvanized steel pipes. Cold galvanized steel pipes have been banned. In the 1960s and 1970s, developed countries in the world began to develop new types of pipes and gradually banned galvanized pipes. Four ministries and commissions including the Ministry of Construction of China have also issued a document stating that galvanized pipes are prohibited from being used as water supply pipes since 2000. Galvanized pipes are rarely used for cold water pipes in newly built communities, and galvanized pipes are used for hot water pipes in some communities. Hot-dip galvanized steel pipes have a wide range of applications in fire protection, power and highways. Galvanized steel pipe is a welded steel pipe with a hot-dip galvanized or electro-galvanized layer on the surface. Galvanizing can increase the corrosion resistance of steel pipes and prolong the service life. Galvanized pipes are widely used. In additio...