Galvanized steel pipes are divided into cold galvanized steel pipes and hot galvanized steel pipes. Cold galvanized steel pipes have been banned, and the state advocates the temporary use of the latter. In 1960s and 1970s, developed countries began to develop new pipes and gradually banned galvanized pipes.
The Ministry of Construction of China and other four ministries and commissions also issued a document explicitly prohibiting galvanized pipes as water supply pipes from 2000. Galvanized pipes are rarely used for cold water pipes in new residential areas, and galvanized pipes are used for hot water pipes in some residential areas. Hot-dip galvanized steel pipes are widely used in fire protection, electric power, highways and other fields.
Welded steel pipe with hot dip coating or electro-galvanized coating on the surface of galvanized steel pipe. Galvanizing can improve the corrosion resistance of steel pipes and prolong their service life. Galvanized pipes are widely used, not only as pipes for conveying general low-pressure fluids such as water, gas and oil, but also as oil well pipes and oil pipelines in petroleum industry, especially as oil heaters for offshore oil fields and chemical coking equipment, as well as pipe piles for trestle bridges and support frames for mine tunnels.
Galvanized pipes are often used, and iron pipes for gas and heating are also galvanized pipes. After being used as a water pipe for several years, a large amount of rust scale is produced in the pipe, and the yellow water flowing out not only pollutes the sanitary ware, but also is mixed with bacteria growing on the unsmooth inner wall. Due to corrosion, the content of heavy metals in water is too high, which seriously harms human health.