Plastic-coated steel pipes, also known as plastic-coated pipes, steel-plastic composite pipes, and plastic-coated composite steel pipes, are based on steel pipes. A layer of plastic anti-corrosion layer or plastic anti-corrosion layer is fused to the inner surface of the steel pipe (bottom pipe) through spraying, rolling, dipping, and suction processes. A steel-plastic composite steel pipe with a plastic anti-corrosion layer fused to the inner and outer surfaces.

Galvanized steel pipes are divided into cold-dip galvanized steel pipes and hot-dip galvanized steel pipes. Cold-dip galvanized steel pipes have been banned, and the latter has been advocated by the country for temporary use. In the 1960s and 1970s, developed countries in the world began to develop new pipes and gradually banned galvanized pipes. China's Ministry of Construction and four other ministries and commissions have also issued documents clarifying that galvanized pipes will be banned as water supply pipes starting in 2000. Galvanized pipes are rarely used in cold water pipes in newly built communities, and hot water pipes in some communities use galvanized pipes. Hot-dip galvanized steel pipes are widely used in fire protection, electric power, and highways.