Galvanized steel pipes are divided into cold-dip galvanized steel pipes and hot-dip galvanized steel pipes. The former has been banned, and the latter has been advocated by the country to be temporarily used. Hot-dip galvanized steel pipe. Hot-dip galvanizing pipe reacts molten metal with an iron matrix to produce an alloy layer, thereby combining the matrix and the coating. Hot-dip galvanizing is to pickle the steel pipe first. To remove the iron oxide on the surface of the steel pipe, after pickling, it is cleaned in an aqueous solution of ammonium chloride or zinc chloride or a mixed aqueous solution of ammonium chloride and zinc chloride and then sent to a hot dip plating tank. Hot-dip galvanizing has the advantages of uniform coating, strong adhesion, and long service life. Cold galvanized steel pipe. Cold galvanizing is electro-galvanizing. The amount of galvanizing is very small, only 10-50g/m2. Its corrosion resistance is much worse than that of hot-dip galvanized steel pipes. Regular galvanized steel pipe manufacturers, to ensure quality, do not use electro-galvanizing (cold plating). Only small businesses with small-scale and old equipment use electro-galvanizing, and of course, their prices are relatively cheaper. At present, the Ministry of Construction has officially issued a notice to eliminate cold-galvanized steel pipes with backward technology. In the future, cold-galvanized steel pipes are not allowed to be used as water and gas pipes.
Post time: Jan-19-2024