Special galvanized pipe for outlet
Short Description:
Galvanized pipe, also known as galvanized steel pipe, is divided into hot-dip galvanizing and electro galvanizing. The hot-dip galvanizing layer is thick and has the advantages of uniform coating, strong adhesion and long service life. The cost of electro galvanizing is low, the surface is not very smooth, and its corrosion resistance is much worse than that of hot-dip galvanized pipe.
Hot dip galvanized steel pipe
Complex physical and chemical reactions occur between the steel pipe matrix and the molten plating solution to form a corrosion-resistant zinc ferroalloy layer with compact structure. The alloy layer is integrated with the pure zinc layer and the steel pipe matrix. Therefore, it has strong corrosion resistance.
After the development from 1960s to 1970s, the product quality of hot-dip galvanized steel pipe has been greatly improved. From 1981 to 1989, it was continuously rated as high-quality product of the Ministry of metallurgy and national silver award. The output has also increased for many years. The output was more than 400000 tons in 1993 and more than 600000 tons in 1999. It is exported to Southeast Asia, Africa, the United States, Japan, Germany and other countries and regions. Hot dip galvanized pipes are mostly used as water transmission pipes and gas pipes, with common specifications of + 12.5 ~ + 102 mm. Since the 1990s, due to the state’s attention to environmental protection and more and more strict control over high polluting enterprises, the “three wastes” produced in the production of hot-dip galvanized pipes are difficult to solve, coupled with the rapid development of stainless steel welded pipes, PVC pipes and composite pipes, as well as the promotion of chemical building materials and the restriction of the use of galvanized steel pipes, The development of hot-dip galvanized welded pipe was greatly restricted and limited, and the development of hot-dip galvanized welded pipe was slow.
Cold galvanized steel pipe
The zinc layer is an electroplating layer, which is separated from the steel pipe matrix. The zinc layer is thin, and the zinc layer is simply attached to the steel pipe matrix, which is easy to fall off. Therefore, its corrosion resistance is poor. In new houses, it is forbidden to use cold galvanized steel pipes as water supply pipes.
