Galvanized pipes, also known as galvanized steel pipes, increase the service life of steel pipes and prevent rusting to a certain extent.
First, Classification of Industrial Galvanized Steel Pipes
1. Hot-dip galvanized steel pipes: This involves reacting molten metal with the iron substrate to create an alloy layer, bonding the substrate and coating. Hot-dip galvanizing first requires pickling to remove iron oxide from the pipe surface, followed by cleaning with an ammonium chloride or zinc chloride solution, before immersion in a hot-dip galvanizing bath. Hot-dip galvanizing produces a more uniform coating with stronger adsorption capacity and a longer service life.
2. Cold-dip galvanized steel pipes: Cold galvanizing, also known as electro-galvanizing, involves a smaller amount of zinc plating, resulting in significantly lower corrosion resistance and a shorter service life compared to hot-dip galvanized steel pipes.
3. Hot-dip galvanized steel pipes: A zinc-iron alloy layer is formed by the reaction of the steel pipe with the galvanizing solution. This alloy layer, along with the pure zinc layer and the steel pipe, is fused together, resulting in strong corrosion resistance.
4. Cold-galvanized steel pipes. The zinc layer and the steel pipe are separate layers. The zinc layer is relatively thin and simply adheres to the surface of the steel pipe. This zinc layer is easily peeled off; therefore, cold-galvanized steel pipes are not permitted as water pipes.
Second, the Main uses of industrial galvanized steel pipes.
Galvanized steel pipes are commonly used for gas and heating systems. While they are also used as water pipes, after a few years, they accumulate a large amount of rust. The resulting yellow water not only stains sanitary ware but also allows bacteria to grow on the inner wall. Rust also causes heavy metal content in the water to exceed standards, further endangering human health. My country’s Ministry of Construction prohibited the use of galvanized steel pipes as water pipes starting in 2000.
Third, Process characteristics of industrial galvanized steel pipes.
The advantage of sulfate zinc plating is that the current utilization rate reaches 100%, and the deposition rate is very fast. However, because the coating crystallization is not fine enough, the deep plating capability is poor, and it is only suitable for pipes and wires with simple geometric shapes. Through process improvements, iron salts were added to the original solution, which not only inherited the advantages of traditional sulfate zinc plating but also enhanced the ability to achieve deep plating. After continuous refinement, the coating grains used on wires and pipes are now finer and shinier than before.
Post time: Dec-09-2025