Galvanized pipes have different classifications according to different use sites. The following galvanized pipes will summarize the standard classification of galvanized pipes for everyone, so that everyone can have a better understanding of them:
In order to improve the corrosion resistance of steel pipes, general steel pipes (black pipes) are galvanized.
Galvanized steel pipe is divided into two types: hot-dip galvanized and electric steel zinc. The hot-dip galvanized galvanized layer is thick and the cost of electric galvanized is low.
Oxygen blowing welded pipe: It is used as oxygen blowing pipe for steel making, generally small-diameter welded steel pipe, with eight specifications ranging from 3/8 inch to 2 inch. Made with 08, 10, 15, 20 or Q195-Q235 steel strip. In order to prevent corrosion, some are aluminized.
Galvanized steel pipes are divided into cold galvanized pipes and hot galvanized pipes. The former has been banned, and the latter has been advocated by the state to be temporarily available.
The hot-dip galvanized pipe is to make the molten metal react with the iron matrix to produce an alloy layer, so that the matrix and the coating are combined. Hot-dip galvanizing is to pickle the steel pipe first. In order to remove the iron oxide on the surface of the steel pipe, after pickling, it is cleaned in the tank of ammonium chloride or zinc chloride aqueous solution or mixed aqueous solution of ammonium chloride and zinc chloride, and then sent to the in the hot dip bath. Hot-dip galvanizing has the advantages of uniform coating, strong adhesion and long service life.
Hot-dip galvanized pipe: complex physical and chemical reactions occur between the steel pipe matrix and the molten plating solution to form a corrosion-resistant zinc-iron alloy layer with a tight structure. The alloy layer is integrated with the pure zinc layer and the steel tube substrate. Therefore, it has strong corrosion resistance.
Cold galvanizing is electro-galvanizing. The amount of galvanizing is very small, only 10-50g/m2. Its corrosion resistance is much different than that of hot-dip galvanized pipes. In order to ensure the quality, most regular galvanized pipe manufacturers do not use electro-galvanizing (cold plating). Only those small enterprises with outdated equipment use electrogalvanizing, and of course their prices are relatively cheap. At present, the Ministry of Construction has officially issued a document to eliminate cold galvanized pipes with backward technology, and cold galvanized pipes are not allowed to be used as water and gas pipes in the future.
Cold galvanized steel pipe: The zinc layer is an electroplating layer, and the zinc layer is independently layered with the steel pipe substrate. The zinc layer is thin, and the zinc layer simply adheres to the steel pipe substrate and is easy to fall off. Therefore, its corrosion resistance is poor. In newly built houses, it is forbidden to use cold galvanized steel pipes as water supply pipes.
In the above content, Beijing galvanized pipe has made a detailed introduction to the classification of galvanized pipe. I believe that everyone has a certain understanding of this through these contents, and I hope these contents can help everyone.