The presentation of galvanized steel pipe once brought us convenience, but with the development of the times, galvanized steel pipe has been gradually screened out of the stage of history. But do you know what galvanized steel pipe is? What's the history of galvanized steel pipe? What's the theoretical weight table of galvanized steel pipe? Let's learn about galvanized steel pipe with a small editor.
What is galvanized steel pipe
Galvanized steel pipes are divided into cold galvanized pipes and hot galvanized pipes. At the beginning, galvanized steel pipes were used as water pipes. After a few years, a large number of rust scales were produced in the pipes. The yellow water not only polluted the sanitary wares, but also was mixed with the bacteria growing in the uneven inner wall. The corrosion caused the high content of heavy metals in the water, seriously endangering human health. Therefore, in the 1960s and 1970s, developed countries began to develop new pipes, and gradually banned galvanized steel pipes. In China, galvanized steel pipes have been banned since 2000. Nowadays, galvanized steel pipes are rarely used in most new communities, but some are still using galvanized steel pipes.
Hot dip galvanized steel pipe
The hot-dip galvanized steel pipe is an alloy layer formed by the reaction of molten metal and iron matrix, so that the matrix and coating are combined. Hot dip galvanizing is to pickle the steel pipe, remove the iron oxide on the surface of the steel pipe, and then send it to the solution tank of ammonium chloride or zinc chloride or the mixed solution tank of ammonium chloride and zinc chloride for cleaning, and then send it to the hot dip galvanizing tank. Hot dip galvanizing has the advantages of uniform coating, strong adhesion and long service life. The matrix of hot-dip galvanized steel pipe reacts with the molten bath in a disordered physical and chemical way, forming a zinc iron alloy layer with corrosion resistance and tight structure. The alloy layer is integrated with pure zinc layer and steel pipe matrix, which has strong corrosion resistance.
Cold galvanized steel pipe
The cold galvanized steel pipe is galvanizing, the amount of galvanizing is very small, as long as 10-50g / m2, its corrosion resistance is much worse than the hot galvanized steel pipe. In order to ensure the quality, the regular galvanized pipe manufacturers generally do not choose galvanizing, as long as those small enterprises with small planning and old equipment will choose galvanizing, and their prices are naturally cheaper. The galvanized layer of cold galvanized steel pipe is electroplated layer, and the zinc layer is separated from the steel pipe substrate. The zinc layer is thin and simply attached to the steel pipe matrix, which is easy to fall off and has poor corrosion resistance. The Ministry of construction has already formally selected the backward cold galvanized rigid pipes, which are forbidden to be used as water supply and gas pipes. It is also strictly prohibited to use cold galvanized steel pipes as water supply pipes in new residences.
Use of galvanized steel pipe
Welded steel pipe with hot dip or electro galvanized coating on the surface of galvanized steel pipe. Galvanizing can increase the corrosion resistance of steel pipe and extend its service life. Galvanized steel pipes are widely used, not only as pipelines for water delivery, gas, oil and other general low-pressure fluids, but also for oil well pipes and oil pipelines in petroleum industry, especially in offshore oil fields, oil heaters, condensing coolers, coal distillate wash oil exchangers for chemical coking equipment, trestle pipe piles, support frame pipes for mine tunnels, etc. Hot dip galvanized steel pipe is widely used in all kinds of modern manufacturing industries.