What is Galvanized Pipes

galvanized steel pipes are divided into cold Galvanized steel pipes and hot galvanized steel pipes. Cold galvanized steel pipes have been banned, and the latter has been advocated by the state for temporary use. In the 1960s and 1970s, developed countries began to develop new types of pipes, and have banned galvanized pipes. China's Ministry of Construction and other four ministries and commissions also issued a document explicitly banning galvanized pipes as water supply pipes from 2000. Galvanized pipes are rarely used in cold water pipes of new residential areas, and some residential hot water pipes use galvanized pipes. Hot dip galvanized steel pipe has a wide range of applications in fire, electric power and highway.

Type of Galvanized Pipes

1. Hot Dip galvanized pipes.

The hot-dip galvanized pipe is formed by the reaction of molten metal and iron substrate to produce an alloy layer, so that the substrate and coating are combined. Hot-dip galvanizing is to pickle the steel pipe first. In order to remove iron oxide on the surface of the steel pipe, after pickling, it should be washed with ammonium chloride or zinc chloride aqueous solution or a mixed aqueous solution of ammonium chloride and zinc chloride, and then sent to a hot-dip galvanizing tank. Hot-dip galvanizing has the advantages of uniform coating, strong adhesion and long service life. A complex physical and chemical reaction occurs between the substrate of the hot-dip galvanized steel pipe and the molten pool, thereby forming a dense zinc-iron alloy layer with corrosion resistance. The alloy layer is integrated with the pure zinc layer and the steel pipe substrate, so it has strong corrosion resistance.

2. Cold galvanized pipes.

Cold galvanized pipe is electro-galvanized, the amount of galvanizing is very small, only 10-50g/m2, and its corrosion resistance is much worse than that of hot-dip galvanized pipe. The galvanized pipe manufacturer of the track, in order to ensure the quality, the large purchase of JDG threading pipe does not use electro-galvanizing (cold plating). Only small companies with small equipment and outdated equipment use electro-galvanized steel, of course, their prices are relatively cheaper. The Ministry of Construction has officially laid down the cold-dip galvanized pipes with backward technology, and the cold-dip galvanized pipes are not allowed to be used as water and gas pipes. The galvanized layer of cold-dip galvanized steel pipe is an electroplated layer, and the zinc layer is independently layered with the steel pipe substrate. The zinc layer is relatively thin, and the zinc layer is easily attached 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.

Material of Galvanizing Product

The raw material of galvanized parts is generally low carbon steel (carbon content is 0.10%-0.20%), for special purposes of galvanized materials, available carbon steel or high carbon steel as steel parts.

Production procedure

Technological process is: the clarinet, alkaline cleaning, washing, pickling, rinse, leaching agent, drying, hot dip galvanized - - within the outer wind - air cooling, water cooling, passivation, water rinse, inspection, weighing, warehousing.

Application

Hot-dip galvanized steel pipes are widely used in construction, machinery, coal mines, chemicals, electric power, railway vehicles, automobile industry, highways, bridges, containers, sports facilities, agricultural machinery, petroleum machinery, prospecting machinery, greenhouse construction and other manufacturing industries.

Galvanized steel pipe is a welded steel pipe with a hot-dip or electro-galvanized layer on the surface. Galvanizing can increase the corrosion resistance of steel pipes and prolong their service life. Galvanized pipes are widely used. In addition to being used as pipeline pipes for general low-pressure fluids such as water, gas, and oil, they are also used as oil well pipes and oil pipelines in the petroleum industry, especially offshore oil fields, and oil heaters and condensation pipes for chemical coking equipment. Pipes for coolers, coal distillation washing oil exchangers, trestle piles, and support pipes for mine tunnels, etc.