The use of galvanized steel pipes

Hot-dip galvanized steel pipe is widely used in construction, machinery, coal mine, chemical industry, electric power, railway vehicles, automobile industry, highways, Bridges, containers, sports facilities, agricultural machinery, petroleum machinery, prospecting machinery and other manufacturing industries.

Galvanized steel pipe Welded steel pipe with hot dip plating or electrogalvanized coating on the surface. Galvanizing can increase the corrosion resistance of the steel pipe and extend the service life. Galvanized pipe has a wide range of uses, in addition to the pipeline pipe for water, gas, oil and other general low pressure fluids, it is also used as the oil well pipe, oil pipeline, especially in the oil field of the petroleum industry, the oil heater, the condensing cooler of the chemical coking equipment, the tube for the coal distillation and washing oil exchanger, and the pipe for the trestle pipe pile and the support frame of the mine tunnel.

Hot-dip galvanized pipe is a kind of pipe with composite structure formed by the reaction of molten metal and iron matrix to produce alloy layer, so that the matrix and coating are combined to form a composite structure. In the manufacturing process, the steel pipe first needs to be pickled to remove iron oxide impurities on the surface. The tubes are then cleaned by dipping them into a tank of ammonium chloride, zinc chloride, or an aqueous solution of ammonium chloride and zinc chloride to remove residual iron oxide and other impurities. Finally, the cleaned steel pipe is sent into the hot dip plating tank, and a uniform and strong adhesion zinc-iron alloy layer is formed on the surface of the steel pipe by heating and electrolyte.

Hot-dip galvanized steel pipe has the following advantages: uniform coating, strong adhesion, long service life and so on. These advantages make hot-dip galvanized steel pipe in a variety of industrial fields have been widely used, such as construction, machinery, electric power and other industries.

Cold galvanized pipe is a pipe produced by electric galvanizing process, and its galvanizing amount is less, only 10-50g/m2. Due to the small amount of galvanizing, the corrosion resistance of cold galvanized pipes is much worse than that of hot galvanized pipes. In order to ensure quality, most of the regular galvanized pipe manufacturers do not use electric galvanizing (cold plating). Only those small enterprises with obsolete equipment use electric galvanizing, of course, their prices are relatively cheap. The Ministry of Construction has formally announced the elimination of cold galvanized pipes with backward technology, and it is not allowed to use cold galvanized pipes as water and gas pipes.

When selecting galvanized pipe, it is necessary to pay attention to its weight coefficient, nominal wall thickness, coefficient parameters, as well as the grade of steel, test pressure value and other parameters. In addition, it is also necessary to refer to the relevant national standards and size standards, such as GB/T3091-2015 welded steel pipe for low pressure fluid transport, GB/T13793-2016 straight seam electric welded steel pipe, GB/T21835-2008 welded steel pipe size and weight per unit length.