The steel tube can be classified according to the rolling process, whether there are joints and the shape of section. According to the rolling technology classification, the steel pipe can be divided into hot-rolled steel pipe and cold rolled steel pipe; According to whether there is seam classification, steel pipe is divided into seamless steel pipe and welded steel pipe, Steel Pipe which are commonly used welded pipe types can be divided into high-frequency welded pipe, straight seam submerged arc welded pipe, spiral submerged
The steel tube has several advantages:
First, the surface of the steel tube is used to prevent the more durable, Steel Pipe not faster than the oxidation, will not be formed in the steel pipe white rust;
Second, the full protection of steel pipe, through heating the steel tube each part of the galvanized, concave and convex place has been protected;
Third, with anti-corrosion wear-resistant features, so that the use of steel pipe longer
Four, as already outside the steel tube has been galvanized, Steel Pipe thus eliminating the oil or paint outside the time, construction is more convenient;
Five, galvanized steel pipe is 39 days will not be frozen crack, especially for the northern cold environment!
Steel tube, as the name implies, is made of steel pipe, commonly used A3 steel, suitable for conveying water, compressed gas, condensed water and other media and used as heating pipe. At present, the common pipe in the market mainly consists of steel pipe and seamless steel pipe.
(1) Welded steel pipe
Welded steel pipe also known as water, gas pipe, generally used A3 steel, Steel Pipe suitable for conveying water, compressed gas, condensate and other media and used as heating pipe. According to the surface condition of the steel pipe, welded steel pipe can be divided into galvanized welded steel pipe and galvanized welded steel pipe.
In addition, according to the pipe end state of the pipe, there are two kinds of pipe end with threaded steel pipe and pipe end with no threaded steel pipe. Non-galvanized pipe without thread length of 4,112 m, Steel Pipe galvanized pipe with threaded and galvanized pipe is generally 419 m, pipe end thread is tapered pipe thread, according to wall thickness can be divided into thin-walled pipe, common tube and thickened tube three kinds.
In the pipeline project use, generally does not use the thin-walled steel tube, the general ordinary tube withstands the pressure in 2MPa, but the thickened tube should be able to withstand 3 MPa pressure. Steel Pipe Welded steel pipe material is soft, easy to cut and thread processing, welding performance is good. However, galvanized steel pipe because of the corrosion of zinc peel in the welding site, it is generally not recommended to use welding connection. Steel Pipe The weight of the welded steel pipe is the theoretical weight of the galvanized steel pipe and the theoretical weight of the galvanized steel pipe, which still needs to be increased by 3% 6%.
For welded steel pipes, quality inspection shall be conducted in accordance with current national or ministerial standards. In addition to their materials, models, specifications should be in line with the design requirements, but also to check their appearance quality. The inspection items include defects such as crack, slag, folding, heavy skin, and the degree of corrosion sag. Steel Pipe Thread-connected pipe also need to check the thread sealing surface and thread roughness and smoothness, for galvanized steel pipe should pay attention to whether the zinc peel off.
Welding pipe in storage must pay attention, can not be simply placed in the outdoor, but should be stored in the room, at least to be stored in the shed, to avoid sun and rain, Steel Pipe and not directly on the wet ground, to prevent serious corrosion. Pipe end with threaded pipe, both ends need to be with a hoop or pipe cap to protect the thread from damage.
(2) Seamless steel tube
Seamless steel tube is through the hot cylindrical steel in the general direction of perforation, it because of uniform material, a good corrosion resistance, high strength, Steel Pipe can be transported with pressure media, such as steam, superheated water and flammable explosive, toxic substances. Therefore, it is widely used in engineering pipelines. Seamless steel tubes are generally used to transport pressurized media, such as steam, superheated water and flammable explosive, toxic substances.