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Steel Knowledge Encyclopedia-Definition and Classification of Steel Pipe

Definition and classification of a steel pipe (1)


  Steel is a hollow steel bar, a large number of pipes for transporting fluids, such as oil . Natural gas . Water . Gas . Steam, etc. In addition, we engaged in bending . Torsional strength, light weight, so it is widely Used in the manufacture of mechanical parts and engineering structures. Also used in the production of conventional weapons . Barrel . Shells and so on.


  Classification of steel pipes: steel pipes are divided into two categories: seamless steel pipes and welded steel pipes (seam pipes). Can be divided by the cross-sectional shape and a tube shaped tube, circular steel is widely used, but there are some square . Rectangle . Semicircular . Hexagon . Equilateral triangle . Octagon shaped steel tubing. For steel pipes subjected to fluid pressure, hydraulic tests must be carried out to check their pressure resistance and quality, and no leakage will occur under the specified pressure . Wetting or expansion is qualified, and some steel pipes are also subject to crimping tests according to standards or requirements of the buyer. . Flaring test . Flattening test, etc.


  Seamless steel pipe: seamless steel ingot is made of perforated or solid tube through the capillary, and then hot-rolled . Rolled or cold call is made. The specifications of seamless steel pipes are expressed in millimeters of outer diameter * wall thickness. Seamless steel pipes are divided into two types: hot-rolled and cold-rolled (dial) seamless steel pipes. Hot-rolled seamless steel pipe generally sub, low . Medium pressure boiler pipe, high pressure boiler steel . Steel pipe . Stainless steel pipe . Petroleum cracking tubes . Geological steel and other steel and the like. Cold-rolled (dial) in addition to seamless steel pipe generally sub . Low-pressure boiler steel . High pressure boiler steel . Steel pipe . Stainless steel pipe . Oil cracking pipe . Other steel, further comprising a thin-walled carbon steel . Alloy thin steel . Stainless thin-walled steel pipe . Special-shaped steel pipe. The outer diameter of the hot-rolled seamless pipe is generally greater than  32mm , and the wall thickness is  2.5-75mm . The diameter of the cold-rolled seamless pipe can be up to  6mm , the wall thickness can be up to 0.25mm , and the outer diameter of the thin-walled pipe can be up to  5mm and the  wall thickness is less than 0.25mm , cold rolling has higher dimensional accuracy than hot rolling. Seamless is a  10.20.30.35.45  other high quality carbon steel  16Mn.5MnV  low-alloy structural steel or 40Cr.30CrMnSi.45Mn2.40MnB  like structural steel or cold rolled steel. Seamless pipes made of mild steel such as 10.20  are mainly used for fluid transportation pipelines. 45.40Cr  seamless tube made of steel or the like used to make mechanical parts, such as automobiles . Tractor force components. Generally, seamless steel pipes must be used for strength and flattening tests. Hot-rolled steel pipes are delivered in hot-rolled state or heat-treated state; cold-rolled steel pipes are delivered in hot-heated state.


   Definition and classification of two steel pipes (two)


  Low-pressure boiler seamless steel pipe: for the manufacture of a variety of low pressure boiler . Superheated steam pipes . Boiling water pipe . Waterwall tubes and superheated steam locomotive boiler tubes . Opium pipe . Small pipe and brick arch tubes. Use high-quality carbon structural steel hot-rolled or cold-rolled (dial) seamless steel pipe. Mainly with  10.20  Number steel, in addition to ensure the chemical composition and mechanical properties of pressure to do testing, crimping . Flaring . Flattening tests. Hot-rolled products are delivered in the hot-rolled state . Cold-rolled products are delivered in the heat-treated state.


  High pressure boiler steel: mainly used to manufacture a high-carbon steel and high-pressure steam boiler pipe pressure above the like . Alloy steel and heat-resistant stainless steel seamless pipe . Boiler tubes by the party in work at high temperatures and pressures . tubes also under the action of high temperature flue gas and steam oxidation and corrosion, thus requiring durable steel with high strength . high oxidation resistance, and good structural stability, use of steel are: high quality carbon Structural steel grades are  20G. , 20MnG. , 25MnG ;


  Alloy structural steel: 15MoG. , 20MoG. , 12CrMoG. , 15CrMoG , 12Cr2MoG , 12CrMoVG. , 12Cr3MoVSiTiB, etc.;


  Rust resistant steel used: 1Cr18Ni9 , 1Cr18Ni11Nb high pressure boiler tubes in addition to chemical composition and mechanical properties, hydrostatic testing done by the root, to be flaring . Flattening test. The steel pipe is delivered in a heat-treated state. In addition, the finished steel microstructure . Grain size . Decarburized layer may have certain requirements. Drilling rigs and petroleum geological drilling seamless steel pipe; In order to investigate the structure of subterranean formations . Groundwater . Oil . Gas and mineral resources, the use of drilling rigs. Oil . Gas extraction can not do without drilling, geological drilling control with


  Oil drilling seamless main drilling equipment, including the outer core barrel . Inner core barrel . Casing . Drill pipe. Since the drilling tube to be several kilometers deep into the ground the working depth, the working condition is very complex, subjected to tensile rod . Compression . Bent . Stress and unbalanced torsional impact load, etc., but also by the mud . Rocks wear, therefore, required pipe must have sufficient strength . hardness . wear resistance and impact toughness, with the pipe steel " the DZ " (geology Pinyin prefix) plus the number represented by a representative of the yield point steels, the steel used has  DZ45  of 45MnB.50Mn ; DZ50  of  40Mn2.40Mn2Si ; DZ55  of  40Mn2Mo.40MnVB ; the DZ60 of 40MnMoB.DZ65  of  27MnMoVB . The steel pipes are delivered in a heat-treated state.


  Petroleum cracking tubes: the tubes used in the oil refinery . Heat exchanger tubes and seamless pipes. Commonly used high-quality carbon steel ( 10.20 ) . Alloy steel ( 12CrMo.15CrMo ) . Heat-resistant steel ( 12Cr2Mo.15Cr5Mo ) . Stainless steel ( 1Cr18Ni9.1Cr18Ni9Ti ). Steel chemical composition and permit the divided various mechanical properties, but also to ensure that the water pressure . Flattening . Flaring test, etc., and non-destructive testing and surface quality. The steel pipe is delivered under heat treatment.


  Stainless steel tube: stainless steel with a variety of hot-rolled, cold-rolled stainless steel pipes, are widely used in petroleum . Stainless steel piping and chemical equipment parts for various purposes, in addition to the chemical composition should ensure mechanical properties and, where exposed to fluid pressure as steel To ensure that the water pressure test is qualified. All kinds of special steel pipes must be guaranteed according to the stipulated conditions. Welded steel pipe: also called welded pipe, it is made of steel plate or steel strip after bending and forming, and then welding. According to the weld form, it is divided into straight seam welded pipe and spiral welded pipe. Usually pipe is divided according to use . Galvanized pipe . Oxygen pipe . Wire casing . Metric pipe . Idler tube . Deep well pipe . Automobile tubes . Transformer tube . Welded thin-walled tube . Welded pipe and spiral shaped tubes. General welded pipe: General welded pipe is used to transport low-pressure fluid. Use  Q195A.Q215A.Q235A


  Made of steel. It can also be made of other mild steel that is easy to weld. To steel pressure . Bending . Flattening and other experiments, there are certain requirements for the surface quality, usually delivery length of  4-10m , often require Length (or double length) delivery. The specifications of welded pipes are expressed by the nominal diameter (mm or inches). The nominal diameter is different from the actual. Welded pipes are divided into two types: ordinary steel pipes and thickened steel pipes according to the specified wall thickness. The steel pipes are divided into threaded and non-threaded types according to the tube end form.


   Definition and classification of three steel pipes (three)


  Galvanized steel pipe: In order to improve the corrosion resistance of the steel pipe, the general steel pipe (black pipe) is galvanized. Galvanized steel pipes are divided into two types: hot-dip galvanizing and electric steel zinc. The hot-dip galvanizing layer is thick and the cost of electro-galvanizing is low.


  Oxygen-blowing welded pipe: Used as a steel-making oxygen-blowing pipe, generally small-diameter welded steel pipes, with eight specifications  ranging from 3/8  inch to 2  inch. It is made of 08.10.15.20 or  Q195-Q235  steel strip. In order to prevent corrosion, some are aluminized.


  Wire casing: It is also an ordinary carbon steel electric welded steel pipe, used in concrete and various structural power distribution projects. The commonly used nominal diameter is from 13-76mm . The wall of the wire sleeve is thin, and most of it is used after coating or galvanizing, and a cold bending test is required.


  Metric pipe: seamless form with specifications, outer diameter * welded pipe wall thickness in millimeters, with ordinary carbon steel . High carbon steel or low alloy steel P to tropical . With cold welding, or welding after tropical Then it is made by cold dialing method. Metric pipe P to points and a thin . Common as a structural member, such as a propeller shaft, or transmission fluid, for the production of thin-walled furniture . Lamps, etc., to ensure that the steel pipe and bending strength test.


  Roller tube:  Electric welded steel pipe used for the roller of belt conveyor, generally made of Q215.Q235A.B  steel and  20  steel, with a diameter of 63.5-219.0mm . There are certain requirements for the bending degree of the tube . The end face should be perpendicular to the center line . The ovality has certain requirements, and the water pressure and flattening tests are generally carried out.


  Transformer tube: for the manufacture of transformers and other heat pipe heat exchanger, using ordinary carbon steel, flattening required . Flared . Bend . Hydraulic pressure test. Steel pipes are delivered in fixed-length or double-length, and there are certain requirements for the bending of the steel pipe.


  Pipes: carbon structure by the ordinary structural steel and 16Mn  square tube made of welded steel . Rectangular tube . Cap tube . Empty plastic steel doors


  Steel pipes are mainly used for agricultural machinery parts . Steel windows and doors, etc. Welding thin-walled tube: mainly used to make furniture . Toys . Lamps. In recent years, thin-walled tube made of stainless steel with a very extensive, high-quality furniture . Decoration . Fences and so on.


  Spiral welded pipe: It is the low-carbon carbon structural steel or low-alloy structural steel strip according to a certain spiral angle (called forming


  The angle) is rolled into a tube blank, and then the tube seam is welded together. It can use a narrower strip to produce a large diameter steel tube. Spiral pipe mainly used in oil . Gas delivery line, the outer diameter size which * denotes the wall thickness. Spiral welded pipes can be welded on one side or on both sides. Welded pipes should be tested under hydrostatic pressure . The tensile strength and cold bending performance of the weld must meet the requirements.



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