Welded steel pipe refers to steel pipe deformed with steel strip or steel plate
August 02, 2022
Welded steel pipe refers to steel pipe or steel plate bent into a round, square and other shapes and then welded into the surface of the steel pipe with seams. Welded steel pipe blanks are steel or strip steel.
Classification of welding methods According to different welding methods can be divided into arc welded pipe, high frequency or low frequency resistance welded pipe, gas welded pipe, furnace pipe, Bondi tube and so on.
Welded steel pipe: used for oil drilling and machinery manufacturing.
Furnace welded pipe: used as water gas pipe, large-diameter straight seam welded pipe for high pressure oil and gas transmission, spiral welded pipe for oil and gas transmission, pipe piles, bridge piers, etc.
Welded steel pipe can be divided into straight seam welded pipe and spiral welded straight seam welded pipe according to the shape of the weld seam: the production process is simple, the production efficiency is high, the cost is low, and the development is rapid.
Spiral welded pipe: The strength is generally higher than that of a straight seam welded pipe. A narrower blank can be used to produce a larger diameter pipe. It is also possible to use a blank of the same width to produce a different diameter pipe. However, compared with the straight seam pipe of the same length, the length of the weld seam increases by 30 to 100%, and the production speed is low. Therefore, the smaller diameter welded pipe mostly adopts the straight seam welding, and the large diameter welded pipe adopts the spiral welding.
Spiral seam welded steel pipe is divided into automatic submerged arc welded steel pipe and high frequency welded steel pipe.
a. Spiral seam automatic submerged arc welded steel pipes are classified into two types: Class A pipe and Class B pipe according to the pressure of the medium. Class A pipe is generally welded with common carbon steel Q235, Q235F and general low alloy structural steel 16Mn, and class B pipe is welded with steel Q235, Q235F, Q195, etc., used as low pressure fluid conveying pipe
b. Spiral seam high-frequency welded steel pipe spiral seam high-frequency welded steel pipe, there is no uniform product standard, generally made of ordinary carbon steel Q235, Q235F and other steel manufacturing.
Welded steel pipes are divided into general welded pipes, galvanized welded pipes, blown oxygen welded pipes, wire bushings, metric welded pipes, idler pipes, deep well pump pipes, automotive pipes, transformer pipes, welded thin-walled pipes, and electric welding profiles. Pipe and spiral welded pipe.
General welded pipe: The general welded pipe is used to deliver low pressure fluid. Made of Q195A, Q215A, Q235A steel. It can also be made of other mild steels that are easy to weld. The steel pipe should be subjected to hydraulic pressure, bending, flattening and other tests. It has certain requirements on the surface quality, usually the delivery length is 4-10m, and often requires length (or multiple feet) delivery. The specification of the welded pipe is expressed by the nominal diameter (mm or inches). The nominal diameter is different from the actual one. The welded pipe has two kinds of ordinary steel pipe and thicker steel pipe according to the specified wall thickness. The steel pipe is divided into two types according to the pipe end.
Galvanized steel pipe: In order to improve the corrosion resistance of the steel pipe, the general steel pipe (black pipe) is galvanized. Galvanized steel is divided into hot dip galvanized steel and electric steel zinc. The hot dip galvanized galvanized layer is thick and the cost of electrogalvanizing is low.
Blown Oxygen Pipe: Used as oxygen-blowing steel pipe for steelmaking. It is generally made of small-diameter welded steel pipe, and its specifications range from 3/8 inch to 2 inch. Made with 08, 10, 15, 20 or Q195-Q235 steel strips. In order to prevent corrosion, some aluminizing treatment.
Wire Jacket: Also common carbon steel welded steel pipe, used in concrete and various structural distribution engineering, commonly used nominal diameter from 13-76mm. The casing wall of the wire bushing is relatively thin, and most of them are used after coating or galvanizing. The cold bending test is required.
Metric welded pipe: The specification is in the form of a seamless pipe. Welded steel pipe expressed in outside diameter*thickness mm is welded with ordinary carbon steel, high-quality carbon steel or Pu-nor low-alloy steel in tropical or cold zone, or after welding in the tropics. Then made by cold dial method. The metric welded pipe can be divided into general-purpose and thin-walled, commonly used as structural parts, such as transmission shafts, or conveying fluids, thin-walled to produce furniture, lamps, etc., to ensure strength and bending test of the steel pipe.
Roller tube: It is used for the welding roller of belt conveyor roller. It is usually made of Q215, Q235A, B steel and 20 steel with a diameter of 63.5-219.0mm. The tube bending, the end face should be perpendicular to the centerline, and the ellipticity must have certain requirements. Generally, water pressure and flattening tests are performed.
Transformer tube: It is used to make transformer heat pipe and other heat exchangers. It is made of common carbon steel and requires flattening, flaring, bending and hydraulic tests. The delivery of steel pipes by a fixed length or multiple feet has certain requirements for the bending of the steel pipes.
Shaped tubes: square tube, rectangular tube, hat-shaped tube, and steel pipe for windows, windows, and doors made of ordinary carbon-junction structural steel and 16Mn steel, mainly used as agricultural machinery components, steel window doors, etc.
Welded thin-walled pipe: mainly used to make furniture, toys, lamps and so on. The current thin-walled tube made of stainless steel is widely used in advanced furniture, decoration, fences and so on.
Spiral Welded Pipe: It is made by winding a low carbon carbon structural steel or low alloy structural steel strip into a blank according to a certain helix angle (called forming angle), and then welding it together. It can be used in a narrower way. Strip production of large diameter steel pipes. Spiral welded pipes are mainly used for oil and natural gas transmission pipelines, and their specifications are expressed in terms of outer diameter* wall thickness. Spiral welded pipe with single-sided welding and double-sided welding, welded pipe should ensure that the hydrostatic test, weld tensile strength and cold bending performance to meet the requirements.
Welded steel pipe according to the shape of the end classification is divided into round welded pipe and special-shaped (square, flat, etc.) welded pipe.
The classification is different and is divided into:
GB/T3091-1993 (galvanized welded steel pipe for low pressure fluid delivery). Mainly used to transport water, gas, air, oil and heating water or steam and other general low pressure fluid and other uses. It stands for Q235A grade steel.
GB/T3092-1993 (Galvanized Welded Steel Pipe for Low Pressure Fluid Transport). Mainly used to transport water, gas, air, oil and heating water or steam and other general low pressure fluids and other uses. Its representative material is: Q235A grade steel.
GB/T14291-1992 (mine fluid transport welded steel pipe). It is mainly used in mine pressure air, drainage, axial gas pipelines and straight seam welded steel pipes. Its representative material Q235A, B grade steel. GB/T14980-1994 (large diameter welded steel pipe for low pressure fluid delivery). Mainly used for conveying water, sewage, gas, air, heating steam and other low-pressure fluids and other uses. It stands for Q235A grade steel.
GB/T12770-1991 (stainless steel welded pipe for mechanical structures). Mainly used for machinery, automobiles, bicycles, furniture, hotel and restaurant decoration and other mechanical parts and structural parts. Its representative material 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb and so on.
GB/T12771-1991 (stainless steel welded pipe for fluid transport). It is mainly used for conveying low-pressure corrosive media. Representative materials are 0Cr13, 0Cr19Ni9, 00Cr19Ni11, 00Cr17, 0Cr18Ni11Nb, 0017Cr17Ni14Mo2 and so on.
This information source:.
Shandong Rizhaoxin Metal Products Co., Ltd.
