Classification of welding methods for large diameter steel pipes

Classification of welding methods for large diameter steel pipes
According to different welding methods, it can be divided into arc welding pipe, high frequency or low frequency resistance welding pipe, gas welding pipe, furnace welding pipe, Bondi pipe and so on.
Electric welded steel pipe: used in oil drilling and machinery manufacturing.
Furnace welded pipe: can be used as water gas pipe, etc., large mouth straight seam welded pipe for high pressure oil and gas transmission; Spiral welded pipe is used for oil and gas conveying, pipe pile, bridge pier, etc.
Classification by weld shape
Can be divided into straight seam welded pipe and spiral welded pipe
Straight seam welded pipe
The production process is simple, the production efficiency is high, the cost is low, the development is fast.
Spiral welded pipe
The strength is generally higher than that of straight welded pipe, and welded pipes with larger diameters can be produced with narrower billets, and welded pipes with different diameters can also be produced with billets of the same width. However, compared with the straight seam pipe of the same length, the weld length is increased by 30 to 100%, and the production speed is lower. Therefore, the smaller diameter welded pipe is mostly straight seam welding, and the large diameter welded pipe is mostly spiral welding.
Spiral welded steel pipes are divided into automatic submerged arc welded steel pipes and high-frequency welded steel pipes.
a, spiral seam automatic submerged arc welded steel pipe according to the pressure of the conveying medium is divided into two categories: A tube and B tube. Class A pipes are generally welded with ordinary carbon steel Q235, Q235F and ordinary low-alloy structural steel 16Mn, and Class B pipes are welded with Q235, Q235F, Q195 and other steels, which are used as low-pressure fluid conveying pipes
b, spiral seam high-frequency welded steel pipe Spiral seam high-frequency welded steel pipe, there is no unified product standard, generally using ordinary carbon steel Q235, Q235F and other steel manufacturing.
Classification by use
According to the use, it is divided into general welded pipe, galvanized welded pipe, blown oxygen welded pipe, wire casing, metric welded pipe, roller pipe, deep well pump pipe, automobile pipe, transformer pipe, electric welded thin-wall pipe, electric welded special shape pipe and spiral welded pipe.
Ordinary welded pipe
General welding pipe to transport low pressure fluid. Made of Q195A, Q215A, Q235A steel. It can also be made of other soft steels that are easy to weld. Steel pipe to carry out water pressure, bending, flattening and other experiments, there are certain requirements on the surface quality, usually the delivery length is 4-10m, often require fixed size (or double size) delivery. The specification of the welded pipe is expressed by the nominal diameter (mm or inch). The nominal diameter is different from the actual one. The welded pipe has two kinds of ordinary steel pipe and thickened steel pipe according to the specified wall thickness, and the steel pipe is divided into two kinds with thread and without thread according to the form of 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 pipe is divided into hot dip galvanized and electric galvanized two, hot dip galvanized galvanized layer is thick, electric galvanized low cost.
Oxygen blow welding pipe
Used as steel blowing oxygen pipe, generally with small diameter welded steel pipe, specifications from 3/8 inch to 2 inch eight. Made of 08, 10, 15, 20 or Q195-Q235 steel strip. In order to prevent corrosion, some are aluminized.
Wire bushing
It is an ordinary carbon steel welded steel pipe, used in concrete and various structural power distribution projects, and the commonly used nominal diameter is from 13-76mm. The wall of the wire jacket is thin, and most of them are used after coating or galvanized, requiring cold bending test
Metric welded pipe
Specifications Welded steel pipe in the form of seamless pipe, with outer diameter * wall thickness mm, with ordinary carbon steel, high-quality carbon steel or general energy low alloy steel tropical, cold zone welding, or tropical welding and then made by cold drawing method. The metric welded pipe can be used as a structural part, such as a drive shaft, or to transport fluids, and the thin wall is used to produce furniture, lamps, etc., to ensure the strength and bending test of the steel pipe.
Idler tube
Used for belt conveyor roller electric welding steel pipe, generally made of Q215, Q235A, B steel and 20 steel, diameter of 63.5-219.0mm. There are certain requirements for tube bending, end face perpendicular to the center line and ellipticity, and water pressure and flattening tests are generally carried out.
Transformer tube
For the manufacture of transformer heat pipe and other heat exchangers, the use of ordinary carbon steel manufacturing, requiring flattening, flaring, bending, hydraulic tests. The steel pipe is delivered in fixed size or double size, and the bending degree of the steel pipe has certain requirements.
Special pipe
Square pipe, rectangular pipe, cap pipe, empty rubber steel door and window steel pipe welded by ordinary carbon structure steel and 16Mn steel strip, mainly used for agricultural machinery components, steel window doors and so on.
Electric welded thin-walled tube
Mainly used to make furniture, toys, lamps and so on. At present, the thin wall pipe made of stainless steel belt is widely used in high-end furniture, decoration, fence and so on.
Spiral welded pipe
Is the low carbon carbon structural steel or low alloy structural steel strip according to a certain helix Angle (called forming Angle) rolled into a tube blank, and then welded the pipe seam made, it can use a narrow strip steel to produce large diameter steel pipe. Spiral welded pipe is mainly used for oil and natural gas transmission pipelines, and its specifications are expressed by outer diameter * wall thickness. The spiral welded pipe has one side welding and two side welding, and the welded pipe should ensure that the water pressure test, the tensile strength of the weld and the cold bending performance should meet the requirements.
Sort by end shape
It is also divided into round welded pipes and special-shaped (square, flat, etc.) welded pipes.