Welded steel pipe: also called welded pipe, which is formed by bending a steel plate or a steel strip and then welded. According to the form of weld, it is divided into
lsaw steel pipe and
ssaw steel pipe. It is divided into general welded pipe, galvanized welded pipe, blown oxygen welded pipe, wire casing, metric welded pipe, idler pipe, deep well pump pipe, automobile pipe and transformer pipe according to the application. , welded thin-walled tubes, welded shaped tubes and spiral welded tubes.
General welded pipe: Generally welded pipe is used to transport low pressure fluid. Made of Q195A, Q215A, Q235A steel. It can also be made of other mild steel that is easy to weld. The steel pipe is subjected to experiments such as water pressure, bending and flattening, and has certain requirements on the surface quality. Usually, the delivery length is 4-10 m, and the fixed length (or double rule) is often required for delivery. The specification of the welded pipe is expressed by the nominal diameter (mm or inch). The nominal diameter of the welded pipe is different from the actual one. The welded pipe has two kinds of ordinary steel pipe and thick steel pipe according to the specified wall thickness. The steel pipe is divided into two types according to the pipe end and the thread is not threaded.
With the improvement of welded steel pipe technology and the ease of processing, now welded pipes replace some
seamless steel pipes, and welded steel pipes can produce more than 219mm (8 inches). Galvanized steel pipes: In order to improve the corrosion resistance of steel pipes, general steel pipes (black pipes) are galvanized. Galvanized steel pipes are divided into hot-dip galvanizing and electric steel zinc. The hot-dip galvanizing galvanized layer is thick and the cost of electro-galvanizing is low. Blowing oxygen welded pipe: used as a steel pipe for oxygen blowing, generally with small diameter welded steel pipe, the specifications are from 8/8 inch to 2 inch. Made of 08, 10, 15, 20 or Q195-Q235 steel strip. For corrosion protection, some are aluminized.
Wire bushing: 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 sleeve of the wire sleeve is thin, and most of it is coated or galvanized, and a cold bend test is required. Metric welded pipe: The specification is in the form of a seamless pipe. The welded steel pipe is expressed by the outer diameter multiplied by the wall thickness mm. It is welded with tropical carbon steel, high quality carbon steel or plain low alloy steel, or welded with a tropical belt. It is then made by cold dialing.
Metric welded pipes are divided into general and thin walls, which are commonly used as structural members, such as transmission shafts, or for conveying fluids. Thin walls are used to produce furniture, lamps, etc., to ensure the strength and bending test of steel pipes. Roller tube: used for belt conveyor electric welding steel pipe, generally made of Q215, Q235A, B steel and 20 steel, diameter 63.5-219.0mm. The pipe bending degree, the end surface should be perpendicular to the center line, and the ellipticity is required. Generally, the water pressure and the flattening test are performed.
Transformer tube: used to manufacture transformer heat pipe and other heat exchangers. It is made of ordinary carbon steel and requires flattening, flare, bending and hydraulic testing. Steel pipes are delivered in fixed lengths or multiples, which have certain requirements for the bending of steel pipes. Shaped tube: square tube, rectangular tube, hat tube, empty steel door and window steel tube welded by ordinary carbon knot structural steel and 16Mn steel, mainly used as agricultural machinery components, steel window doors, etc.
Electric welding thin wall tube: mainly used to make furniture, toys, lamps and so on. In recent years, thin-walled tubes made of stainless steel strips have been widely used, such as high-grade furniture, decoration, and fences. Spiral welded pipe: It is made by rolling a low carbon carbon structural steel or a low alloy structural steel strip into a tube blank at a certain angle of a helix (called a forming angle), and then welding the pipe joint to make it narrower. Strip steel produces large diameter steel pipes. Spiral welded pipe is mainly used for oil and natural gas transmission pipelines, and its specifications are expressed by outer diameter * wall thickness. Spiral welded pipes are single-sided welded and double-sided welded. The welded pipe shall ensure that the hydraulic test and the tensile strength and cold bending performance of the weld are in compliance with the regulations.
