Welded steel pipes can be classified into different types and types according to different classification methods. Welded steel pipes of different properties have different characteristics and characteristics in use and show different use values in use. Welded steel pipes can be classified into the following categories according to their uses: generally welded steel pipes, galvanized welded steel pipes, oxygen-blown welded steel pipes, wire casings, metric welded steel pipes, roller pipes, deep well pump pipes, automotive pipes, transformer pipes, electric welding Thin-walled pipes, electric welded special-shaped pipes and spiral welded steel pipes. Different welded steel pipes show different use values and functions in use, and the production process will be different. The national production standards that need to be followed are also different. The following briefly introduces the characteristics and advantages of welded steel pipes of different types and properties:
General welded steel pipe: General welded steel pipe is used to transport low-pressure fluid. Made of Q195A, Q215A, Q235A steel. Also available in other mild steels that are easy to weld. The steel pipe needs to be tested for water pressure, bending, flattening, etc., and has certain requirements on the surface quality. Usually, the delivery length is 4-10m, and it is often required to deliver to a fixed length (or multiple feet). The specification of the welded steel pipe is expressed by the nominal diameter (mm or inch). The nominal diameter is different from the actual one. The welded steel pipe is divided into two types: ordinary steel pipe and thickened steel pipe according to the delineated wall thickness. kind.
Transformer tube: used to manufacture transformer radiator tubes and other heat exchangers, made of ordinary carbon steel, and required to be flattened, flared, bent, and hydraulically tested. The steel pipe is delivered in fixed length or double length, and there are certain requirements for the bending degree of the steel pipe.
Special-shaped pipe: square pipe, rectangular pipe, hat-shaped pipe, hollow rubber steel door and window steel pipe welded by ordinary carbon structural steel and 16Mn steel strip, mainly used for agricultural machinery parts, steel windows and doors, etc.
Galvanized steel pipe: To improve the corrosion resistance of steel pipe, the general steel pipe (black pipe) is galvanized. Galvanized steel pipe is 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.
Roller tube: It is used for electric welded steel pipe of belt conveyor idler, generally made of Q215, Q235A, B steel, and 20 steel, with a diameter of 63.5-219.0mm. There are certain requirements for the curvature of the tube, the end face should be perpendicular to the center line, and the ovality. Generally, water pressure and flattening tests are carried out.
Oxygen-blown welded steel pipe: used for steel-making oxygen-blown pipes, generally small-diameter welded steel pipes, with eight specifications ranging from 3/8 inches to 2 inches. Made with 08, 10, 15, 20, or Q195-Q235 steel strips. To prevent corrosion, some are aluminized.
Welded thin-walled tubes: mainly used to make furniture, toys, lamps, etc. In recent years, thin-walled tubes made of stainless steel strips have been widely used in high-end furniture, decoration, and fences.
Wire casing: It is also an ordinary carbon steel electric welded steel pipe, which is used in concrete and various structural power distribution projects. The commonly used nominal diameter is 13-76mm. The wall of the wire sleeve is relatively thin, and most of them are used after coating or galvanizing, and a cold bending test is required.
Metric welded steel pipe: the specification is in the form of a seamless pipe, and the welded steel pipe is expressed in millimeters of outer diameter * wall thickness, welded with the hot and cold strips of ordinary carbon steel, high-quality carbon steel or general low-alloy steel, or welded with hot strips Then it is made by the cold-dial method. Metric welded steel pipes are divided into general and thin-walled and are generally used as structural parts, such as drive shafts, or to transport fluids. Thin-walled steel pipes are used to produce furniture, lamps, etc., to ensure the strength and bending test of the steel pipe.
Spiral welded steel pipe: It is made by rolling low carbon structural steel or low alloy structural steel strips at a certain helix angle (called forming angle) into a tube blank and then welding the pipe seams. The strip steel produces large-diameter steel pipes. Spiral welded steel pipes are mainly used for oil and natural gas transmission pipelines, and their specifications are expressed by outer diameter * wall thickness. Spiral welded steel pipe has single-sided welding and double-sided welding.
Different types and functions of welded steel pipes are used in different ranges and environments, and the methods of use in production and processing are also different. Therefore, when using welded steel pipes, should be used according to different situations to ensure the value of welded steel pipes in use.