Welded Steel Pipe Manufacturer

Welded Pipe Categories: General Welded Pipe, Seamless Welded Pipe, Spiral Welded Pipe

Welded steel pipes refer to pipes that are formed by bending and deforming steel strips or plates into shapes such as circular or square, and then welded together, featuring a seam on the surface. The billets used for welding steel pipes are steel plates or strips.

General Welded Pipe

General welding pipes are used for conveying low-pressure fluids. They are manufactured from steel grades such as Q195A, Q215A, and Q235A. Other easily weldable soft steels can also be used. The pipes must undergo hydrostatic, bending, and flattening tests, with certain surface quality requirements. The standard delivery length is typically 4-10 meters, often requiring fixed-length (or multiple of fixed length) delivery. The specifications of welding pipes are indicated by nominal diameter (in millimeters or inches), which may differ from the actual diameter. Welding pipes are available in two types: standard wall thickness and reinforced wall thickness, and they are also categorized as threaded or unthreaded based on the end form.

Seamless Welded Pipe

Process is simple, efficiency high, cost low, and development rapid.

Specification: Φ21.3-457.2*1.8-14

Spiral Welded Pipe

Strength is generally higher than that of straight seam welded pipes, allowing for larger diameter pipes to be produced from narrower billets, and also for pipes of different diameters to be produced from the same width billets. However, compared to straight seam pipes of the same length, the weld length increases by 30~100%, and the production speed is slower. Therefore, smaller diameter welded pipes are mostly produced using straight seam welding, while larger diameter pipes are predominantly produced using spiral welding.

Spiral-welded steel pipes are divided into two types: automatic submerged arc welding pipes and high-frequency welding pipes.

Spiral seam automatic submerged arc welded steel pipes are divided into two categories: Class A pipes and Class B pipes, based on the pressure levels of the transported medium. Class A pipes are generally made of ordinary carbon structural steel Q235, Q235F, and low-alloy structural steel 16Mn for welding, while Class B pipes are made of steel materials such as Q235, Q235F, and Q195 for welding, used as low-pressure fluid transmission pipes.

b. Spiral Seam High-Frequency Welded Steel Pipe - There is no unified product standard for spiral seam high-frequency welded steel pipes. They are generally manufactured using common carbon steel grades such as Q235, Q235F, and others.

Specification: Φ219-2320*6-22

Standard

GB/T3091-1993 (Galvanized Welded Steel Pipe for Low-Pressure Fluid Transportation). Primarily used for conveying water, coal gas, air, oil, heating hot water, or steam, among other low-pressure fluids and for various other piping applications. The representative material is Q235A steel.

GB/T3092-1993 (Galvanized Welded Steel Pipe for Low Pressure Fluid Transportation). Primarily used for transporting water, gas, air, oil, and heating hot water or steam, as well as other general low-pressure fluids and pipe applications. The representative material is Q235A steel.

GB/T14291-1992 (Fluid Conveyance Welded Steel Pipes for Mining). Primarily used for straight seam welded steel pipes in mining for pressure ventilation, drainage, and shaft gas venting. The representative materials are Q235A and B-grade steel. GB/T14980-1994 (Large Diameter Electric Welded Steel Pipes for Low-Pressure Fluid Conveyance). Mainly used for conveying low-pressure fluids such as water, wastewater, coal gas, air, heating steam, and other applications. The representative material is Q235A-grade steel.

GB/T12770-1991 (Welded Steel Pipes for Mechanical Structures). Primarily used in machinery, automobiles, bicycles, furniture, hotel and restaurant decoration, and other mechanical components and structural parts. Representative materials include 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, and so on.

GB/T12771-1991 (Welded Steel Pipe for Fluid Transmission). Primarily used for transporting low-pressure corrosive media. Representative materials include 0Cr13, 0Cr19Ni9, 00Cr19Ni11, 00Cr17, 0Cr18Ni11Nb, and 0017Cr17Ni14Mo2.