Welded steel pipe is a steel pipe in which the edges of steel plates or strip coils are welded into a cylindrical shape. According to the welding method and shape, welded steel pipes can be divided into the following categories:

Longitudinal welded steel pipe (LSAW/ERW): Longitudinal welded steel pipe is a steel pipe in which the edges of steel plates or strip coils are butted and then welded in a straight line. This kind of steel pipe has good strength and low production cost, but its strength is slightly lower than that of the spiral welded steel pipe of the same specification.

Spiral Welded Steel Pipe (SSAW): Spiral welded steel pipe is a steel pipe in which strip steel is rolled into a cylinder and welded in a helical direction. This kind of steel pipe has higher strength, but the production cost is slightly higher.

The main uses of welded steel pipes are as follows:

Conveying pipelines: Welded steel pipes are widely used to transport oil, natural gas, gas, water and other fluids, especially in urban gas and water supply systems.

Structural pipe: Welded steel pipes are used in engineering fields such as building structures, bridges, steel frames, and supports. They have good bearing capacity and shock resistance.
Machinery manufacturing: Welded steel pipes can be used to manufacture various mechanical parts, such as shafts, brackets, conveyor rollers, etc.

Oil and gas drilling: Welded steel pipes can be used in the manufacture of oil and gas drilling and oil production equipment, such as drill pipes, casings, etc.
Tower Fabrication: Welded steel pipes are used in the fabrication of broadcasting and communication towers.

Greenhouses: Welded steel pipes are often used in the manufacture of supports for greenhouses due to their lower cost and better strength.
Bicycle and motorcycle manufacturing: Welded steel pipes are used to make the frames of bicycles and motorcycles.

Furniture manufacturing: Welded steel pipes can be used to produce various furniture such as bed frames, bookshelves, chairs, etc.

In short, welded steel pipes have a wide range of applications, and their uses depend on the type, specification and material of the steel pipe. When selecting welded steel pipes, the appropriate steel pipe type should be determined according to actual needs and engineering environment. At the same time, the installation, use and maintenance of steel pipes are also key factors affecting their performance and service life, and relevant specifications and standards need to be strictly followed.