Double-layer Welded Steel Pipes Producing
Welded steel pipes are made by rolling a strip of steel and then welding the two edges along the seam. The welded steel pipe has many advantages, such as high strength, good rigidity, and low cost. As the demand for steel pipes increases, the technology of welding steel pipes is important.
In the production of double-layer welded steel pipes, the copper-coated steel strip consisting of two layers of steel and one layer of copper is used as raw material. Steel strips of different thicknesses are rolled and formed into a cylindrical shape with an outer layer and an inner layer. The use of copper-coated steel strips requires orbital welding. The advantage of using double-layer welding steel pipe is that it can prevent galvanic corrosion that occurs in the circumferential direction.
The outer layer of the double-layer welded steel pipes can be made of low carbon steel, such as Q215B and Q235B. High strength steel, such as Q345B, can also be used for the outer layer. The inner layer is usually made of black steel, Q235 or Q345. It can also be made of stainless steel or other materials. The thickness of the steel strip determines the size of the double-layer welded steel pipe.
During the process of double-layer welded steel pipe producing, the formation process is mainly divided into three parts. The first part is pre-forming to shape the pipe and control its size; the second part is welding technology to ensure the quality of the welded seam; the third part is final forming to ensure the correct shape and size.
In pre-forming, the steel strip is centred on the machine and rolled into a cylindrical shape. The advantage of using pre-forming is that the size of the pipe can be controlled more accurately. After pre-forming, the welding process is started. The pipe with the dual layer is then welded together. The orbital welding technology is used for the welding process. This process is suitable for feeding and turning welds, and is less destructive to pipe walls. This ensures the stability of the welded seam, the stability of the welded pipe, and the even and consistent welding status.
After welding, the double-layer welded steel pipe needs to be cooled and solidified. Finally, the forming process is implemented. During this process, the method of rolling or bending can be used to adjust the shape and size of the pipe. After forming is completed, the length, diameter and wall thickness of the double-layer welded steel pipe is tested. If the size is qualified, the steel pipe can be put into use.
Double-layer welded steel pipe has a wide range of applications in the chemical, petroleum, power engineering, water supply and drainage and construction industry due to its light weight, high strength and corrosion resistance. The production of double-layer welded steel pipes requires high quality raw material, advanced technology and precise production process. Therefore, a qualified manufacturer should is required to guarantee quality.
