The straight seam steel pipe refers to the steel pipe parallel to the length direction of the weld and the steel pipe. It is usually made of steel belt or steel plate through straight seam high -frequency melting equipment. Depending on the production process and use of straight steel pipes, straight steel pipes can be divided into various types, such as public electric welding steel pipes, welding thin wall pipes, transformer cooling oil pipes, etc. In addition, according to the subsequent production process and use, it can be subdivided into scaffolding tubes, fluid pipes, wire sleeves, support pipes and fence pipes.
1. Detective: After the steel plate used to make large -caliber buried arc welding straight seam steel pipes enters the production line, the full board ultrasonic inspection is performed first.
2. Mill edge: Double -sided milling on the two edges of the steel plate is used to achieve the requirements of the plate width, parallel parallel to the parallel side of the plate, and the shape of the slope.
3. Pre -bending edge: Use the pre -bending machine to carry the pre -bending of the board to make the edge of the board have a curved curvature.
4. For molding: First, the pre-curved steel plate was first stamped on the JCO molding machine, pressed multiple steps after multiple steps, pressed it into a J-shaped, and then the other half of the steel plate was also bent to C-shaped, and finally formed an O-shaped O-shaped O-shaan Essence
5. Pre -welding: Make the forming straight welding steel pipes sew and use gas protection welding (MAG) for continuous welding.
6. Internal welding: Welded with a columns of wire buried arc welding (up to four wires) on the inside of the straight steel pipe.
7. External welding: Welded on the outside of the stitched arc welded steel pipe with a splitted curved arc.
8. Ultrasonic inspection I: 100%inspection of the welded seams and welds on the inside and outside of the straight welded steel pipes.
9. X -ray inspection I: 100%X -ray industrial TV inspection of welds in internal and external welds, using an image processing system to ensure the sensitivity of the detection.
10. Expansion: The full length of the buried arc welding straight seam steel pipe is expanded to improve the size and accuracy of the steel pipe and improve the distribution state of the stress in the steel pipe.
11. Hydraulic test: The steel pipe after the diameter expanded on the hydraulic test machine is inspected to ensure the test pressure of the steel pipe to meet the standard requirements. The machine has an automatic recording and storage function.
12. Inverted edge: The tube ending the tube after the inspection is passed to achieve the size of the tube end slopes.
13. Ultrasonic test II: The ultrasonic inspection is performed again to check the defects that the straight welded steel pipes may produce after the diameter and water pressure.
14. X -ray examination II: The X -ray industrial TV inspection and pipe welds were performed on the steel pipes after the diameter and hydraulic test.
15. Tube -side magnetic powder test: This inspection is performed to discover the tube -side defects.
16. Anti -corrosion and coating: The qualified steel pipes perform anticorrosion and coating according to user requirements.
