LSAW Steel Pipe (Longitudinal Submerged Arc Welding)

The LSAW steel pipe is made from individual medium thickness steel plates. The steel plate is pressed or rolled into a billet in a mold or forming machine. The billet is then welded by double-sided submerged arc welding and subjected to diameter expansion.

Available in a wide range of specifications, our DSAW pipe is characterized by large diameter, thick wall, high pressure resistance, low temperature resistance, and corrosion resistance. The weld is superior in toughness, plasticity, uniformity and compactness.

Application
The LSAW steel pipe is largely used for transporting oil, gas, coal slurry, ore pulp, and other materials onshore and offshore. It is also used as structural tube in ocean platform, power station, chemical engineering and urban construction.

Features
1. The LSAW steel pipe has one longitudinal welding seam.

2. It is easy to carry out nondestructive flaw detection during production and during use process for the welding seam.

3. By making use of pre-welding and then fine welding, the whole welding process is stable and the welding seam has high quality.

4. Processed with overall mechanical diameter expansion, the LSAW steel pipe enjoys small and evenly distributed internal stress, which can effectively prevent stress corrosion cracking. Also, the high dimensional accuracy brings convenience to site welding construction.

Production Process
1. Whole Plate Ultrasonic Inspection
2. Edge Milling
3. Edge Pre-bending
4. Forming
5. Pre-welding
6. Inside Welding
7. Outside Welding
8. Ultrasonic Inspection I
9. X-ray Examination I
10. Diameter Expanding
11. Hydrostatic Test
12. Chamfering
13. Ultrasonic Inspection II
14. X-ray Examination II
15. Tube End Magnetic Particle Inspection
16. Anticorrosion Treatment and Coating