Our product
What’s LSAW Steel Pipe
LSAW Steel Pipe is produced using a single heavy steel plate as raw material. The plate is formed into a cylinder and welded along a single straight longitudinal seam. Known for its high strength and thick walls, LSAW is the “heavy-duty” choice for high-pressure energy pipelines and critical structural applications where dimensional precision is paramount.
Advantages of LSAW Steel Pipe
- High Pressure Resistance: The longitudinal seam design, combined with thicker plate materials, allows these pipes to withstand extreme internal pressures.
- Superior Dimensional Accuracy: After welding, the pipes undergo mechanical expansion, ensuring perfect roundness and diameter consistency.
- Heavy Wall Capability: Unlike ERW or SSAW, LSAW can reach wall thicknesses of 60mm or more, making it indispensable for deep-sea and high-stress environments.
- Low Residual Stress: Our expansion process relieves internal stresses generated during forming and welding, improving the pipe’s lifespan.
LSAW Pipe Specification
| Size Range | Outer Diameter: Φ406.4mm~Φ1422.4mm (common large-diameter line pipe) |
| Size Range | Length: 5.8m~12.5m (standard single length) |
| Wall Thickness Range | Conventional: 6mm~50mm (deep-sea pipelines can reach over 40mm) |
| Wall Thickness Range | Special Requirements: 1.5mm~60mm (customized based on project requirements) |
| Pressure Rating | Applicable Standards: API 5L PSL1/PSL2, ISO 3183-3 |
| Pressure Rating | Steel Grades: L245~X80 (yield strength 245MPa~555MPa) |
| Material | Carbon Steel and Alloy Steel |
| Processing | UOE/JCOE |
| Testing | Water Column Ultrasonic Testing + Industrial X-ray Television Inspection |
| Performance | Resistant to hydrogen-induced cracking and sulfide stress corrosion, high-temperature resistance, and adaptable to deep-sea environments. |
The manufacture and production of SSAW pipe cannot be separated from international standards and guidance.
| Small diameter steel pipe | Medium diameter steel pipe | Large diameter steel pipe | ||||||
| O.D.(mm) | W.T. (mm) | Process | O.D.(mm) | W.T. (mm) | Process | O.D.(mm) | W.T. (mm) | Process |
| 406.4 | 6.0-40.0 | UOE/JCOE | 800 | 12.0-50.0 | Chemical pipelines/structural support | 1422.4 | 20.0-60.0 | JCOE only (UOE maximum 1620mm) |
| 508 | 8.0-50.0 | JCOE | 1016 | 18.4-33.0 | High-pressure oil and gas trunk lines (X80) | 1524 | 25.0-60.0 | Non-standard customization available |
| 610 | 10.0-60.0 | JCOE | 1219 | 18.4-50.0 | Deep-sea/polar projects |
LSAW Manufacturing Process (JCOE Method)
- Plate Ultrasonic Testing: The raw steel plate is first inspected for internal defects.
- Edge Milling: Both longitudinal edges of the plate are milled to a specific V-groove shape.
- JCO Forming: A heavy hydraulic press bends the plate step-by-step into the J-C-O shape.
- Pre-welding & SAW: The pipe is tack-welded, followed by high-power internal and external submerged arc welding.
- Mechanical Expansion: A specialized expander is inserted to increase the diameter slightly, ensuring perfect roundness and relieving stress.
- Final Inspection: Rigorous testing, including hydrostatic and radiographic checks, confirms the pipe is ready for high-pressure service.
UOE LSAW Pipe Forming Process
