LSAW Steel Pipe

Key Specifications
Diameter: 16 inches to 72 inches (406.4 mm to 1828.8 mm)
Wall Thickness: 6 mm to 60 mm

Length:5.8m/6m/11.8m/12m/18m/32m / Customized


Standards: API 5L, ASTM A53, ASTM A671, ASTM A252, EN10219, EN 10217

Material: API 5L Grade B, X42, X52, X60, X65, X70, S235，S275, S355, GR.1, GR.2, GR.3

Production Process
Plate Preparation: High-quality carbon steel plates are selected.
Forming: The plates are formed into a cylindrical shape using a UOE or JCOE process.
Welding: The longitudinal seam is welded using submerged arc welding (SAW).
Heat Treatment: Normalizing or quenching and tempering is performed.
Inspection: The pipes undergo rigorous testing, including ultrasonic and radiographic tests.

JCOE Process（JCOE工艺）

1. Forming Process

The JCOE process forms steel plates step by step in a J–C–O sequence through progressive pressing, gradually shaping the plate into a pipe.

2. Welding and Expansion
After forming, tack welding is performed using gas-shielded welding, followed by internal and external submerged arc welding (SAW), and finally full-body mechanical expansion to improve dimensional accuracy.

3. Cost and Flexibility
JCOE process offers lower equipment investment, reduced die wear, and strong adaptability for different pipe sizes, making it a cost-effective production method.

4. Production Efficiency
Due to multi-step forming, JCOE has lower efficiency compared with UOE, but it requires less tooling and lower capital investment.

5. Dimensional Accuracy
Compared with UOE, JCOE has slightly lower dimensional precision, which is why UOE is preferred for high-precision offshore pipeline applications.

UOE Process（UOE工艺）

1. Forming Process
UOE process involves edge beveling, plate pre-bending, U-forming, and O-forming to shape the steel plate into a pipe with high dimensional consistency.

2. Welding and Expansion
After forming, tack welding is performed using gas-shielded welding, followed by internal and external submerged arc welding (SAW), and final mechanical expansion to achieve precise geometry and stress relief.

3. Production Characteristics
UOE technology is a mature and highly stable process, offering excellent product quality, consistent specifications, and high production output.

4. Equipment Investment
UOE production requires large-scale equipment and higher capital investment compared to JCOE and spiral welded pipe production lines.

5. Weld Quality Advantage
UOE pipes have shorter weld seams compared to spiral welded pipes of the same length, resulting in a lower probability of weld defects and higher structural reliability.

Applications
Oil and gas transmission pipelines
Structural and heavy-duty applications
Water and sewage transportation

Advantages
High Strength: Suitable for high-pressure and large-diameter applications.
Durability: Excellent performance in harsh environments.
Customization: Available in various grades and specifications.