Description

For manufacturing LSAW steel pipes to specified standards, the selection of high-strength steel plates is crucial. We ensure quality and performance by matching steel grades and thicknesses precisely to the required pipe dimensions.

Here’s a breakdown of recommended steel sheet specifications for various pipe sizes and grades: [This section will contain a detailed table or list, specifying which steel plate grade and thickness is appropriate for each LSAW pipe size and grade. For example: “For X52 grade, use X mm thick plates. For X60 grade, use Y mm Thick plates, etc.”]

By utilizing the correct materials, we guarantee the structural integrity and longevity of our LSAW pipes, meeting the demanding needs of diverse applications and industries. Contact us to learn more about our comprehensive LSAW pipe solutions.

1. Required Mild Steel Plates for LSAW Pipes

Steel Grade: API 5L X65 / S460 (High Strength for Structural & Offshore Applications)

Steel Grade: API 5L X52 / EN 10219 / S355J2H (High Strength, Structural Applications)

Steel Grade: API 5L X52 / S420 (Heavy-Duty Piling Applications)

2. Steel Plate Selection Criteria

To ensure quality LSAW pipe manufacturing, the steel plates must have:

• Good weldability (low carbon equivalent for better welding properties).
• High yield & tensile strength to match the API & EN standards.
• Controlled thickness tolerance for precise welding and bending.

3. Recommended Steel Plate Standards

4. Manufacturing Process for LSAW Pipes

1. Steel Plate Cutting – Cut to the required width for pipe diameter.
2. Edge Beveling – Prepared for submerged arc welding (SAW).
3. Forming (Bending / Pressing) – Converted into “J”, “C”, and “O” shape.
4. LSAW Welding – Submerged Arc Welding (SAW) to ensure high-quality, durable welds.
5. Ultrasonic & Radiographic Testing – Ensures weld integrity and strength.

For material sourcing and fabrication details for manufacturing LSAW (Longitudinal Submerged Arc Welded) steel pipes, we have to break it down into three key areas:

1. Material Sourcing: Where & How to Source Steel Plates
2. Fabrication & Welding Process
3. Testing & Quality Control

Fabrication & Welding Process for LSAW Pipes

Once you procure the right steel plates, the LSAW pipe manufacturing process involves these steps:

Step 1: Steel Plate Cutting & Edge Preparation

• Plates are cut to the required width based on the pipe diameter.
• Edge beveling is done to prepare for welding.

Step 2: Pipe Forming (Press Bending / Roll Bending)

• Steel plates are shaped into a cylindrical form using the JCOE method:
  • J-forming → C-forming → O-forming
• Large-diameter pipes (e.g., 1800 mm OD, 40 mm thick) are formed in multiple steps using a press.

Step 3: Longitudinal Submerged Arc Welding (LSAW)

• Pipes are welded in two stages:
  • Inside welding – First weld pass inside the pipe.
  • Outside welding – Final weld pass externally for reinforcement.
• Automatic submerged arc welding (SAW) is used for strong, defect-free welds.

 Welding Consumables:

• Electrode: AWS A5.17 EM12K or A5.23 F7A2-EM12K
• Flux: Lincoln 801/880 or ESAB OK 10.81

3. Testing & Quality Control for LSAW Pipes

To meet API 5L & EN standards, pipes undergo rigorous testing before dispatch:

A. Non-Destructive Testing (NDT)

1. Ultrasonic Testing (UT) – Detects internal weld flaws.
2. Radiographic Testing (RT/X-ray) – Ensures full penetration welds.
3. Magnetic Particle Testing (MPT) – Checks surface cracks.

B. Destructive Testing

1. Tensile Test – Verifies steel’s yield & tensile strength.
2. Charpy Impact Test – Ensures toughness at low temperatures.
3. Hardness Test – Confirms compliance with API & EN requirements.

C. Dimensional & Hydrostatic Testing

• Pipe ovality & straightness check
• Hydrostatic Pressure Test at 1.5x working pressure

 Certification Required:

• EN 10204 3.1/3.2 Mill Test Certificate (MTC)
• API 5L PSL2 Compliance for oil & gas pipelines