Differences between ERW and LSAW steel pipes

ERW steel pipes (Electric Resistance Welding steel pipes) and LSAW steel pipes (Longitudinally Submerged Arc Welded steel pipes) are both types of straight seam welded pipes primarily used for fluid transportation, especially for long-distance oil and gas pipelines. Here are the key differences between ERW and LSAW steel pipes:

ASME B36.10 ASTM A53 GR.B BE ERW pipes

ERW Steel Pipes (Electric Resistance Welded Pipes)

ERW steel pipes are manufactured using high-frequency welding techniques, including induction welding and resistance welding. The process starts with hot-rolled wide coils, which are continuously formed, bent, welded, heat-treated, sized, straightened, and cut. ERW pipes have several advantages:

1.Shorter Weld Seam: ERW pipes have shorter weld seams, which improves their integrity and reduces the chance of defects.

2.High Dimensional Accuracy: These pipes maintain a consistent diameter and uniform wall thickness, making them precise and reliable.

3.Good Surface Quality: The production process ensures smooth and high-quality surface finishes.

4.High Pressure Tolerance: ERW pipes are designed to withstand high pressure, making them suitable for specific applications.

However, ERW pipes are limited to producing medium and small-diameter pipes with thinner walls. Fusion and groove corrosion defects can also occur. These pipes are widely used for transporting natural gas and crude oil products in urban settings.

LSAW Steel Pipes

LSAW Steel Pipes (Longitudinal Submerged Arc Welded Pipes)

LSAW pipes use single medium-thick plates as raw materials. The steel plate is pressed or rolled into shape using molds or forming machines and then welded using a double-sided submerged arc welding (SAW) process. The key characteristics of LSAW pipes include:

1.Wide Range of Specifications: LSAW pipes are available in a full range of specifications to meet various requirements.

2.Good Toughness and Plasticity: These pipes have excellent toughness and plasticity, which enhances their performance in demanding applications.

3.Uniform and Dense Welds: The double-sided SAW process ensures that the weld seam is uniform, dense, and reliable.

4.Suitable for Large Diameters and Thick Walls: LSAW pipes can be produced with large diameters and thick walls, making them suitable for high-pressure, high-temperature, and corrosion-resistant environments.

LSAW pipes are often used for high-strength, high-toughness, and high-quality long-distance transportation of oil and gas. In compliance with API standards, LSAW pipes are the only specified type for major pipelines crossing regions such as extremely cold areas, underwater locations, and densely populated urban zones.

Depending on the forming method, LSAW pipes are classified into UOE, JCOE, and HME types, each offering unique features to suit specific pipeline requirements.