LSAW (Longitudinal Submerged Arc Welded) and ERW (Electric Resistance Welded) steel pipes exhibit significant differences in various aspects. Below is a detailed comparison of these two types of steel pipes.
I. Manufacturing Process
- LSAW Steel Pipe
- Raw Material: Single sheets of medium-to-thick steel plates.
- Process: The steel plate is pressed (rolled) into a pipe blank in a mold or forming machine, and then subjected to double-sided submerged arc welding and expanding to form the final product.
- ERW Steel Pipe
- Raw Material: Hot-rolled wide steel strip coils.
- Process: The steel strip undergoes pre-bending, continuous forming, welding (high-frequency electric resistance welding, which can be divided into induction welding and contact welding), heat treatment, sizing, straightening, cutting, and other processes to produce the final pipe.
II. Product Characteristics
- LSAW Steel Pipe
- Offers a wide range of finished specifications, capable of producing large-diameter, thick-walled steel pipes.
- The weld seam exhibits good toughness, plasticity, uniformity, and compactness.
- Features large diameter, thick wall thickness, high pressure resistance, low-temperature resistance, and strong corrosion resistance.
- ERW Steel Pipe
- Offers high dimensional accuracy, uniform wall thickness, and good surface quality.
- The weld seam is short and capable of bearing high pressure.
- However, it can only produce small-to-medium diameter, thin-walled pipes (depending on the size of the steel strip or steel plate used as raw material).
- The weld seam is prone to defects such as gray spots, incomplete fusion, and groove corrosion.
III. Application Scenarios
- LSAW Steel Pipe
- Primarily used in the construction of high-strength, high-quality, long-distance oil and gas pipelines.
- According to API standards, LSAW steel pipes are the only specified pipe type for Class 1 and Class 2 areas, such as high-altitude, cold regions, seabeds, and densely populated urban areas, in large-scale oil and gas transmission pipelines.
- ERW Steel Pipe
- Widely used in urban gas, crude oil, and refined oil transportation.
- Due to its high dimensional accuracy and uniform wall thickness, it is also suitable for applications with high requirements for pipe size and wall thickness.
In summary, LSAW and ERW steel pipes differ significantly in manufacturing process, product characteristics, and application scenarios. The choice of which steel pipe to use depends on specific usage requirements and scenarios.
