Features of LSAW steel pipe design

LSAW (Longitudinal Submerged Arc Welding) steel pipes are widely recognized for their unique design features, which contribute to their strength, stability, and efficiency in various applications. Here are the key features of LSAW steel pipe design.

Excellent Geometric Properties:
LSAW pipes have thin walls with material distributed around the centroid, resulting in a high radius of gyration and strong torsional stiffness. This design makes them ideal for use as compression, pressure-bending, and bi-directional bending members, offering superior load-bearing capacity. Additionally, the straightness and dimensional accuracy of cold-formed pipes are superior to those of hot-rolled open sections.

Superior Hydrodynamic Performance:
The circular cross-section of LSAW pipes provides optimal resistance to hydrodynamic forces, significantly reducing the effects of wind and water flow. In contrast, rectangular tube sections behave similarly to other open sections in this regard.

Corrosion Resistance:
Being a closed section, LSAW steel pipes have about 50% to 60% less exposed surface area compared to open sections, making them more resistant to corrosion and requiring less coating material for protection.

Efficient Node Connections:
LSAW pipes allow for direct welding at nodes without the need for additional plates or connectors, saving both labor and material costs.

Aesthetic Appeal:
The design of LSAW steel pipes, especially when used in pipe truss structures, is visually appealing with a modern, streamlined appearance that avoids unnecessary node connections.

Composite Capability:
If needed, LSAW pipes can be filled with concrete to form composite components, enhancing their structural performance.

These features make LSAW steel pipe structures highly efficient, allowing for a reduction of up to 20% in steel usage for industrial buildings and up to 50% in tower structures compared to open section designs. Depending on factors like component stress, availability, manufacturing conditions, and cost, LSAW pipes can be used as either round or rectangular structures, or a combination of both. Typically, rectangular pipes are used for chords, while round pipes are used for webs. In some cases, I-beams or H-shaped steel may be used for chords, with webs made of rectangular or round pipes.

The mechanical properties of LSAW pipes provide excellent stability, and while they may be prone to local buckling under pressure, they retain strength after buckling. This makes them highly advantageous in resisting hydrodynamic forces. Additionally, their minimal surface area, combined with a lack of edges and corners, makes them highly resistant to corrosion and fire, offering economical use of fire-resistant and anti-corrosion materials.