Spiral welded pipe uses a continuous helical seam, while longitudinal welded pipe has one or more straight seams running along the pipe length. The choice depends on diameter, wall thickness, standard, and production economics.
Material and Geometry
Spiral welded pipe can produce large diameters from a narrower strip, which improves material utilization and allows a wide range of sizes on one line.
Longitudinal welded pipe, including ERW and LSAW, uses a straight seam. LSAW is often selected for thick-wall, large-diameter pipe where a high degree of dimensional control is needed.
Practical Selection
For many water, piling, and utility projects, spiral welded pipe is the economical choice across DN200 to DN3800. For demanding high-pressure line pipe with very thick walls, longitudinal welded pipe may be preferred depending on the specification.
Side-by-Side Comparison
| Item | Spiral Welded | Longitudinal Welded |
|---|---|---|
| Seam | Continuous helical seam | Straight longitudinal seam |
| Material efficiency | Good for large diameters | Can require wider plate or strip |
| Typical process | SSAW | ERW or LSAW |
| Diameter | Large diameter emphasis | Small to large diameter range |
Key Takeaways
- Spiral welded pipe is often the best value for large-diameter non-critical or structural service.
- Longitudinal welded pipe may be preferred for thick-wall pressure service.
- Always match the welding method to the governing standard and inspection plan.