🔧 Differentiating Between Straight Seam, ERW, and Spiral Welded Steel Pipes

Steel pipes are essential in modern infrastructure, energy, and water transmission projects. Broadly, they can be classified into two main types: seamless pipes and welded pipes. Welded pipes are further divided into straight seam, electric resistance welded (ERW), and spiral welded pipes. Each type has unique manufacturing methods, applications, and advantages.

⚡ Electric Resistance Welded (ERW) Pipes

ERW pipes are produced using high-frequency induction welding. The edges of the steel strip are heated by high-frequency current (skin effect and proximity effect) and then pressed together to form a weld.

Key Advantages:

• ✅ Stronger weld: made from the steel strip’s base material itself.

• ✅ Smooth surface and accurate dimensions → ideal for coating applications (3LPE, FBE, epoxy).

• ✅ High production efficiency & lower costs compared to seamless pipes.

• ✅ Used widely in oil & gas transmission, power plants, automotive, and structural projects.

  
  

➖ Straight Seam Welded Pipes

A straight seam welded pipe has a weld seam running parallel to the pipe’s axis. ERW pipes belong to this group, but not all straight seam pipes are ERW.

Key Advantages:

• ✅ Simplified and efficient production.

• ✅ Lower costs and faster output than spiral welded pipes.

• ✅ Commonly used in water supply, drainage, petrochemical, agricultural irrigation, urban construction, piling, bridges, and structural works.

  
  

🔄 Spiral Welded Pipes (SSAW / HSAW)

Spiral welded pipes are produced by forming hot-rolled coil into a spiral shape, then welding along the spiral seam.

Key Advantages:

• ✅ Can produce large-diameter pipes (up to DN 3000 mm) using narrower coil strips.

• ✅ Flexibility to manufacture different diameters using the same coil width.

• ✅ Strong weld performance, ideal for long-distance pipelines.

• ✅ Common in water transmission, oil & gas trunklines, marine projects, and piling applications.

Considerations:

• Weld seam length is 30–100% longer than straight seam pipes → slightly higher inspection and testing requirements.

• Production speed is slower, but the ability to meet very large diameter demands makes them indispensable for mega-projects.

📊 Straight Seam vs. ERW vs. Spiral Welded Pipes

Feature	Straight Seam	ERW	Spiral Welded
Welding Method	Arc welding / ERW	High-frequency resistance welding	Submerged Arc Welding (SAW)
Diameter Range	Small–medium DN	Small–medium DN	Large DN (up to 3000 mm)
Strength	Good	Strong, smooth weld	High strength for trunklines
Applications	Water supply, construction, structures	Oil & gas transmission, industrial	Long-distance pipelines, water projects, piling
Production Speed	Fast	Very fast	Slower
Cost Efficiency	High	High	Moderate

🎯 Application Summary

• ERW Pipes → Best for oil & gas transmission, high-precision industrial applications.

• Straight Seam Pipes → Ideal for water, structural, and cost-driven projects.

• Spiral Welded Pipes → Perfect for large-diameter, long-distance water and oil & gas transmission projects.

  
  

🔗 Pipekom’s Expertise

At Pipekom, we supply the complete range of welded and seamless steel pipes for global infrastructure projects. Our solutions include:

✅ Spiral Welded Pipes (SSAW/HSAW) — DN 400–3000 mm for long-distance water and oil & gas transmission.

✅ ERW Pipes — high-frequency welded, smooth surface for oil & gas, industrial, and structural use.

✅ Straight Seam Pipes — cost-effective for water supply, construction, piling & bridges.

✅ Seamless Pipes & OCTG — for upstream oil & gas and high-pressure applications.

✅ DI, HDPE & GRP Pipes and Fittings — for municipal water, sewage, and stormwater networks.

✅ Valves, Fittings & Coatings (3LPE, FBE, epoxy, PU) — complete pipeline packages.

✅ Engineering & Logistics — BoQ prep, hydraulic calculations, inspections, CIF/CFR/DDP delivery to 20+ countries.