What are the advantages and disadvantages of ERW welded pipe compared to seamless pipe?

Shijiazhuang Faith MachineryCo.,Ltd receives frequent enquiries from engineers and procurement teams asking how ERW (electric resistance welded) pipes compare with seamless pipes. Both types have well-established roles in industry; the choice depends on the application,mechanical requirements, cost targets and available inspection regimes. 

This article lays out the main advantages and disadvantages of ERW welded pipe versus seamless pipe so readers can make more informed specification and procurement decisions.

Advantages of ERW welded pipe

1. Cost and material efficiency

·ERW pipe production starts from strip or coil stock and forms tubes by edge-joining,which typically results in lower raw-material cost per linear metre compared with drilling or extrusion used for seamless pipe. For many standard diameters and wall thicknesses,ERW is more economical to produce at scale.

2.High production throughput

·Modern ERW lines produce long continuous runs with high line speeds, enabling large-volume output and consistent dimensional control. This makes ERW attractive where continuous supply and competitive unit cost are priorities.

3. Tighter dimensional control for certain ranges

·With appropriate sizing and stretch-forming, ERW pipe can achieve consistent outer diameter and wall-thickness tolerances. For many structural and general-purpose applications these tolerances are adequate and repeatable.

4. Flexibility of materials and coatings

·ERW lines are adaptable to a wide range of strip feedstocks (cold-rolled, hot-rolled, galvanized, pre-painted) and can be configured with inline finishing (scarfing,coating, annealing) to meet different end-use requirements.

5. Lower scrap for certain product mixes

·Coil-fed production minimizes some types of scrap (compared with billet piercing for seamless) when producing many short or mid-length runs from standard coil sizes.

Disadvantages of ERW welded pipe

1. Weld seam is a potential performance concern

·The presence of a longitudinal weld seam means the product is not metallurgically homogeneous across the cross-section. Depending on welding quality and subsequent treatment, the seam can exhibit different mechanical properties or be a locus for corrosion if not properly treated.

2. Limitations for high-pressure, high-temperature or critical service

·For high-pressure service (e.g., certain oilfield, high-pressure boilers) or rotating/high-fatigue components, many end users prefer seamless pipe because it lacks a longitudinal seam and can offer more uniform mechanical properties through the wall.

3. Upper limits on diameter and thickness for economical ERW production

·ERW is most economical in small- to medium-diameter ranges and moderate wall thicknesses. Very large diameters or very thick walls are often handled more economically by seamless or alternative welded processes.

Practical selection guidance

·Use ERW when cost, volume, and dimensional consistency are primary drivers and the operating conditions (pressure, temperature, cyclic loading) are within the validated envelope of the ERW product and inspection program.ERW is commonly used for structural tubes, scaffolding, furniture, lower-pressure pipelines, and many mechanical components.

. Use seamless when the application demands a homogeneous through-thickness structure(high pressure, high temperature, critical hydrocarbon service, some rotating parts) or when standards explicitly require it.

·Mitigation approach: When project constraints favour ERW but the application is demanding, combine ERW production with enhanced process control, post-weld heat treatment or localized tempering, and rigorous NDT to close the performance gap.