Comparative Analysis of Galvanized ERW Pipe and Galvanized Seamless Pipe

Galvanized ERW welded steel pipe and Galvanized seamless steel pipe have significant differences in manufacturing process, performance characteristics, dimensional accuracy, cost differences and application areas. The following is a detailed comparative analysis of the two:

1. Comparison of manufacturing process
Galvanized ERW pipe is welded by curling steel plate or strip and welding it using high-frequency resistance welding process technology. This manufacturing method may cause the performance and corrosion resistance of the weld to be different from other parts of the pipe body. In contrast, galvanized seamless steel pipe is made by hot rolling or cold drawing process, has no welds as a whole, and is galvanized to improve its corrosion resistance.

2. Differences in steel pipe characteristics
Although the performance of galvanized ERW pipe at the weld position may be slightly affected, its comprehensive performance can meet most application scenarios under normal use environment. The advantage of galvanized seamless steel pipe is its uniformity of strength and overall performance, which can cope with higher pressure and load. At the same time, the uniformity of the galvanized layer also provides it with excellent anti-corrosion effect.

3. Differences in dimensional accuracy and cost
Galvanized ERW pipes have high dimensional accuracy, relatively uniform wall thickness (controlled by cold-rolled strip steel), high cost performance, and are suitable for large-volume purchases. Galvanized seamless steel pipes have large wall thickness deviations for hot-rolled pipes, complex processes, and high costs, making them suitable for key parts.

4. Different application scenarios
Galvanized ERW pipes are widely used in many industries such as construction, machinery, and chemicals due to their relatively low production costs, and are especially suitable for low-pressure fluid transmission and structural support. Galvanized seamless steel pipes are more often used in extreme environments, such as petrochemicals, electricity, and nuclear energy, because they can meet more stringent conditions of use.

Selection suggestions:

Choose galvanized ERW welded pipes in the following situations:

Budget is limited and high pressure is not required (such as building scaffolding, drainage system)
Large-volume standardized procurement is required (such as municipal pipe network)
Small and medium-sized diameter (DN≤300mm) low-pressure fluid transportation

Choose galvanized seamless steel pipes in the following situations:

High-pressure/high-temperature working conditions (such as boiler pipes, hydraulic systems)
Occasions with extremely high safety requirements (such as gas main pipes)
Special corrosive environments (with thick galvanized layer or composite anti-corrosion)

Technical supplementary instructions:

1. Weld inspection: Welded pipes need to be tested by eddy current or ultrasonic flaw detection (UT) to ensure quality.
2. Galvanizing process differences: Seamless pipes usually have thicker walls, so the galvanizing time needs to be extended (about 30%).
3. Emerging technologies: Some high-end welded pipes use laser welding (LSW), which is close to seamless pipes in performance.

The best choice can be made by comprehensively considering cost, working conditions and service life. In general civilian areas, galvanized welded steel pipes are sufficient to meet the needs; while in key industrial areas, seamless pipes are still an irreplaceable choice.

Read more: Hot-dip Galvanized Seamless Pipe Production Process or ERW pipe vs Seamless pipe