The Differences between ERW Steel Pipe and LSAW Steel Pipe
Straight seam welded steel pipe is divided into ERW steel pipe and LSAW steel pipe according to the welding process. ERW steel pipe is not formed in a hot melt state, but the weld metal undergoes a recrystallization process. No additions. Therefore, the chemical composition of the formed weld seam is completely consistent with the base metal. So the overall mechanical properties of the ERW steel pipe is better.
1. The difference on raw materials and production capacity
The raw material of ERW steel pipe is hot rolled coil, and the raw material of LSAW steel pipe is hot rolled sheet. Therefore, ERW steel pipe can do continuous pipeline operation with high production efficiency and low production cost; while LSAW steel pipe is processed by steel plate, can not do continuous pipeline operation so that the cost is higher.
ERW steel pipe is limited by the thickness of the coil. Generally, the maximum thickness that can be produced is 25mm and the maximum caliber is 660mm. The maximum thickness of LSAW steel pipe can be produced is 40mm and the maximum caliber is limited by the width of the steel plate, it is 1422mm now.
2. Welding Differences
ERW steel pipe welding does not need to add welding wire; LSAW steel pipe needs to add welding wire.
3. Differences in Appearance
When ERW steel pipe do corrosion protection, the welds has to removed; the internal and external welds of LSAW steel pipes are left with high level, which is not good for corrosion protection.
4.Procurement Cost Differences
ERW steel pipe cost is lower than LSAW steel pipe. The price difference is 15% -25%. When the diameter is less than Φ406mm, the difference in procurement costs is greater. When the diameter is less than Φ406mm, the purchase cost will be greatly reduced.
5. Application Differences
ERW steel pipes are mainly used for long-distance land transportation pipelines such as natural gas, refined oil, crude oil, and pulp. LSAW steel pipes are mainly used in high-pressure submarine long-distance pipelines, high-cold areas, and land types II, III, and IV.