ERW Steel Pipe is different from UOE Steel Pipe, the difference are as follows:

1. The Raw Materials and Production Capacity Difference
The material for producing ERW Steel Pipe is hot-rolled coil or strips, while for producing UOE Steel Pipe we use hot-rolled steel. Therefore, ERW Steel Pipe can achieve a continuous pipeline operations, high production efficiency, low production costs. For UOE Steel Pipe, it can not achieve a continuous pipeline operations, low productivity, high production cost. The maximum thickness for ERW Steel Pipe can reach 25mm, and the maximum outside diameter for ERW Steel Pipe can achieve 660mm. However, the maximum wall thickness for UOE Steel Pipe is 40mm, and the maximum production outside diameter is limited by the width of the steel sheet, in current day, the maximum production outside diameter for UOE Steel Pipe is 1422mm.
2. Welding Difference
Compared with UOE Steel Pipe, one of the advantages of ERW Steel Pipe is that there is no need to have additional wire during the welding process. 
3. Appearance Difference
During the production process, ERW Steel Pipe requires inside and outside welds remove, so it has a anti-corrosive advantages compared with UOE Steel Pipe. 
4. Application Difference
ERW Steel Pipe is mainly applied in natural gas, refined oil, crude oil, pulp and other terrestrial long-distance pipelines. UOE steel pipes are mainly used in high-voltage submarine long-distance pipelines, alpine area, land two/three/four types of areas.