How to Distinguish ERW Steel Pipe and SSAW Steel Pipe?

ERW steel pipe is a steel pipe produced by using the skin effect and proximity effect of high-frequency current to heat and melt the edge of the pipe blank after the hot-rolled coil is formed by the forming machine, and then pressure-welded under the action of the extrusion roller. The ssaw steel pipe is made by rolling the low-carbon carbon structural steel or low-alloy structural steel strip at a certain helical angle (called the forming angle) into a tube blank, and then welding the pipe seams. Strip steel produces large diameter pipes. Although they all belong to a type of welded pipe, there are certain differences. So how to distinguish erw steel pipe and ssaw steel pipe?

1. From the point of view of production process

The strength of the ssaw steel pipe is generally higher than that of the erw steel pipe, and it can use a narrower blank to produce a welded pipe with a larger diameter, and can also use a blank of the same width to produce welded pipes with different diameters. However, compared with the same length of straight seam pipe, the length of the weld is increased by 30~100%, and the production speed is lower. Therefore, most of the welded pipes with smaller diameters use straight seam welding, and most of the welded pipes with large diameters use spiral welding.

2. From the point of view of advantages and disadvantages

The advantage of the ssaw steel pipe is that the strip steel of the same specification can be processed into steel pipes of various diameters. Poor, the length of the weld is longer than that of the straight seam pipe, and it is easy to form welding defects such as cracks, pores, slag inclusions, and welding deviations, and the welding stress is a state of tensile stress.

Compared with the ssaw steel pipe, the advantages of the erw steel pipe are that the welding seam is short, the dimensional accuracy is high, and the wall thickness is uniform; It is easy to form gray spots, unfused, groove-shaped corrosion defects, etc. at the seam. Now this kind of welded pipe is more used in city gas, crude oil and refined oil transportation.

3. From the price point of view

Due to the high material and technical performance and production technology requirements of hot-rolled coil, on the one hand, there are fewer domestic manufacturers that meet the standards than steel plate manufacturers. On the other hand, its production process and quality level determine its market price. Rolled steel plate, which is the main reason why the market price of ssaw steel pipe is higher than that of erw steel pipe. For the composition of the sales price of steel pipes, the material price is the dominant or even decisive factor.

Carefully examine the price difference between the ssaw steel pipe and the erw steel pipe. The price of the ssaw steel pipe is slightly higher than that of the erw steel pipe due to the price difference of the main materials. However, the production of steel pipes is only a part of the project. If the overall quality of the project, the overall project cost and other factors are considered, the ssaw steel pipestill has overall advantages.