According to the standard, welding seam have three levels, and the price of each level is different.

The first-level welding seam can be seen from the inspection to see whether there are impurities in the weld and the allowable repair length of the first-level inspection is very small. Generally, the structure straight seam steel pipe and the straight seam steel pipe for piling uses the first-level inspection straight seam pipe.

The second-level flaw detection welding is allows several repairs, which is looser than the first-level.

The third-level welding seam is the same as the CB3091 standard. It is impossible to judge the quality of the steel pipe welding seam by eyes. So we can use ultrasonic non-destructive testing. It used in many construction sites to test the steel pipe link.

Above are the grade of structure straight seam steel welded pipe that Xiangjia Metal Material Co., Ltd. summary for you. Looking for more things about steel pipe, you can click here: http://www.xiangjiasteel.com/news.html