1, with the eyes to see, there will be a very clear welding seam pipe diameter, its color and other parts of the pipe is different.

2, the chemical composition of the material analysis, the material of the pipe will be relatively poor, the content of impurities and harmful elements will be higher.

3, for mechanical analysis or process performance analysis, for flaring test, welded steel easy to crack.

4, eddy current testing, eddy current control welded steel pipe may be more alarm.