First, purchasing needs to understand the types of steel pipes:
1. By type: straight seam steel pipe, seamless steel pipe, spiral steel pipe, etc.
2. Sectional shape classification of straight seam steel pipes: square pipe, rectangular pipe, elliptical pipe, flat elliptical pipe, semi-circular pipe, etc.
Second, a few points to note:
In the early days of the steel pipe industry, there were many deceptive tricks, but now people are more proficient in this industry, so those tricks can be identified with our naked eyes.
1. The wall thickness of the steel pipe is not enough to use the gate method. If the mouth end of the steel pipe is shielded with a hammer, it will look thicker, but when measured with an instrument, the original shape will be revealed.
2. Use a straight seam as a seamless steel pipe. There are only a few longitudinal welds in the straight seam. Use a machine to polish the entire steel pipe, commonly known as polishing. It will look like there is no gap to act as a seamless steel pipe.
3. Nowadays, there is a more clever method which is seamless steel pipe. Seamless steel pipe is also a thermally expanded steel pipe. After the expansion, there is lead powder inside, and there are burn marks on the outside, but the weld seam cannot be seen. Many larger steel pipes use this kind of steel pipe to act as seamless and sell it to make big profits.
4. Girth welded straight seam steel pipes use polishing to produce seamless steel pipes and straight seam steel pipes.
Post time: Nov-21-2023