Notes on purchasing smls pipe
1. Material problem of seamless steel pipe
Many companies use more material materials, usually refers to the amount of nickel. Although it can be used to distinguish medicine, it is clear that this is a misunderstanding, because the small charge of nickel containing only more than 7 can not distinguish out. But the price difference between raw materials is very large, this is one of the fake. Especially 321 high nickel and 316 high nickel fake is very serious.
2. Size problem of smls pipe
Many customers are basically no technical support for testing. For example, 90 degrees elbow, the conventional is R = 1.5D, but look at the Wenzhou market is basically more than 1.25D mold production, do not underestimate the 0.25D ~ ~ inside the weight of the material, but the difference is very large. Which is the so-called factory standard, much shorter than the standard.
3. Thickness problem of smls pipe
Of course, now the customer is very smart, will use caliper to the amount of thickness, although sometimes customers feel after the barely compliance, but ignored a little, that is, the thickness of the back arc is not enough! Because the elbow push process will be cut, so caliber barely compliance
4. Solution treatment and non-destructive testing of sand and sand processing and sandblasting of smls pipe
Many manufacturers on the market is not solution treatment and 100% penetration of non-destructive testing, which also has a lot of sandblasting instead of sand, save these steps, greatly reducing the cost.
5. Seamless welding
Welding seamless, is to do welding elbow, after grinding and pickling after sandblasting, the surface without any signs of welding, or even the use of advanced detection equipment can not see it is welding elbow.
6. Spot welding, repair welding
Elbow push process will appear thinning, so under normal circumstances manufacturers will use thicker pipe. If you use thin raw materials, that produced certainly unqualified. Under normal circumstances thinning about 40 silk, such as poor technology or the use of drawn pipe, the thickness is significantly lower than the standard a lot.