What is internal welding flatness of seamless steel pipe（https://www.eastern-steels.com/product/seamless-steel-pipe.html）?

Seamless pipes have strict requirements on cavity cleanliness and wall thickness tolerances. However, during the entire electric welding process, due to the action of molten metal materials, the thickness of the pipe at the weld will increase, making the inside and outside of the weld uneven.

Reasons why seamless steel pipes are uneven during welding
1. Generally, when welding a circle, the angle of view of the welding wire will change.
2. When the metal melts, the vertical position of the seamless steel pipe will produce an annoying development trend, resulting in weld marks.
3. When seamless steel pipes are welded vertically, there will be water droplets inside, and uneven penetration will occur.

Uneven internal and external welding will lead to increased energy consumption of the conveyor. At this time, internal welding floor leveling technology must be used. That is, the "seamless splicing" of seamless pipes can be completed according to the flipping frequency and compressive strength. After the internal welding is rolled with a straightening roller, the cross section of the pipe becomes a horizontal oval, and the journal is stuck in the pipe and follows the pipe. After vertical mixed cold rolling, the pipe section becomes circular. When the sound card frame returns, the journal is separated from the pipe and pulled back to the appropriate position by the cylinder, realizing a secondary cold rolling cycle system. After continuous squeezing, the inner cavity of the tube will become smoother and smoother.

Advantages of Internal Weld Correction Technology
1. Seamless pipes using internal welding correction technology are less likely to retain chemical substances on the inner wall, preventing the accumulation of liquid or corrosive chemicals due to welding;
2. Easy to clean and avoid bacterial growth;
3. The inner cavity has excellent corrosion resistance.

In addition, especially when the pipeline is used in the liquid and food industries, the inside of the pipeline must be parallel to prevent the liquid from causing blockage of the pipeline. At present, the application range of this type of internal welding straightening technology is between diameter 12-219. It should also be noted that seamless pipes of the same specification are equipped with a set of leveling rollers and vertical rollers, while pipes of the same specification but with different wall thicknesses are equipped with different journals.