What is the defect in outer surface of the hot expanded seamless pipe?

The difference between high frequency welded steel pipe and straight-seam welded steel pipeFirst. Different in natureA. High-frequency welded steel pipe: After the hot-rolled coil is formed by the forming machine, the skin effect and proximity effect of the high-frequency current are used to heat an

Thanks for South Africa's new customer order in the coated welded steel pipe. These are the carbon steel welded pipes that will be shipped with the standard export package. All of us know that South Africa is the second economy. Citizens have a higher standard of living. South Africa's energy and t

Advantages of anti-corrosion steel pipe1. Combine the mechanical strength of the steel pipe with the corrosion resistance of the plastic;2. The outer wall coating is more than 2.5mm, resistant to scratches and bumps;3. The inner wall friction coefficient is small, 0.0081-0.091, which reduces energy