Spiral pipe surface quality problems mainly in the surface oxide thick, surface cracking, heavy leather surface, surface mechanical bumps and so on. Hot-rolled carbon steel pipe after completion, after, or cold-rolled steel and then heat treated, will form a layer thick and strong adhesion, high temperature oxide. The presence of oxide steel look not only poor quality, also affect the use of steel, which is the standard are not allowed. Such oxide with the general sandblasting is difficult to remove, to use pickling or mechanical polishing method to clear.

Mechanical bruising is the most common quality problems, arising primarily from the production, handling and transportation. Pipe bumps are formed at a structural discontinuities, use is a source of stress concentration, but also chipped sensitive. Compared with crack, mechanical defects bruised outline clear, do not involve injuries metal, so the standard allows some bumps depth exist, but in some of the more sensitive application conditions, or deeper than a certain value bruised , it should be ground to eliminate so smooth transition.