Cause of the Welds in Trachoma

Spiral Pipe(ssaw steel pipe): by strip by roll forming machine, folding spiral direction, and then double-sided submerged arc welding is made through a capacitor. Spiral welded steel pipe production process, prone to leakage in many cases, such as welding and the wrong side. However, in these cases appear Chlamydia is the most difficult to master spiral steel butt weld. 

The so-called trachoma: that the welding process on the inside surface of the weld or welds, there has not been a thorough penetration of particles or bubbles, as well as the shape of the sand pit in the surface of the weld. The reason for trachoma are the following: 
1, the supply of the welding torch during the current is too small, the capacitor is too short, the capacitor has not been completely thorough when welding the welding surface has been hardened, so there occurs a penetration of sand or not bubbles. 
2, scimitar tune into the strip-shaped curvature of the time there is no good butt, butt strip does not match exactly, there has been too much of a gap between the butt strip. 
3, butt welded steel when the two sides have not cleared up the edge of the strip rust or scale. 
4, there is no timely maintenance of production equipment to clean up. Workbench dust or dirt, mistakenly fall into the gap at the butt welding of steel. 
5, the operating temperature is too low or too wet workshop, which affects the temperature and dryness of welding points.