There are many processing steel pipe operators reflect the spiral steel pipe butt weld at the presentation of trachoma. Spiral steel pipe is made of strip steel through the roll forming machine, the spiral direction of bending, and then through the capacitive double-sided submerged arc welding. In the spiral steel pipe welding production process, simply present a lot of conditions such as leakage welding and misalignment. But in these conditions * difficult to grasp is the spiral steel pipe butt weld at the presentation of trachoma. The so-called trachoma: that is, the welding process in the welding seam exterior or weld inside, presenting particles or bubbles that have not been completely melted through, as well as the appearance of the weld in the shape of sand pits.
 
Spiral steel pipe plant analyzes the causes of the presence of trachoma are as follows.
 
1, the current supplied to the welding gun in the welding process is too small, the capacitor moment is too short, the welded surface is now hardened when the capacitor has not been completely welded through, so the inside presents the sand grains or bubbles that have not been welded through.
 
2, the strip into the scimitar type shaped arc when there is no good docking, the strip docking is not tightly seamed, and the docking strip presents too much open space between.
 
3, butt welding strip, there is no timely finishing strip rust or perhaps oxide skin on both sides of the edge.
 
4, production equipment is not timely maintenance and finishing. Dust or perhaps dirt on the workbench, mistakenly fall into the welding gap of the butt welded strip steel.
 
5, the operation workshop temperature is too low or perhaps too wet, and then affect the temperature and dryness of the weld point.