The appearance of gaps refers to the phenomenon that the welds are not bonded together. The length of the gaps is generally more than a few centimeters or even longer. The main reasons are as follows:(1) Pass wearAs the extrusion roll hole pattern wears, the hole pattern (R) size gradually becomes l

Sand-hole pipes are also a kind of quality accident caused by weld leakage, but their gaps are very small, some of them cannot be directly observed by human eyes, and must be found through testing equipment, so we call this kind of pipes sand-hole pipes. The main reasons for sand hole pipes are as f

(1) The hole type does not matchThere are two-roller, three-roller and four-roller weld seam extrusion structures. As long as the combined hole shapes do not match, it is easy to cause scratches on the surface of the tube blank, especially the two-roller structure.There are many factors that cause t