The strength of the spiral welding pipe is generally higher than that of the straight seam welded pipe. It can use a welded pipe with a larger diameter of the billet material, and can also use the same width to produce tube with different welding pipes with different billet production pipes. However, compared with the same length of the same length, the length of the weld is increased by 30 ~ 100%, and the production speed is lower. Therefore, most of the smaller -caliber welded pipes are welded with straight seams, and most of the large -caliber welded pipes are mostly spiral welded.
The appearance of the spiral welded weld must not have defects such as arcs, burning, cracking, scars, folding, and arc pits. The shape of the weld should be average, and the transition is gentle. The welding seam classification of spiral welding steel pipes has the following:
Steel belt pair welding weld: Steel belt -tap welding seam is the welding seam connected to the steel plate or the tail of the steel belt header of the spiral seam
Docking welded seam: It is the ring welded cramps that are connected to two steel pipes together
Positioning welding seam: It is used to fix the welded seams that fix the edges before the final welding, and heat the two edges of the pipeline to the welding temperature. Under the squeeze of the squeeze roller Immersing and crystallization ultimately constitute a strong welding seam.
So how to judge the quality of the spiral tube from the appearance?
The appearance inspection of the spiral tube welding joint is a cumbersome and commonly used inspection method, and it is an important part of the test. It is mainly to find the defects and bias of the appearance of the weld. After the naked eye inspection, it is tested with tools and other tools. If the appearance of the weld is defective, there is a possibility of defects inside the weld.
