Spiral submerged arc welded pipe often appear in the production and use of some quality problems affect the normal use, in some areas, the need for spiral welded pipe to determine the quality, according to certain methods and performance tests, can play a significant role in the actual use , Then how to identify fake and shoddy spiral pipe method: appearance often ma face phenomenon. In general, the overall ratio is better, mainly considering the problem of cumulative error and probability theory. Please add some of the above, if insufficient, we welcome everyone to discuss the knowledge of steel pipe, continuous improvement of exchange. Pock is due to severe wear groove spiral welded pipe irregular irregularities caused by defects. Because fake and inferior spiral welded pipe manufacturers have to pursue profits, rolling trough the most often exceeded. The surface is very easy to produce scars.
Spiral welded pipe of uniform quality. High-tonnage cold shear machine, cutting head end smooth and flat surface, poor material, due to poor material, cutting surface often have the phenomenon of meat, that is uneven, and no metallic luster. And because cut corners of manufacturers cutting products less head and tail will be big ears. Diameter fluctuations. The various spiral welded pipe surfaces formed by folding often run the length of the entire product. As a result of shoddy shoddy, the pursuit of high efficiency manufacturers, too much discount, resulting in the ears rolling off the fold, the product will appear when bending bending cracking, strength, spiral welding dropped significantly. Very easy to scratch.
The reason is that poor quality materials manufacturers crude equipment, easy to produce burrs, scratched the surface of spiral welded pipe. Deep scratches reduce seamless steel pipe strength. Easy to fold. Transverse ribs thin and low. Often there is enough dissatisfaction with this phenomenon, because manufacturers want to achieve a large negative tolerance, before the completion of the reduction of a few relatively large, small iron, pass enough dissatisfaction. Cracking. The reason is that it is blank brick, brick multi-porosity, brick in the cooling process due to thermal stress, cracks, cracks after rolling.
