Galvanized steel pipe common defects like these: 

1, galvanized zinc tablets appearing on the surface, that is, those rough small particles are not polished, which is more than affect the appearance of small particles, but also affect the use. The reason for this is because the particles of slag galvanizing bottom too agitated by the machine float, adhere galvanized sheet surface, the temperature is too high there is because the production of bottom ash float making, in addition, zinc solution aluminized too, that aluminum and zinc have a good affinity, thus together, attached to the galvanized sheet surface. Elimination of zinc tablets need only remedy can handle, for example, often deal with bottom ash, keep cleaning degree galvanized steel price environment; galvanized liquid temperature is not too high, kept at 440 ℃ ~ 450 ℃ appropriate. Liquid zinc aluminum content is not too high, remained at about 0.1% is appropriate, Also note that inventory for too long will increase the oxidation, etc. In short, as long as strict production of zinc tablets, or can be eliminated. 

2, galvanized surface to form a thick edge, which means that the edge than in the middle portion of a thick layer of zinc, it becomes a thick edge defects, is not conducive to strip coiling. Thick edge is divided into high-speed and low-speed thick edge thick edge to form a thick edge of the reasons is because the price of gas galvanized steel knife angle adjustment caused by poor air blowing, arising form the spoiler to appropriately adjust the intensity of the air knife this defect can be excluded. 

3, if clogged air knife gap will form an air knife marks, require a special cleaning tools to clean up. 

4, gray galvanized layer, which is due to mixed with iron and zinc alloy caused. 

In addition, there are some surface defects, such as air knife scratches, zinc projections, conchoidal surface, rib defects, etc., which requires all galvanized steel prices manufacturers in the production process in strict operating procedures, strict process to produce better quality products.