Application fields of hot-dip galvanized steel pipes: widely used in domestic water transportation, fire fighting, gas, telecommunications, electricity, air conditioning, pipes for supporting structures and sewage transportation and industrial water supply projects, seamless steel pipes used in high-pressure water mist fire fighting and high-pressure gas fire fighting, super-high-rise fire fighting systems and high-pressure pipeline systems. How to judge the quality of hot-dip galvanized steel pipe: judging from the smoothness of the inner and outer walls of the pipe, the purity of zinc for production, the uniformity of galvanized layer, the burr height, straightness, wall thickness, roundness and length of weld. The enterprise was established on January 10th, 1999, located at No.21, Zhenxing Street, Lijiao, Haizhu District, Guangzhou. The enterprise covers an area of about 21,500 square meters, with a workshop building area of about 5,200 square meters. It has a longitudinal shearing production line, a high-frequency welded pipe production line, a hot galvanizing line and its ancillary equipment.