Experts answer questions on epoxy anticorrosion technology of buried steel pipe

With the construction of key projects such as the west to east gas transmission project and the construction of a large number of urban underground pipe networks, the problem of pipeline anti-corrosion has become prominent, especially the epoxy material, which is an important and excellent anti-corrosion product, has attracted more and more attention Recently, China epoxy Industry Association ( often received a rescue call For this reason, experts of the association specially met with online reporters of China epoxy industry to answer questions publicly According to the expert, anticorrosion is a very professional subject, which must be analyzed according to the specific conditions of environment, climate, medium and pipeline materials But generally speaking, the national standards have a very good expression For example, the technical standard for polyethylene anticorrosive coating of buried steel pipeline (SY / T 4013-1995, approved by the State Bureau of quality and technical supervision on December 18, 1999) According to the standard, extruded polyethylene anticorrosive coating is divided into two-layer structure and three-layer structure The bottom layer of the two-layer structure is adhesive and the outer layer is polyethylene; the bottom layer of the three-layer structure is epoxy paint, the middle layer is adhesive and the surface layer is polyethylene The epoxy coating in the three-layer structure can be liquid epoxy coating or epoxy powder coating As for epoxy coating, the standard stipulates that when liquid epoxy coating is used as three-layer structure bottom layer, solvent-free epoxy coating must be used After selecting the coating, the applicability test shall be carried out, and the coating can be used only after meeting the requirements When the three-layer structure anticorrosive coating is applied with epoxy coating, the epoxy coating shall be evenly applied on the steel pipe surface When the epoxy powder coating is used for the bottom layer, the coating must be carried out in the process of epoxy powder gelation; when the liquid epoxy coating is used for the bottom layer, the coating shall be carried out before the final setting of the epoxy coating When the epoxy powder coating is used as the bottom layer of the three-layer structure anticorrosive coating, the interval between the application of epoxy powder and the cooling of the anticorrosive coating shall ensure that the fusion bonded epoxy powder coating is fully cured In addition, the following materials shall be provided when selling anticorrosive pipes: factory certificate and quality inspection report, factory certificate and inspection report of joint coating and elbow anticorrosive materials, joint coating and elbow anticorrosive construction record and inspection report, joint coating record and inspection report, and other relevant materials required by the construction unit.