Details of anti-corrosion processing of national standard spiral steel pipes: In the three electrochemical corrosion processes for buried pipelines, the anti-corrosion method of national standard spiral steel pipes is to suppress one of the processes first. For example, adding anti-corrosion coating to the outer wall of the steel pipe can increase the circuit resistance and reduce the corrosion current; add a DC power supply to make the anti-corrosion national standard spiral steel pipe cause a negative potential to the soil and form cathodic protection, which can eliminate the potential difference between the cathode and anode, from the Fundamentally stop the cathodic process.

National standard spiral steel pipe anti-corrosion

    At present, anti-corrosion coatings can cure the surface, and the method of cathodic protection can cure the root cause. However, if the anti-corrosion coating of the steel pipe is damaged, the partial exposed iron part will accelerate the corrosion. Therefore, the combination of anti-corrosion coating and cathodic protection can cure both the root and the root, and is economical and effective. At present, the United States and other countries have clearly stipulated that the steel pipe must use cathodic protection while using anti-corrosion coating.

    However, due to the dense underground pipe network, the urban gas system is not suitable for the combination of anti-corrosion coating and cathodic protection. The main pipe should adopt the anti-corrosion method combining anti-corrosion coating and sacrificial anode. For other non-main pipelines with lower pressure, the anti-corrosion coating method is generally used directly.

    At present, the commonly used external anti-corrosion coatings for buried gas pipelines mainly include: three-layer PE composite structure, epoxy resin powder, coal tar enamel, epoxy coal tar, and PE tape. Among them, the three-layer PE composite structure and epoxy resin powder anti-corrosion coating have excellent performance. In my country, considering the comprehensive economic factors such as the service life of anti-corrosion steel pipes and maintenance costs, the three-layer PE composite structure anti-corrosion coating is the first choice.

    Since different anti-corrosion methods have different quality and cost, they should be comprehensively considered according to their different pressures, different uses, different environments, and different gas transportation. However, when considering, we should pay attention to the one-time anti-corrosion investment in the construction of the gas pipeline network; and the maintenance cost after the operation of the gas pipeline network.