For the three electrochemical corrosion processes of ASTM A179 cold drawn steel pipe, the main points of rust prevention are as follows:


First of all, but for the city gas system, due to the dense underground pipe network, the cathodic protection of external power supply to other cold drawn steel pipe interference will cause its own interests, affecting his family situation. The use of cold drawn steel pipe is not the case with the sacrificial anode protection method using a negative metal material and a cold drawn steel pipe. Therefore, the city gas gas pipeline should adopt an anticorrosive agent combined with a rustproof coating and a sacrificial anode. t method.


Secondly, there are three kinds of PE composite structures, such as epoxy resin powder (FBE), coal tar enamel, epoxy coal tar pitch and PE tape, which are commonly used in buried cold-drawn steel pipe. The three-layer PE composite structure and epoxy resin powder coating have excellent performance, so Europe and America are the main anti-rust coatings for cold drawn steel pipes. In China, from the perspective of comprehensive economic considerations such as durability and maintenance costs, three-layer PE composite structure anti-rust coating is generally used.


In the sacrificial anode protection method, a magnesium alloy is generally used as a sacrificial anode to protect a cold drawn steel pipe. Due to the destruction of the output current, the design life of the magnesium alloy sacrificial anode is preferably matched with the service life of the cold drawn steel pipe, neither wasting nor increasing the maintenance cost. However, it should be noted that sacrificial anode protection should not be used when the soil resistivity is too high and the protected cold drawn steel pipe passes through the water.


Fourth, different rust prevention methods have different rust prevention quality and cost. The rust prevention method should be comprehensively considered according to the protection of cold drawn steel pipes under different pressures, different uses, different environments and different gas transmission modes. OD and rust costs. When considering economic rationality, it should pay attention to two points: 1 an anti-rust investment in the construction of gas pipeline network; 2 the cost after maintenance of gas pipeline network. Since the city gas pipeline network is located in an urban area, the maintenance cost is high, and after the operation, the cost is high, and it is necessary to increase the investment to reduce the daily maintenance workload of the cold drawn steel pipe.