How to prevent rust by astm a179 cold drawn steel pipe

Regarding the three processes of electrochemical corrosion for astm a179 cold drawn steel pipe, the main points of preventing rust are in the following:

First, but for the city gas system, due to underground pipe network intensive, cathodic protection of the external power supply on other cold drawn steel pipe interference, will cause their own benefit, his family affected the situation. And the use of cold drawn steel pipe than the negative metal material and cold drawn steel pipe connected to the sacrificial anode protection law does not appear such a situation, therefore, the city gas transmission pipe should be used anti-rust coating and sacrifice anode combination of anti- Rust method. 


Second, the current buried gas cold drawn steel pipe commonly used outside the rust coating three main PE composite structure, epoxy resin powder (FBE), coal tar enamel, epoxy coal tar pitch and PE tape and other five categories. Three-layer PE composite structure, epoxy resin powder coating performance, and thus Europe and the United States is the main anti-rust coating of cold-drawn steel pipe. In China, from the durability, maintenance costs and other comprehensive economic considerations, the general choice of three layers of PE composite structure rust coating.


Third, in the sacrificial anode protection method, the general use of magnesium alloy as a sacrificial anode protect the cold drawn steel pipe. Due to the destruction of the output current, the design life of the magnesium alloy sacrificial anode is best matched with the useful life of the cold drawn steel pipe, and neither waste nor increase maintenance costs. It should be noted, however, 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 anti-rust methods have different rust quality and cost, should be based on the protection of cold drawn steel pipe under different pressures, different uses and their different environments and different gas delivery, comprehensive and comprehensive consideration of anti-rust method And rust costs. In considering the economic rationality should pay attention to two points: ① gas pipe network construction of a rust-proof investment, ② gas pipe network after the maintenance costs. As the city gas pipeline network is located in the urban areas, put into operation after maintenance and repair costs and higher costs, it should be appropriate to increase investment once in order to reduce the daily maintenance of cold drawn steel pipe maintenance workload.