Factors to be considered in the implementation of cathodic protection

The factors causing the uneven distribution of cathodic protection potential on structures are as follows:

① The distance between the anode and the protected object is too small;

② The resistivity of environmental medium is high;

③ The protective current required by the protected structure is large;

④ High resistance exists between different components of the protected structure;

⑤ The quality of anticorrosive coating on the surface of protected structure is uneven.

These factors may interact with each other. In general, the surface of the structure closest to the auxiliary anode receives the maximum cathodic protection current density and the corresponding protection potential is the most negative. This may lead to over negative protection potential at the site, which may lead to harmful over protection; or the protection current density of other parts is not enough and the protection potential is insufficient, which are all undesirable results.

In addition, it is uneconomical for some parts of the protected structure surface to receive excessive and unnecessary current, which will significantly increase the operation cost. One of the improvement measures is to add DC power supply and reconfigure auxiliary anode.

The economy of cathodic protection must be fully considered in order to implement cathodic protection successfully. It is necessary to consider not only the initial cost of the cathodic protection system, but also the maintenance cost of the long-term operation of the cathodic protection system.

The factors that affect the initial cost of cathodic protection are: the electrical continuity of the structure, the quality of the anticorrosive coating, the resistivity of the environmental medium, the possible DC interference on adjacent structures after the implementation of cathodic protection, and other side effects. The factors that affect the daily operation cost are as follows: for impressed current cathodic protection, it is mainly for daily power consumption; for sacrificial anode cathodic protection, it is mainly anode life and anode replacement frequency.

Shandong Linyi Bosi conductive materials Co., Ltd. is a high-tech enterprise specializing in the production of MMO flexible anode, conductive polymer flexible anode and titanium coated anode, mainly providing cathodic protection technology, engineering design, installation and technical services.