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Impressed Current Cathodic Protection Auxiliary Anode

Composition of Deep Well Anode
The cathodic protection potential distribution is uniform along the dimensions of the protected object;
Minimal interference with other installations.
Cables with lightning protection measures use galvanized steel wire reinforcement without an additional protective layer outside the plastic sheath, which improves the leakage load of the cable jacket. This reinforcement is typically a 2mm thick flat steel strip, which is particularly susceptible to corrosion in soil. To ensure lightning protection functionality throughout the cable's effective lifespan, cathodic protection should be applied to the reinforced steel strip.
Flexible anodes are widely used in the United States for protecting petroleum metal facilities, underground metal piping and structures in power plants, and ship docks. Even the American Water Works Association (AWWA) has followed the recommendations of the National Association of Corrosion Engineers (NACE) and extensively adopted flexible anodes for protecting urban water supply networks. In 1999, a delegation from China National Petroleum Corporation (CNPC) visited Europe to study pipeline construction and found that many European pipelines, such as Zeepipe, Asgard, Europipe1, Europipe, and Norfra, also widely used flexible anode technology for cathodic protection.
In the regional cathodic protection project for the Siberian Pacific Pipeline station area, undertaken by the Pipeline Bureau and designed by Russians, flexible anodes were also used. Beijing

The Pipeline Project Department forwarded a design document for the pipeline section within Russian territory. The Russians still employed flexible anode protection for this pipeline. EU standards also recommend the use of flexible anodes for regional cathodic protection.
Figure 1 compares the characteristics of flexible anodes with traditional deep well anodes and distributed shallow buried anodes. The red, black, and white curves in Figure 1 represent the potential distribution patterns of flexible anodes, distributed anodes, and deep well anodes, respectively, on the pipeline. The potential distribution for flexible anodes is -0.9 to -1.0V; for distributed anodes, it is -0.79 to -1.3V; and for deep well anodes, it is -0.7V to -1.6V. It is evident that the potential distribution of flexible anodes is the most balanced, effectively avoiding issues of under-protection and over-protection. Over-protection poses significant risks to the pipeline's anti-corrosion coating and material, especially for X80 steel, and cannot be overlooked.
From the above table, it can be seen that the protection parameters of flexible anode regional cathodic protection are ideal, with no issues of under-protection or over-protection. There is also no stray current interference with the main pipeline.

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