Cathodic protection of pipelines from stray currents

DC stray current can cause severe corrosion on buried pipelines. For this reason a reliable protection of pipelines from stray currents should be provided. In the present paper a scheme of the cathodic protection is considered. Different types of corrosion protection (drainage and cathodic) are mentioned and presented as a block diagram giving the relationship between them. The two types of automatic control (analog and digitally) are also noted there. First one (electromagnetic and electromechanical) can be realized in two ways - either by relay or by transformer. The paper finish with conclusion remarks about the importance of the considered cathodic protection.