Types of structures to be protected - buried

The buried works to which cathodic protection can be applied are pipes (gas, oil, water), buried tanks, well linings, lower parts of aerial tanks and sometimes piles or similar elements.

The corrosion of these structures has various origins:

• the local aggressivity of the grounds
• the differential ventilation due to the difference of nature or grain-size distribution of the soils
• the stray currents circulating in the grounds, due sometimes to close cathodic protections.

The pipes are covered by organic coatings, containing asphalt or polymers.

It should be noted that cathodic protection is mandatory for buried pipes transporting petroleum gas or chemical products, as well as for buried tanks with flammable gas or liquefied petroleum gas (LPG).