Why are 3PE anti-corrosion pipes effective in preventing corrosion?

3PE coated steel pipes, as the name suggests, are steel pipelines with three layers of corrosion-resistant PE coating. This type of 3PE coated steel pipe is widely used for its excellent corrosion resistance. What are the corrosion-resistant materials that make up the structure of 3PE coated steel pipes? What are the principles behind their corrosion prevention capabilities?

Pipe corrosion prevention typically employs two primary methods: external coating and the application of cathodic protection.

2. Although the vast majority of the pipeline's surface is coated, even minor leaks can lead to unimaginable corrosion rates, sometimes even perforation or cracking. Therefore, in pipeline corrosion prevention, it is common to pair the coating system with cathodic protection to achieve complete coverage, preventing unimaginable consequences in the future.

3. Cathodic protection for pipeline corrosion prevention is divided into sacrificial anode protection and impressed current cathodic protection.

The purpose of using a coating in the anti-corrosion of 3PE pipeline is to form a continuous layer of insulating material, which directly insulates the metal from the electrolyte it comes into contact with, preventing the occurrence of proper electrolytic reactions.

5. Discontinuities in the coating application process are referred to as leak points, primarily caused by issues during application, transportation, or installation. They may also be due to aging soil stress on the coating or the movement of pipes within the soil. Failure to timely detect and address these issues can lead to damage caused by third parties.

6. Principle of Cathodic Protection with External Current: By applying an amplitude current to the protected metal, corrosion on the structure stops when all cathode points are polarized to the open-circuit potential of the active anode point.

7. Composition of Impressed Current Cathodic Protection: Rectifiers and Constant Potential Meters

8. Rectifier: Converts alternating current (AC) to direct current (DC).

9.3 3PE Coated Steel Pipe > Potentiostat: An electronic instrument capable of automatically controlling the pipeline potential to remain constant.