| Résumé : |
Protective coatings for carbon steel are well known as an economical method of controlling corrosion versus the use of alternative materials such as stainless steel. At first glance, buried piping seems to have a stable environment. One might assume that coatings would not necessarily be required, as they might be for atmospheric environments, which are bombarded with rain, snow (depending on location), fog, ultraviolet light and significant temperature differentials. Buried environments, however, even in semi-arid climates, contain enough moisture in the soil to conduct ionic current, which completes the circuit for corrosion of most metals.
One way to control buried corrosion is to employ cathodic protection (CP), and indeed, buried pipe corrosion can be controlled with CP alone. The limitation of using solely CP, however, is the amount of CP required to protect the exposed surface area. The greater the current requirements, the larger and more expansive the CP required, meaning greater installation, maintenance and monitoring costs which drives up the cost of operating a pipeline. And for pipelines carrying hazardous materials, the requirements for maintaining the lines are prescribed by federal law. Therefore, a cost-effective design approach is to use coatings in conjunction with cathodic protection to protect the line. |
Aller sur edunet
Accueil
Fundamentals of fusion-bonded epoxy application in JOURNAL OF PROTECTIVE COATINGS & LININGS (JPCL), Vol. 35, N° 4 (04/2018)
