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Diploma in Cathodic Protection Engineering

Understand the principles of cathodic protection in the prevention and control of corrosion in this free online course.

Publisher: NPTEL
Corrosion of engineering structures is inevitable and as a result, it causes several issues that affect the economy, the ecosystem and the safety of humans. This free online course deals with the external corrosion of buried and submerged engineering structures and how to control or prevent corrosion by employing cathodic protection. By completing this course, you will learn a lot about corrosion and the basic principles of cathodic protection.
Diploma in Cathodic Protection Engineering
  • Duration

    10-15 Hours
  • Students

  • Accreditation






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Engineering structures like pipelines, storage tanks, ship hulls, offshore structure, etc. are among the major infrastructures across the globe which are affected by widespread corrosion. Cathodic protection is a method for preventing corrosion on these engineering structures. This course is designed to give you the details of cathodic protection and explain corrosion control and preventive measures. You will start this course by learning about corrosion, the forms of corrosion, corrosion control measures, as well as the chemical reactions that cause corrosion. You will study the types of corrosion that affect the external engineering body structures.  The role of soil on corrosion, microbes, and metal surfaces, and how they affect the external corrosion of pipelines will be highlighted. Then, the basic principles of cathodic protection will be considered. You will also learn the differences between chemical and electrochemical reactions in corrosion. The Evans diagram will be used to verify the relationship between potential and current in the electrochemical corrosion process of metals in this section. Understanding the basics of cathodic protection criteria is as important as understanding its implication on corrosion, hence the various types of criteria available for cathodic protection and their merits and limitations will be explained.

The pipelines applicable to engineering structures in a typical plant and buried structures undergo a lot of changes over time. In this section of the course, you will learn the concepts involved in assessing pipelines experiencing corrosion through surveys. This will be taught in two parts. The first part consists of natural surveys that apply to buried pipelines, the soil resistivity survey, and the pipe-to-soil potentials survey. The second part will deal with the line current and the drain current measurements surveys. You will also be shown the list of information that is required to survey a pipeline with or without cathodic protection. The American Water Works Association rating system for soil corrosivity will be highlighted. Then, you will study the importance of anode ground bed as well as the equations governing the resistivity of the anode ground beds. Also, specific aspects of cathodic protection concerning storage tanks, offshore structures, and ship hulls will be discussed. The cathodic protection of tanks, tank bottoms, heat exchangers (Cooling water systems), and offshore structures which involve pipelines and floating structures will be emphasized.

Moreover, it is important to understand how anodes perform in order to have a better anode for the cathodic protection of structures. In this section, you will study the functions and requirements of anodes and the role of polarization of the ground bed anodes. Then, you will be taught some equations that will enable you to better understand the concepts of cathodic protection. This will be illustrated using four worked-out examples. Thereafter, the sources of stray current corrosion, and how to detect and mitigate them in buried engineering structures will be discussed.  You will also learn why a protective coating is required when the pipeline and other structures are cathodically protected. The requirements of these coatings and their types appropriate to engineering pipelines will be outlined. Furthermore, the methodology of controlling corrosion of internal oil and gas pipelines which is entirely different from other pipelines will be considered. Towards the end of the course, the basic principles of anodic protection and how they can be applied in the field will be examined. The differences between anodic protection and cathodic protection will also be evaluated. This course is challenging and technical but anyone studying cathodic protection, or related fields will find it exciting and fulfilling. Are you up for the challenge? Start this free online course today.

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