Cathodic protection (CP) is an electrical method of preventing corrosion on metallic structures that are in electrolytes such as soil or water. It has had widespread application on underground pipelines, and ever increasing use as the most effective corrosion control method for numerous other underground and underwater structures in oil and gas industries. It is a scientific method that combats corrosion by use of the same laws that cause the corrosion process.

To protect pipelines and other metal structures from corrosion, the oil and gas industry uses CP. The science of CP is based on electrochemistry. It is complex but in short, CP suppresses unwanted corrosion reactions by applying a protective electrical current.

CP provides an effective method of mitigating the corrosion damage to metal surfaces exposed to a conducting (corrosive) electrolyte. This engineering book provides the design requirements for electrochemical protection (CP) of metals against corrosion. The electrochemical methods of preventing corrosion consist of cathodic and anodic protection.

Anodic protection at this stage of development is applicable to limited combinations of metal and corrosive environment so there has been little applications for it in industries so far. Economics and difficulty in application has also limited its application to metal structures. For this reason, the book has emphasized on CP, which had been used widely and effectively in different industries as well as in oil, gas, and petrochemical industries.

Design requirements for CP systems (impressed and galvanic) for buried and immersed metal structures, such as buried pipelines, distribution pipelines, in-plant facilities, vessels and tanks, and marine structures, are described in this engineering book. The book also provides general guidelines for applying cathodic and anodic protection to metal structures.

Also, this engineering book covers the minimum requirements for anodes (high-silicon iron, graphite, magnetite) for use in impressed current CP systems. It specifies the composition, materials, manufacture, properties, inspection, and testing for high-silicon iron, graphite, and magnetite anodes.

Moreover, this book revised survey requirements to ascertain that corrosion control systems installed on buried or submerged structures are properly designed, operated, and effectively maintained. This book also provides information concerning techniques, equipment, measurements, and test methods used in field application. It deals with inspection of coatings in conjunction with CP for its efficiency on current distribution.