Cathodic protection ppt

Cathodic protection (CP) is a method of corrosion control that can be applied to buried and submerged metallic structures. It is normally used in conjunction with coatings and can be considered as a secondary corrosion control technique. Holidays are a major cause for corrosion failure.

However, his role in the applica-tion of cathodic protection should not be ignored. The cathodic protection anodes are installed to become the anode in this larger corrosion cell and provide the location for all oxidation reactions in the cell. PPT Group of Companies undertakes Design and Construction Projects for new Pipelines.

The CP cost could be 5-times, if it is installed after completion of project as it involves lot of excavation and restoration of structures. CATHODIC PROTECTION for STEEL PILES - authorSTREAM Presentation. ELECTROCHEMICAL REACTION : ELECTROCHEMICAL REACTION When Two Metals are Electrically Connected with each other, in an electrolyte (e.g. Sea water, Soils, etc.), electrons flow from more active metal to least active, due to the difference in electric potential. Protective film is formed on the surface of metal structure which decrease the.

Cathodic Protection can be installed at the time of erection of the plant at a very low cost. On an unprotected pipeline, there are naturally occurring potential variations. Wherever you go from a minor positive to a minor negative, there is a current flow where galvanic corrosion will occur.

Physical dimensions of structure to be protected.

To learn more, read Galvanization and its Efficacy in Corrosion Prevention. The method is now well established. Always compare alternatives of sacraficial or impressed current corrosion as they will vary with tank size and water quality.

Lary Corrpro Companies, inc. The two most common applications of CP are for buried pipeline systems and vessels as well as offshore platforms. CP is not used to protect equipment in atmospheric conditions or protect components. New cathodic protection (CP) criteria were developed based on AC and DC current densities measured using coupons. Using these criteria, the design of CP systems for newly constructed pipelines, paralleling high voltage AC power lines, and DC rail transit systems, was successfully performed.

Just as cathodic protection designs for new construction are made to facilitate installation of the asset, the cathodic protection design criteria for retrofit projects are designed to essentially to polarize a structure from native state potential and to provide adequate redundancy in design to allow for some system damage during installation. PowerPoint Presentation Last. All cathodic protection removable links inside the accessible equipment shall be left open and no impressed current stations shall be energized without COMPANY’s approval. The second is to apply cathodic protection to complex structures, an expedient which shifts the mixed potential of the couple below the open-circuit value of the more electronegative material.

Item (b) of figure illustrates the cathodic polarization curves of the two coupled metals when cathodic protection is present. The anode of this circuit may consist of an element, such as zinc, magnesium or aluminum, which is more “active” in the electrochemical series than is the structure to be. Maintaining the ageing infrastructure such as underground pipelines is a challenge to facility owners worldwide.

Understanding why and how cathodic protection works or fails can help the operator formulate appropriate strategy in managing the pipeline corrosion problems. Some UST systems require a cathodic protection (CP) system.