Deep anodes pipeline protection

The first anode installation for the cathodic protection of gas pipelines in New Orleans consisted of a 5-m-long horizontal cast-iron tube. Later old tramway lines were used. Since in downtown New Orleans there was no suitable place to install impressed current anodes and to avoid detrimental effects on other pipelines, Kuhn recommended the use of deep anodes which were first installed in 1952 at a depth... 

Galvanic Anode Cathodic Protection of Internal Submerged Surfaces of Steel Water Storage Tanks Metallurgical and Inspection Requirements for Offshore Pipeline Bracelet Anodes Design, Installation, Operation and Maintenance of Impressed Current Deep Groundbeds Internal Cathodic Protection Systems in Oil-Treating Vessels... 

Metal anodes using platinum and precious metal oxide coatings are also incorporated into a variety of designs of impressed current protection for pipeline and deep weU appHcations, as weU as for protection of condenser water boxes in power generating stations (see Pipelines Power generation). 

Electrochemical protection is divided into cathodic and anodic protection. Cathodic protection based on the change of potential of a metal in the negative direction is realized in electrolytic environments, in most cases neutral, mainly of steel and reinforced concrete structures. A well-designed and correctly realized CP reduces the corrosion rate to almost zero. In practice it is realized with the use of an impressed current or protectors (galvanic anodes). The scope of application is enormous and continuously increases. With the use of this technology it is possible to protect vessels and ships, docks, berths, pipelines, deep wells, tanks, chemical apparatus, underground and underwater municipal and industrial infrastructure, reinforced concrete... 

A common cathodic protection design is the use of bracelet anodes that originally were zinc but now, with improved alloys, are usually aluminum. Alternately, high-silicon cast iron anodes mounted on sleds, buried in the sea bed 250 feet from a given pipeline and midway between shore and the spar buoy ship connection have performed well. Anode return cables can be a maintenance problem unless properly secured to the pipelines and buried at least 5 feet into the sea bed, between the pipelines and the anode sled. Anode beds can also be installed in the beach itself, but they must be deep enough to be in the saltwater intrusion area. 

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