Cathodic Protection Of Pipelines Research Articles

Cathodic protection of pipelines:

ONE OF the nightmares for the corrosion engineer applying cathodic protection to a jointed pipeline is the problem of the missed coupling, or severed coupling. For cathodic protection purposes the cathode has to be electrically continuous, which means that some types of mechanical joints which rely on joints for sealing which are electrically non‐conductive have to be made electrically continuous. This is done by means of a bond strap. The attachment can be by either:—

Cathodic protection of pipelines : a deep hole groundbed

There are three reasons for installing a deep hole groundbed by which it is meant inserting power impressed anodes at a depth greater than 50 ft. The three reasons are:— 1. To minimise interference problems. 2. To circumvent the problem of high surface soil resistivities. 3. To overcome wayleave difficulties. This account is concerned with 1 above.

Cathodic protection of pipelines: is the standard potential too low?

One of the fundamentals of cathodic protection is that a steel structure immersed in an electrolite is protected from corrosion if its potential with reference to a copper cell is −0.85 V or less (in the negative sense). Another fundamental of cathodic protection is that, to obtain correct results, the reference cell should be as close to the cathode as possible. For pipeline corrosion surveys and maintenance this condition means that the cell will be placed over the pipeline, the distance from the cell to the pipeline then depending on the pipe depth. The question is therefore raised: is −0.85 V the correct protection value when the reference cell is on the surface over the pipeline but perhaps 3 ft away from it?

海底管の電気防食に関する二三の考察 (その2)

海底管の電気防食に関する二三の考察 (その2)

Solution Potentials and their Interpretation in PIPELINE CATHODIC PROTECTION—PART 1

In order to understand thoroughly the subject of pipeline cathodic protection it is essential to comprehend fully the significance of solution potentials. In this article, reproduced by courtesy of the Pipeline Engineer (Dallas, Texas, U.S.A.), the author does this in considerable detail.

海底管の電気防食に関する二三の考察 (その1)

海底管の電気防食に関する二三の考察 (その1)

CATHODIC PROTECTION.

A short history of cathodic protection, from the discovery of its operating principle about 1800 and its use by Sir Humphry Davy a few years later, is followed by a description of where and how corrosion of metal occurs, the use of wrapping and of a sand bed around a pipeline, cathodic protection of pipelines, and of steel-piled jetties, appropriate levels of impressed current, and the prevention of sparking between a berthing ship and a cathodically protected petroleum jetty. Periodic verification of the effectiveness of both impressed-current and sacrificial-anode systems of cathodic protection is necessary, and worn-out anodes have to be replaced. The Author describes the half-cells of copper/ copper sulphate and silver/silver chloride which are used for testing protection systems in soil and sea water respectively, and states appropriate voltage levels for each. The Paper also describes a typical cathodic protection installation with impressed current.

高比抵抗土壤中の管路のマグネシウム陰極防食

高比抵抗土壤中の管路のマグネシウム陰極防食

Use of Magnesium for Cathodic Protection Of Pipe Lines in High Resistivity Soil

Abstract A cathodic protection installation is described in which satisfactory protective potentials were attained on approximately 400 miles of enamel coated pipeline with a total current between ...

PIPELINE PROTECTION IN THE MIDDLE EAST — PART 2: Preparing the Ground and Checking the Results

After dealing in Part 1 with the actual corrosion of pipelines under the varied atmospheric and ground conditions in the Middle East, Mr. Sparrow deals with practical problems in the construction of groundbeds in the desert, their siting, and the siting of terminals and tank farms. Stress is laid on the importance of regular and thorough checking of pipeline protection methods, both pipe wrapping and cathodic protection.

第7巻正誤表

第7巻正誤表

Current Requirements for Cathodic Protection of Pipe Lines★

Abstract The problem faced by the engineer seeking to cathodically protect a buried pipe line is to find the best and most economical way to drain from certain selected points on the line sufficient current to give adequate protection. Three basic methods to this end are placing the line under full protection, placing the line under partial protection and calculating the requirements for complete protection, both using, temporary installations; and measuring the electrical characteristics of the line and calculating its behavior under various proposed systems. The fourth method—an empirical estimate—is more important than its nature would indicate because certain assumptions based on observation and experience usually are helpful in arriving at a final conclusion. Principal problems also faced by the engineer are those of securing electrical continuity where joints other than welded are used and insulating the line from other buried structures. The author recommends a procedure involving steps such as: Determining static potentials, draining interrupted current from selected points and from data thus collected determining the relationship between polarization and driving voltage and attenuation of driving voltage; computing desired effect of combinations of drainage currents. Also discussed are such questions as technique for making potential readings, various means of plotting data for best use, what constitutes “adequate” protection, where the electrode should be placed in making potential readings and other matters.

Cathodic Protection and High Resistivity Soil

Abstract A two-part report of Southeastern Pipe Line's cathodic protection system; Part One deals with a 25-rectifier system from Port St. Joe, Florida to Atlanta, Georgia, which lowers the pipe-to...

Corrosion and Cathodic Protection of Pipelines

Journal AWWAVolume 44, Issue 5 p. 413-426 Article Corrosion and Cathodic Protection of Pipelines W. R. Schneider, W. R. SchneiderSearch for more papers by this author W. R. Schneider, W. R. SchneiderSearch for more papers by this author First published: 01 May 1952 https://doi.org/10.1002/j.1551-8833.1952.tb15379.xCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume44, Issue5May 1952Pages 413-426 RelatedInformation

The Corrosion Products on Zinc Anodes Used Underground

The presence of sulfates, such as gypsum, in the soil around zinc anodes used in the cathodic protection of pipelines has been observed to largely prevent the loss of current flow normally found after a time in ordinary soils. The present examination of the corrosion products on two anodes used in gypsum-bearing soil gave an opportunity to determine the mechanism by which sulfates affect the film resistance. It was found that the product adjacent to the zinc was a porous, needle or plate-like mass of crystals of basic zinc sulfate while the outerlayers were a dense, white mixture of the basic sulfate and basic carbonate. The permeability of the basic zinc sulfate layer probably accounts for its superior electrical conductivity. An hypothesis for the mechanism by which the two layers are formed is suggested in the paper.

Construction and Ratings of Copper-Oxide Rectifiers for Cathodic Protection of Pipelines

Construction and Ratings of Copper-Oxide Rectifiers for Cathodic Protection of Pipelines

Cathodic protection of pipe lines

Cathodic protection of pipe lines