Mathematical Models for Cathodic Protection of an Underground Pipeline with Coating Holidays: Part 1 — Theoretical Development

CORROSION ◽  
1997 ◽  
Vol 53 (4) ◽  
pp. 264-272 ◽  
Author(s):  
M. E. Orazem ◽  
J. M. Esteban ◽  
K. J. Kennelley ◽  
R. M. Degerstedt
Keyword(s):  
Mathematical Models ◽  
Cathodic Protection ◽  
Theoretical Development ◽  
Underground Pipeline

Evaluation of Stray Current Effect on the Cathodic Protection of Underground Pipeline

1996 ◽  
Author(s):  
K. W. Park ◽  
Y. B. Cho ◽  
K. S. Jeon ◽  
S. M. Lee ◽  
Y. T. Kho
Keyword(s):  
Cathodic Protection ◽  
Drainage System ◽  
High Standard ◽  
Considerable Effect ◽  
Mean Value ◽  
Distribution Analysis ◽  
Underground Pipeline ◽  
Stray Current ◽  
Transit System ◽  
Potential Measurement

Two types of stray current which affect the cathodic protection of underground pipeline are discussed. One is the stray current by DC transit system and the other is that originated from the nearby cathodic protection system. The popular evaluation methods of the pipe-to-siol potential measurement was undertaken to evaluate the corrosion activity of pipeline. In case when the pipe was affected by the stray current, the measured pipe-to soil potential was significantly deviated from the mean value resulting in normal distribution. Analysis of such distribution pattern has revealed that the pipe under investigation was in the condition of insufficient protection (noble mean potential and high asymmetry coefficient) due to the considerable effect of stray current (high standard deviation value). It was also confirmed that the efficiency of drainage system was so low (<10%) due to the improper selection of drainage point. Simultaneous measurement of the magnitude and direction of the sheath current resulted in information about the place where stray current entered into pipe and escaped to soil. For the second case of stray current problem, it is shown that it has been caused by the combined interference from nearby CP system.

Impact of Thin Film Coatings on Cathodic Protection

2002 ◽  
Author(s):  
Daryle Warnke ◽  
W. Brian Holtsbaum
Keyword(s):  
Thin Film ◽  
Cathodic Protection ◽  
Empirical Data ◽  
Large Diameter ◽  
Underground Pipeline ◽  
Film Coatings ◽  
Thin Film Coatings ◽  
Construction Techniques ◽  
Telluric Currents

Thin film coatings, such as fusion bonded epoxy (FBE) coatings have become more popular as an underground pipeline coating especially on large diameter pipelines. This together with improved construction techniques has resulted in very effective coatings. They do however present additional considerations in a cathodic protection design. This paper deals with some issues that one must bear in mind related to cathodic protection when dealing with these superior coatings including a modification to empirical data in cathodic protection pre-designs, an upper polarized potential to prevent cathodic disbondment, inspection in horizontal directionally drilled crossings, an increased effect of telluric currents and an increased possibility of hazardous induced AC potentials. Examples are presented and discussed.

scholarly journals Influence of the soil electrical conductivity in the area of the underground pipeline on energy efficiency of the cathodic protection

2018 ◽  
Vol 245 ◽  
pp. 07015 ◽  
Author(s):  
Vladimir Kiselev ◽  
Alexandr Kalyutik ◽  
Evgenij Rouzich
Keyword(s):  
Electrical Conductivity ◽  
Energy Efficiency ◽  
Cathodic Protection ◽  
Polarization Resistance ◽  
Electrochemical Corrosion ◽  
Underground Pipeline ◽  
Soil Electrical Conductivity ◽  
Underground Pipelines ◽  
Main Factors ◽  
High Dielectric

In this paper we consider main factors which have an influence on energy efficiency of the cathodic protection and analyze them. Cathodic protection is defined as the ratio of the electrical conductivity of electrolyte, which surrounds the underground (underwater) metal construction (pipeline) and its polarization resistance. The obtained results are correct first of all for the case of presence of modern qualitative insulation, which possess high dielectric properties and is made of, for example, polymers or its’ composition and is meant to be used for protection against electrochemical corrosion of the underground pipelines

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