Current and potential distribution on a coated pipeline with holidays. Part 2 - Comparison of the effects of discrete and distributed holidays

Journal Article · Mon Mar 01 04:00:00 EST 1993 · Corrosion (Houston); (United States)

DOI:https://doi.org/10.5006/1.3316042· OSTI ID:6456212

Orazem, M E ^[1]; Kennelley, K J; Bone, L ^[2]

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1. Univ. of Florida, Gainesville (United States)
2. ARCO Oil and Gas Co., Plano, TX (United States)

The current and potential distribution on a pipe must be considered if cathodic corrosion protection will be provided with anodes placed in close proximity to the pipe. Correct design of a cathodic protection (CP) system will depend strongly on the types of holidays assumed to exist in pipe coating. Two models for the influence of holidays in coated pipes that encompass the extremes of holiday distribution are compared. The performance predicted by these models is compared to the experiment. The design constraints for a pipe with a single coating holiday are much more severe than those for a pipe with a uniform coating efficiency reduced in proportion to the holiday area. Therefore, the CP design must account for discrete holidays if localized damage to the coating is anticipated. An approach to CP design is suggested where a relationship will be established between the percentage of pipe that is expected to be bare and the effective' coating efficiency that can be used to design the CP system.

• OSTI ID: 6456212
• Journal Information: Corrosion (Houston); (United States), Journal Name: Corrosion (Houston); (United States) Vol. 49:3; ISSN 0010-9312; ISSN CORRAK
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
022000 -- Petroleum-- Transport
Handling
& Storage
42 ENGINEERING
420205* -- Engineering-- Transport & Storage Facilities-- (1980-)
CATHODIC PROTECTION
COATINGS
COMPARATIVE EVALUATIONS
CORROSION PROTECTION
CURRENTS
DEFECTS
DESIGN
DISTRIBUTION
ELECTRIC CURRENTS
ELECTRIC POTENTIAL
EPOXIDES
EQUIPMENT PROTECTION DEVICES
EVALUATION
MATHEMATICAL MODELS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PERFORMANCE
PIPELINES
PROTECTIVE COATINGS
TWO-DIMENSIONAL CALCULATIONS
UNDERGROUND FACILITIES