Telluric Effect

Cathodic Protection Numeric Simulation

Cathodic protection monitoring is a most common practice for the assessment of effectiveness of corrosion protection.  However, metal loss due to corrosion is somehow evident even on pipes are deemed to be well protected based on standard monitoring and survey techniques.  The effectiveness of the the field survey techniques are further questioned for the structures within the common corridor with multiple functioning cathodic protection systems in place. Numeric simulation provides better opportunity to understand the pipe potential as current density along the structure. This, along with standard survey practice, renders a clear picture of the effectiveness of the cathodic protection….
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DC STRAY CURRENT ANALYSIS AND MITIGATION

Introduction DC stray current is defined as current flowing through the path other than the intended. The DC stray current could be either natural sources, e.g. telluric, metallic mineral deposit, or artificial sources, e.g. foreign pipeline, HVDC transmission line, DC tram, etc. DC stray current is a big threat in pipeline integrity. The severity of the risk is a related to the soil resistivity: the lower the soil resistivity, the more likely to form such electrical conductance path, i.e. stray current related corrosion. The root cause of sewer explosion in 1992 Guadalajara Mexico is stray current corrosion of ductile iron pipe….
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