Diagnosing Internal Current Transfer (ICT) Protecting Infrastructure Correctly
Our Internal Current Transfer investigations uncover hidden corrosion risks caused by improperly isolated or interconnected cathodic systems — especially in upstream oil and gas facilities and pump stations. We help you detect, quantify, and resolve ICT to prolong the life of your pipelines.
Is Your Pipeline System Susceptible to ICT Failures?
Not all cathodic protection systems are equally at risk for Internal Current Transfer. Understanding whether your field setup creates the conditions for unwanted internal current discharge is the first step to proactive prevention. Here’s how to evaluate your system:
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1. Conductive Internal Environment
ICT requires a conductive path inside the pipe for current to travel. Systems are more susceptible if:
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The fluid inside the pipe is conductive, such as produced water, wet gas, or hydrocarbon streams with water dropout.
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Chloride-rich fluids or fluids that support salt bridge formation (e.g., brine-laden water) are present.
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There is internal scale or sediment that can form localized conductive bridges across isolation devices.
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Even seemingly dry systems can be at risk if they intermittently carry conductive fluids or build up condensate, sludge, or deposits over time.
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2. Presence & Type of Cathodic Protection
A pipeline must be electrically continuous with a CP source for ICT to occur. The type of system significantly impacts risk:
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Impressed Current Cathodic Protection (ICCP): High susceptibility due to the driving voltage and current levels that can sustain internal discharge across isolation kits
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Sacrificial Anode CP (SACP):
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Magnesium anodes: Medium susceptibility due to their high driving potential.
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Zinc anodes: Lower susceptibility because of their lower voltage output.
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Systems with long-range bonding, mixed CP types, or unknown isolation performance are often the most vulnerable.
3. Deleterious vs. Non-Deleterious Current Path
Not all current transfer at isolation devices is damaging — but understanding the path it takes is critical.
❌ Deleterious ICT (Electrolytic Path)
Occurs when CP current discharges through the electrolyte, across a fluid medium (e.g., water, salt bridge, or conductive sludge). This type of path results in material loss and internal corrosion.
✅ Non-Deleterious ICT (Electronic Path)
Happens when current flows across a non-corrosive electronic bridge, such as scale build-up or conductive oxides across flange faces. These can bypass the isolation device, but do not cause internal corrosion — although they do compromise the purpose of the isolator.
Your system may not be as “isolated” as it appears — testing is the only way to know.
