Understanding Stray Current
Stray current and the importance of AC mitigation is the study of Electrical influences and mitigation of unwanted electrical current that flows through buried metallic structures such as pipelines, storage tanks, and other infrastructure. If uncontrolled, it can accelerate corrosion, compromise structural integrity, and create safety hazards for workers and the public.
Common sources of stray current include:
- AC powerlines & inductive coupling (shared right-of-way)
- Electrified railways
- DC sources such as competing CP systems or abandoned telephone lines
- Telluric currents (natural electrical currents in the earth)
- Static fault currents (lightning or electrical system faults)
Why Mitigation Matters
Without proper mitigation, stray current can:
- Cause accelerated corrosion on pipelines and assets.
- Compromise safety through touch and step potential hazards.
- Interfere with cathodic protection (CP) systems, reducing their effectiveness.
- Lead to regulatory non-compliance under the PHMSA Mega Rule and other standards that require accurate data collection and proven AC mitigation practices.
By addressing Stray current and the importance of AC mitigation, operators can extend asset lifespan, ensure compliance, and protect personnel and the environment.
The Role of Decouplers in AC Mitigation
One of the most effective tools for AC and stray current mitigation is the use of decoupling devices.
What Decouplers Do:
- Provide a controlled path to ground for AC and fault currents.
- Allow DC isolation to keep cathodic protection systems operating effectively.
- Protect personnel by keeping touch and step potentials within safe limits.
- Maintain system integrity during lightning strikes and surge events.
Key Considerations in Selection
When choosing a decoupler for your project, Cathtect USA recommends evaluating:
- Location and environment (hazardous or non-hazardous areas).
- Expected AC exposure (steady-state vs transient).
- Fault current capacity required.
- Survey compliance – ensuring accurate readings during CIS & DCVG surveys without removing protection.
- Integration options such as built-in isolation switches for safe, easy operation.
Cathtect USA’s Approach
With over 35 years of global CP experience and innovations in solid-state decoupling technology, Cathtect USA provides tailored AC mitigation solutions for pipelines, storage facilities, utility crossings, and industrial systems.
Our innovative SSDs with integrated isolation solve the problem of survey accuracy without sacrificing protection – keeping systems compliant and personnel safe.
Final Thoughts
Stray current and AC interference are inevitable challenges in modern pipeline and industrial environments, but they don’t have to threaten your assets. With the right mitigation strategy and properly specified decouplers, operators can achieve:
✅ Safer working environments
✅ Reliable cathodic protection performance
✅ Regulatory compliance
✅ Extended asset life and reduced costs
At Cathtect USA, we specialize in helping you choose the right device, with the right specifications, for the right application.
📞 Contact us at (772) 646-2873 or visit www.cathtectusa.com to learn more today.
