Authors: Charles Venditti | janvier 15, 2025

The increasing presence of HVAC/DC transmission lines in modern power infrastructure has raised concerns about their impact on pipeline integrity. These systems, often co-located within shared corridors, generate electromagnetic fields (EMF) that introduce significant risks such as accelerated corrosion, equipment failures and safety hazards. Addressing HVAC/DC interference is now essential for ensuring long-term pipeline reliability and personnel safety.

HVAC/DC Interference and Its Impact on Pipelines

As energy infrastructure becomes more complex, including the addition of renewable energy projects like solar farms and battery energy storage systems (BESS), HVAC/DC interference management has become increasingly important. Right-of-way (ROW) management plays a pivotal role in assessing and mitigating interference within shared corridors, ensuring the safe operation of pipelines adjacent to power transmission systems 

Right-of-Way (ROW) Interference

ROW programs based on electromagnetic field theory, are critical tools for evaluating interference in long-distance, multi-circuit pipelines. For instance, modeling a 116-mile pipeline corridor where gas pipelines and power lines coexist helps assess the potential risks posed by EMF exposure and ensures operational safety​.

Mechanisms of Interference

High-voltage power lines generate EMFs that induce voltages in adjacent pipelines, which can compromise their structural integrity. Modeling both steady-state and fault conditions, along with lightning scenarios, provides comprehensive insight into the interference mechanisms that could affect pipeline performance​.

Modeling for Pipelines

Specialized tools can enable precise modeling of the interactions between pipelines and nearby power circuits. These models focus on key safety and corrosion risks, including Touch Voltage, Step Voltage, AC Corrosion Current Density, and Coating Breakdown Voltage. Additionally, Arc Distance modeling is essential for assessing potential damage from lightning induced arcing​.

Electromagnetic Fields (EMF) Analysis for Pipeline Integrity

EMF generated by HVAC/DC systems interacts with pipelines, potentially causing operational disruptions and posing risks to personnel. Compliance with IEEE and AMPP standards is essential to ensure that EMF exposure remains within safe limits for both the pipelines and adjacent infrastructure​.

Equipment Integrity and Corrosion

EMF interference can significantly degrade equipment over time. For instance, Arc Distance—the distance over which an arc can form—demonstrates the potential damage caused by high EMF exposure. Accurate analysis of AC/DC corrosion risk is vital for preventing long-term pipeline failures​.

Regulatory and Safety Standards

Compliance with EMF exposure guidelines, such as those from IEEE, IEC and AMPP, is critical for ensuring the safety of pipelines in shared corridors. Field studies and continuous monitoring are necessary to meet these standards and to prevent interference from HVAC/DC systems from jeopardizing pipeline operations​.

Pipeline Integrity Risks from HVAC/DC Interference 

Corrosion Acceleration

HVAC/DC interference can lead to accelerated corrosion at vulnerable points along the pipeline, especially where protective coatings have broken down. Monitoring AC current density and assessing coating breakdown voltage are key strategies for mitigating these risks​.

Impact on Cathodic Protection Systems

HVAC/DC interference can disrupt cathodic protection (CP) systems, which are designed to prevent corrosion. Careful balancing of CP systems under EMF exposure is required to ensure their effectiveness, especially in high voltage environments​.

Personnel and Equipment Safety

High Touch and Step Voltage levels pose serious hazards to workers near interfered pipelines. Additionally, arc-induced damage to monitoring equipment underscores the importance of controlling HVAC/DC interference​.

Mitigation Strategies

Grounding and Shielding Solutions

Optimized grounding designs reduce HVAC/DC interference and are crucial for protecting pipelines. Programs such as MALZ provide accurate calculations for grounding resistance, ensuring pipelines are safeguarded against interference from high-voltage systems. These designs are especially valuable in environments like solar farms and substations​.

Lightning Protection

Lightning strikes can severely impact pipeline integrity. Interference protection designs are developed to mitigate risks from both direct and induced lightning strikes. This includes calculating values like the shielding failure flashover rate, backflash rate and total flashover rate, which improve pipeline and attached aboveground appurtenance resilience​.

Corrosion and Monitoring Solutions

Advancements in corrosion monitoring techniques enable continuous tracking of pipeline EMF exposure, providing real-time feedback for adjusting cathodic protection systems. Maintenance protocols should prioritize areas exposed to high levels of interference to prevent long-term damage​.

Key Takeaways

HVAC/DC interference studies and EMF analysis are indispensable for ensuring pipeline integrity in today’s complex energy infrastructure. Regular evaluations and monitoring help mitigate risks and ensure the long-term safety and reliability of pipelines.

As energy transmission networks expand and evolve, proactive design and interference mitigation will become increasingly important for integrated infrastructure. Collaboration between energy transmission operators and pipeline owners is essential to ensure the safe and reliable coexistence of these systems.

TRC Can Help: Partnering for Resilient Pipeline Solutions

At the forefront of ensuring pipeline integrity in changing landscapes, TRC embraces the shift toward proactive interference mitigation and advanced EMF analysis. Our tested practitioners provide a seamlessly integrated approach, combining practical solutions with forward-thinking strategies. From precision modeling to innovative grounding and shielding designs, we enable pipelines to operate safely alongside high-voltage infrastructure.

TRC partners with clients to transform challenges into opportunities, offering direction-setting perspectives and resolutions that thrive. Together, we build resilient energy infrastructure, creating new possibilities in a world driven by adaptability and innovation.

Learn more by exploring our related services or contact us today with your questions.  

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Charles Venditti

Charles currently leads the Pipeline Integrity team at TRC, bringing his experience in upstream, midstream and downstream engineering and operations. In his role, he oversees projects supporting gas and liquids pipelines throughout North America with capabilities in risk analysis and management, integrity engineering, regulatory compliance, corrosion engineering and cathodic protection, and field services. Prior to TRC, Charles led an Upstream Regulatory Compliance team where he interfaced with state and federal regulators to influence development and implementation of new regulations, as well as revisions and application of existing regulations. He also spent several years in engineering and project management roles supporting Marathon’s refining operations. He is currently the President for the Indiana Oil and Gas Association, a chairman of the Technology and Regulatory Compliance committee with the Kentucky Oil and Gas Association, and serves on two other non-profit Boards. Charles has a BS in Chemical Engineering from Virginia Tech, an MBA from Malone University, certification in project management and is a licensed Professional Engineer in multiple states.