Repurposing your pipelines for new service

A practical approach to repurposing pipeline infrastructure

As the energy system decarbonizes and new fuels enter the market, the operating requirements to transport these products are changing. Instead of building new infrastructure, energy companies are adapting existing and aging infrastructure to handle these products and their associated operating conditions.  Converting pipelines, pressure vessels, and other assets from one service to another has become a critical and cost-effective pathway to minimize the risk of stranded assets.  

However, asset conversion is not a simple switch. It is a complex, multidisciplinary process that requires operators to evaluate technical feasibility and demonstrate that safety and regulatory requirements will be met. Each conversion introduces a new set of uncertainties, as products behave differently: hydrogen can introduce material embrittlement risks, dense phase CO₂ introduces unique integrity challenges, including susceptibility to running ductile fracture and switching between liquid, and gas changes hydraulic pressure and flow dynamics, posing a risk for aging pipelines that were originally designed to transport a different product. 

Before any changes are made to the system, operators must determine whether the asset can safely operate under the new conditions. If it can’t, they need to know what upgrades are required to ensure the asset fitness for service, as well as whether regulators will accept the asset as fit for purpose.

What every pipeline conversion must get right 

A successful conversion project hinges on addressing two interconnected factors:

1. Procedural and regulatory compliance

Every conversion must meet or exceed applicable standards and demonstrate alignment with regulatory requirements. 

Depending on geography and application, this may include: 

These standards define how an asset can be reassessed, requalified, and approved for a new service. 

2. Technical assessment

Alongside compliance, a detailed engineering evaluation is required to assess:

  • Material compatibility and degradation risks, including challenges such as corrosion that may arise when operating conditions or transported products change.
  • Structural and integrity performance
  • Operational impacts, including changes in flow conditions and system capacity
  • Safety and risk exposure under new operating conditions

These evaluations must be tailored to the specific product and asset type, as no two conversions are identical. 

A systematic approach to asset conversion

Given the complexity involved, operators are using a structured, repeatable methodology for conversion of service:

Step 1: Define the conversion scenario

Identify the original design conditions and the new service requirements, including key operating parameters and fluid characteristics..

Step 2: Review applicable standards and asset records

Determine which codes and recommended practices apply to the specific conversion pathway and jurisdiction.

Identify available records relevant to the conversion and where there are gaps in the needed information.

Step 3: Perform multidisciplinary technical assessments

The asset being converted needs to be thoroughly assessed, looking at aspects that include:

  • Materials and fracture mechanics
  • Integrity and inspection
  • Hydraulics and flow assurance
  • Safety and risk
  • Regulatory and permitting
  • Techno-economics

This step involves collaboration across multiple specialist teams to capture all relevant risks. 

Step 4: Evaluate fitness for purpose

Using the information and assessments from the previous three steps, operators can then assess whether the asset can operate safely within acceptable risk limits, or if modifications or operating restrictions may be required to reduce risk. 

If there are information gaps identified during this activity, operators must identify ways to address them, such as laboratory testing or inspection.  

Step 5: Document and support regulatory approval

Clear documentation provides a transparent, defensible basis for the decisions made about the asset, which will allow regulators to verify assumptions and methodologies used and the conclusions reached.

The importance of integrated expertise

One of the biggest challenges in conversion projects is not the analysis itself - it is integrating insights across disciplines.

Conversion projects frequently require coordination between:

  • Materials laboratories and testing facilities
  • Pipeline and integrity engineering teams
  • Safety and risk specialists
  • Operational and end-use experts
  • Regulatory and permitting professionals
  • Costing engineers

The breadth of expertise required often means that multiple technical teams across different regions are involved. Coordination becomes more challenging when large expert teams from different regions are involved, but an integrated approach ensures that no critical factor is overlooked, and that decisions are made based on a complete system view.

A recent hydrogen blending assessment for Enbridge Gas illustrates how broad that system view must be. To evaluate the feasibility of introducing hydrogen into Ontario's natural gas network, DNV worked as part of a multidisciplinary team to assess pipeline and facility suitability, material compatibility, integrity, safety risk, operational impacts, greenhouse gas emissions, and end-user readiness across both transmission and distribution systems. The work started with system-wide screening and engineering assessments. The team then completed CSA-aligned risk studies and developed a phased implementation roadmap supported by techno-economic analysis. 

The outcome provided Enbridge with an evidence-based pathway for hydrogen adoption while continuing to meet customer and regulatory expectations. 

The project also highlights an important principle that extends to every project. Whether converting assets to accommodate hydrogen, CO₂, alternative fuels, or other products, operators need to know that this can be done while maintaining safe and reliable service.  Achieving this requires expertise from multiple disciplines, ranging from engineering and materials science to operations and regulatory compliance.

For hydrogen projects, these same principles are reflected in DNV's approach to re-evaluating existing infrastructure for new service, helping operators understand the technical and regulatory considerations involved in repurposing pipelines. 

What a systematic approach delivers 

When approached systematically, conversion of service enables operators to:

  • Extend the value of existing infrastructure
  • Reduce capital investment compared to new builds
  • Accelerate deployment of low-carbon energy systems
  • Maintain safety and regulatory confidence

Ultimately, it provides a practical pathway to asset conversion without compromising integrity or safety.

Take the next step

As the energy value chain evolves, conversion of service will be essential to preserving the relevance and performance of existing infrastructure. Understanding the process and applying it in a structured, defensible way is key to unlocking its full value.

8/17/2026 12:00:00 PM