Seeing corrosion under insulation in real time: DNV qualifies Subtera's CUI detection technology

DNV has successfully completed the technology qualification (TQ) of Subtera’s passive terahertz sensor technology designed to detect corrosion under insulation (CUI) and the trapped moisture that causes it—a pervasive challenge in industrial plants. CUI is a leading cause of asset failure in industries such as oil and gas and chemicals. It has contributed to over 20% of major oil and gas accidents in the EU in the past 35 years, posing significant safety, environmental, and financial risks. 

Developed over a decade by Subtera, an ISO9001 certified organization that provides non-intrusive CUI and moisture detection solutions based at the Rutherford Appleton Laboratory in the UK, its technology enables real-time, non-intrusive visibility of pipe surfaces—without the need to remove insulation or disrupt operations.

A new standard in CUI detection

Subtera’s Pi360, is a handheld, cloud-connected CUI detection camera that allows asset integrity teams to efficiently screen operational pipework protected by non-metallic cladding. It detects corrosion, identifies moisture ingress, and assesses fabric layers—all while wirelessly transmitting data for analysis and reporting.

Technology qualification: a milestone for industry adoption

DNV is a recognized authority in pipeline integrity, developing industry-recommended practices such as DNV-RP-O501 for erosive wear, DNV-RP-F103 for cathodic protection, and DNV-RP-G109 for managing the significant threat of CUI. Leveraging decades of experience and a global network of experts, DNV provides expertise in materials qualification to ensure pipeline systems meet stringent safety standards. 

DNV’s TQ process provides a structured, rigorous framework for de-risking emerging technologies before deployment. Over 18 months, Pi360 underwent rigorous evaluation, with DNV assessing its photon-detecting analog sensors, user operations, and data processing capabilities to ensure reliability and accuracy under real-world conditions. In collaboration with Subtera, DNV identified and addressed operational and data analysis challenges, refining the system before full-scale testing. Following extensive validation, DNV issued a Technology Certificate for Pi360, confirming its readiness for industry adoption.

Hari Vamadevan, DNV
Hari Vamadevan, Executive Vice President, and UK and Ireland Director, Energy Systems at DNV

Hari Vamadevan, Executive Vice President, and UK and Ireland Director, Energy Systems at DNV commented: “DNV is thrilled to collaborate with Subtera on their groundbreaking technology, which revolutionizes CUI detection with advanced terahertz sensors. This collaborative work also paves the way for innovative data and digital applications across natural gas, hydrogen, and carbon capture pipelines, enhancing operational efficiency and safety. The work that Subtera is doing is exactly the kind of fresh thinking we need as we look for solutions to help accelerate the energy transition and we look forward to working with them in the future.”  

David Haskett, CEO of Subtera, added: “Working with DNV to qualify our core CUI detection technology has been a hugely beneficial process. During the process, DNV’s well-established methods and procedures meticulously evaluated our technology, its testing, and related system development. DNV’s rigorous approach has enabled Subtera to achieve higher levels of performance, thoroughness, and understanding.”  

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