- The UK’s East Coast Cluster and HyNet North West projects have entered FEED execution with combined CO2 transport and storage infrastructure requiring specialist valve specifications that barely existed as a commercial product category five years ago.
- Dense-phase CO2 pipeline valve requirements are fundamentally different from both natural gas and liquid hydrocarbon service — the combination of high pressure, CO2’s aggressive dissolution behaviour in water traces, and the phase transition risk during depressurisation creates valve selection challenges that are exposing significant gaps in existing standards.
- Global CCUS project investment exceeded $15 billion in 2025 across over 40 active projects, making carbon capture infrastructure one of the fastest-growing segments in the industrial valve market.
CCUS Infrastructure: A New Frontier for Industrial Valve Engineering
Carbon capture, utilisation and storage (CCUS) is moving from demonstration project to large-scale industrial infrastructure with a speed that is catching much of the engineering supply chain somewhat unprepared. The valve requirements for CCUS projects are genuinely novel — not simply a variation on existing oil and gas or chemical plant specifications, but a distinct set of challenges that require fresh thinking on materials, design and testing.
The core issue is the behaviour of CO2 under the pressure and temperature conditions of transport pipelines and injection wells. Dense-phase CO2 — the supercritical or high-pressure liquid state in which CO2 is transported for efficiency — is an extremely aggressive solvent for moisture. Even trace water contamination, measured in parts per million, can form carbonic acid that attacks carbon steel at rates that would be unacceptable in any pipeline intended for multi-decade service. The combination of CO2 corrosion, the risk of hydrate formation at certain pressure-temperature conditions, and the severe consequences of pressure let-down (where CO2 can flash to gas and cause extremely rapid chilling — dry ice formation — at valve trim surfaces) creates a valve specification challenge that the industry is still working through.
The UK’s East Coast Cluster: A Case Study in CCUS Valve Procurement
The East Coast Cluster — a consortium including bp, Equinor, Shell, TotalEnergies and Eni — is developing the Northern Endurance Partnership CO2 transport and storage infrastructure to serve the Net Zero Teesside and Zero Carbon Humber industrial clusters. The infrastructure involves an onshore pipeline network collecting CO2 from industrial emitters across Teesside and Humberside, an offshore pipeline crossing to storage sites in the southern North Sea, and the injection well infrastructure for CO2 sequestration.
The CO2 pipeline will operate in dense phase — above the critical pressure of 73.8 bar and at temperatures that maintain CO2 in a supercritical or liquid state. Pipeline design pressure is in the Class 600 to Class 900 ANSI range (approximately 100–150 bar), with pipeline diameter varying from 16 inches on the collection network to 24 inches on the main trunk line. Block valves along the pipeline are required at intervals not exceeding 20 km, consistent with the requirements for high-consequence area classification pipelines.
The valve specification for the East Coast Cluster mainline block valves reveals the challenges immediately. Carbon steel bodies — even low-temperature grades like ASTM A352 LCC — cannot be used without internal corrosion protection if any possibility of water ingress exists. The project specification requires either stainless steel body construction (316L or duplex), carbon steel with corrosion-resistant alloy (CRA) internal coating validated for CO2 service, or carbon steel with proven inhibition systems and dry CO2 operation maintained by process control. The third option is the most economical but requires a level of operational discipline that adds risk — any operational upset that introduces water traces into a system designed for dry CO2 service can cause rapid and severe corrosion damage.
Dense-Phase CO2 Valve Design: What Actually Works
The valve design that has emerged as the dominant choice for CO2 mainline isolation duty is the trunnion-mounted ball valve with stainless steel or duplex body, metal seats, and antistatic design. The metal seat requirement deserves explanation: the risk of CO2 flashing to gas during valve operation — particularly in emergency shutdown scenarios where a valve may need to close rapidly against high differential pressure — creates a potential for rapid chilling at the valve seat that can destroy soft seat materials like PTFE or reinforced nylon in a single operating cycle. Metal-to-metal seating, while requiring higher operating torques and more powerful actuators, eliminates this failure mode entirely.
The stem seal arrangement also requires careful attention. CO2 is an efficient plasticiser for many elastomers — it permeates into the elastomer matrix at high pressure and then causes explosive decompression damage when pressure is suddenly released. The NORSOK M-710 standard for qualification of non-metallic seals in CO2 service provides the framework for seal material qualification, requiring rapid gas decompression (RGD) testing that simulates the most severe decompression scenarios the valve is likely to experience in service.
For control valves in CO2 service — used at compressor station inlet and outlet, at custody transfer metering stations, and at injection wellheads — the trim design must account for the thermodynamic behaviour of CO2 near its critical point. The specific heat capacity and compressibility of dense-phase CO2 change dramatically near the critical point (31.1°C, 73.8 bar), making conventional control valve sizing calculations potentially inaccurate. ISA 75.01 and IEC 60534-2 valve sizing equations require modification for CO2 service, and the major control valve manufacturers — Emerson, Flowserve, Samson — are developing CO2-specific sizing tools and trim designs to address this.
HyNet North West: Where CCUS Meets Hydrogen
HyNet North West, the industrial decarbonisation cluster centred on Merseyside and North Wales and developed by a consortium including Progressive Energy, National Grid and Eni, adds a further dimension to the valve engineering challenge. HyNet involves both CO2 transport from industrial emitters and blue hydrogen production from natural gas with carbon capture — meaning the valve infrastructure must handle both dense-phase CO2 on the capture and transport side and high-purity hydrogen on the distribution side.
The hydrogen service requirements — resistance to hydrogen embrittlement, low-leakage packing systems suitable for small molecule gas, and ATEX-rated actuators for Zone 1 hydrogen atmosphere — are in some cases in direct tension with the CO2 service requirements. Valve specifications that bridge both services require careful engineering judgement, and the project teams at HyNet are working closely with manufacturers to develop specifications that are genuinely fit for purpose rather than simply transferring specifications from adjacent industries.
Global CCUS Projects: A Valve Market Growing Fast
Beyond the UK clusters, CCUS infrastructure investment is accelerating globally. ExxonMobil‘s proposed Gulf Coast carbon capture hub in Louisiana — potentially the world’s largest CCUS project with a CO2 capture capacity of 100 million tonnes per year at full build-out — would if sanctioned represent an extraordinary valve procurement exercise. Equinor‘s Northern Lights project in Norway, the world’s first commercial CO2 transport and storage service open to third-party users, is already in operation and providing real-world operational data on CO2 pipeline valve performance.
In the United States, the Inflation Reduction Act’s enhanced 45Q tax credit for CO2 sequestration has catalysed a surge of CCUS project development. The Midwest Carbon Express pipeline, proposed by Summit Carbon Solutions, and the Navigator CO2 Heartland Greenway pipeline are among the large-scale CO2 transport networks in development that would collectively require thousands of mainline isolation valves and control valves in CO2 service.
For valve manufacturers, the CCUS market represents both opportunity and obligation. The opportunity lies in the growing demand for specialist CO2 service equipment. The obligation is to invest in genuine product development — CO2-specific design features, materials qualification, and testing — rather than simply relabelling existing products as CO2-compatible and hoping for the best. The projects are sophisticated, the operators are serious, and the consequences of valve failures in CO2 pipeline service are significant enough that engineering rigour, not marketing, will determine which manufacturers succeed in this emerging market.