Part II. Component-Based Regulations in Hydrogen Systems

In this second part, the technical regulations applicable to the different components that make up a hydrogen system are presented: valves, tanks, regulators, fittings, compressors, among others. Given the high demands in terms of safety, reliability, and material compatibility in hydrogen handling, these elements are subject to strict technical requirements defined by European and international standards.

Each component must meet specific criteria depending on its function, working pressure, operating environment, and gas exposure. In addition, evaluation processes, mandatory testing requirements, and regulatory trends shaping the sector’s evolution in the coming years are addressed.

1. Component-Based Regulations in Hydrogen Systems

Hydrogen systems comprise multiple components with differentiated functions: from gas storage and conveyance to its control, regulation, measurement, or use in vehicles. Each of these elements is subject to specific regulations covering aspects such as safety, pressure resistance, hydrogen compatibility, leak prevention, and performance in explosive atmospheres. Below are the main component types and the applicable technical standards:

1.1 Valves

Valves are critical components for controlling the flow of hydrogen at different points in the system (tanks, pipelines, refueling stations, vehicles). They are exposed to harsh conditions such as high pressure, low temperatures, pure hydrogen, and the risk of leaks or fire. Therefore, they must meet strict requirements for design, materials, tightness, and fire resistance.

Relevant standards:

• EN ISO 21011 – General requirements for valves in compressed gas systems.
• EN 12516 (Parts 1 to 4) – Calculation methods for the mechanical strength of pressure valves.
• EN ISO 15848 – Testing for fugitive emissions (external leaks).
• API 6D – Design and testing of valves used in gas transmission systems.
• API 607 – Fire testing for valves with actuators.
• ATEX 2014/34/EU – Applicable if valves operate in potentially explosive atmospheres.
• PED – Pressure Equipment Directive (for fixed installations).
• TPED – Transportable Pressure Equipment Directive (for transportable equipment).
• UNECE R134 – Valves installed in hydrogen vehicles.
• ISO 19880-3 – Components for hydrogen refueling stations (valves installed in dispensers or hydrogen compressors).
• ISO 19880-5 – Purge and relief valves in hydrogen refueling stations.
• ISO 10297 – Specifies requirements for the design, manufacture and testing of gas cylinder valves.
• EN 16668 – Valves installed in dispensers or hydrogen compressors.

1.2 Cylinders and tanks

Used for storing compressed (GH₂) or liquefied (LH₂) hydrogen, they must withstand pressures up to 700 bar or cryogenic temperatures, depending on the system type. Materials must be hydrogen-compatible and resistant to phenomena like hydrogen embrittlement and cyclic fatigue.

Relevant standards:

• PED – Pressure equipment (for fixed installations).
• TPED 2010/35/EU – Transportable pressure equipment (for mobile cylinders).
• EN ISO 11120 – Seamless steel cylinders for compressed hydrogen.
• ISO 16111 – Transportable storage systems for compressed hydrogen.
• ISO 19880-3 – Safety requirements for storage components in hydrogen stations.
• ASME Section VIII – Design criteria for stationary pressure vessels.
• ISO 9809 – Seamless cylinders for gases.
• ADR/RID – Safe road and rail transport of hydrogen.
• CSA B342 – Canadian equivalent for hydrogen cylinders.
• ISO 19881 – High-pressure hydrogen cylinders for road vehicles.
• UNECE R134 – Tanks in hydrogen vehicles.
• EN 1251 series – Cryogenic pressure vessels.
• ISO 21009 – Cryogenic storage.
• ISO 21029 – Portable cryogenic equipment.

1.3 Pressure regulators and limiters

They control hydrogen pressure throughout the system, preventing overpressure that could compromise safety. They must operate accurately and remain leak-tight under varying temperature and flow conditions.

Relevant standards:

• EN ISO 2503 – Pressure regulators for compressed gases.
• EN ISO 7291 – Pressure regulators for flammable gases.
• CSA CHMC 1 – Specific to hydrogen regulators in North America.
• ISO 19880-3 – Regulators used at hydrogen refueling stations.
• PED and TPED (depending on use).

1.4 Fittings and connections

Connections must be absolutely leak-proof, pressure-resistant, corrosion-resistant, and vibration-resistant. Due to its small molecular size, hydrogen requires superior sealing quality. Cracks or mechanical failure must also be prevented.

Relevant standards:

• EN ISO 8434 – Metallic fitting systems for fluids.
• ISO 19880-2 – Safety in hydrogen station couplings.
• ISO 19880-3 – Connectors and joints in refueling stations.
• SAE J514 / J1453 – Hydrogen fittings (especially for vehicles or mobile systems).
• SAE J2600 – Compressed hydrogen fuel storage systems for vehicles. Covers interfaces and connections on the vehicle side.
• PED and TPED (depending on use).

1.5 Instrumentation

Instruments such as pressure gauges, thermocouples, flow sensors, and leak detectors are essential for monitoring operating conditions and detecting risks. They must meet requirements for electrical safety, fast response, and ATEX compatibility.

Relevant standards:

• IEC 60079 (series) – Electrical equipment in explosive atmospheres.
• EN ISO 26142 – Hydrogen detectors (sensors and alarm systems).
• EN 50543 – Portable and fixed electronic detectors for hydrogen. Complements EN ISO 26142.
• EN 60079-0 – General requirements for electrical equipment in hazardous areas.
• IEC 61508 / 61511 – Functional safety of instrumented systems (SIS).
• EN 50465 – Combustible gas detectors in industrial facilities.
• NFPA 2 (USA) – Safety code for hydrogen systems.

1.6 Safety equipment

Includes pressure relief valves, rupture discs, automatic shut-off valves, and other devices that protect against overpressure or significant leaks.

Relevant standards:

• EN ISO 4126 (series) – Pressure relief devices.
• ISO 19880-6 – Part of the series for refueling stations, specific for pressure relief devices (PRD).
• API 520 / 526 – Design and selection of safety valves.
• EN 13648 – Safety shut-off devices for flammable gases.
• ISO 19880-3 – Safety equipment at refueling stations.
• ISO 23273 – Hydrogen system safety in vehicles.

1.7 Components for hydrogen vehicles

Hydrogen-powered vehicles feature specialized systems that must be type-approved according to specific safety, compatibility, and pressurization standards. This includes tanks, pipes, valves, sensors, and control systems.

Relevant standards:

• GTR No. 13 (Global Technical Regulation on hydrogen and fuel cells): A global harmonized framework under the UN World Forum for Harmonization of Vehicle Regulations. It is the basis for standards such as UNECE R134.
• EC 79/2009 – Historical regulation on hydrogen vehicle type approval (repealed, but still referenced).
• UNECE R134 – Current UN regulation on hydrogen components and systems in vehicles.
• UNECE R100 – Applicable to electric vehicles, also relevant for hybrid configurations.
• SAE J2579 – Fundamental SAE standard for fuel cell propulsion systems and hydrogen vehicles (general performance and safety requirements). Widely referenced in North America.
• ISO 23273 – Hydrogen system safety in vehicles.

1.8 Pipelines

Pipes carry hydrogen between different components. They are subject to high pressures, thermal variations, load cycles, and possible hydrogen embrittlement effects, requiring strict specifications for design, manufacturing, and testing. They must ensure tightness and gas compatibility.

Relevant standards:

• EN 13480 – Metallic industrial piping (pressure, design, manufacturing, testing, and documentation).
• ASME B31.3 / B31.12 – Codes for process piping and hydrogen systems. B31.12 is the most important standard for hydrogen piping in North America.
• ISO 15649 – Design of piping systems in industrial plants.
• ISO/TR 15916 – Hydrogen safety (guidelines on piping and materials).
• ISO 11114-1 / -2 / -4 – Compatibility of metallic materials with gaseous hydrogen.
• ATEX 2014/34/EU – If used in ATEX-classified zones.

1.9 Other relevant components

Includes compressors, heat exchangers, measurement systems, and refueling protocols. Precision, durability, and safety in these interfaces are crucial to ensuring the integrity of the overall system.

Relevant standards:

• ISO 19880-1 – Refueling stations – general requirements.
• ISO 19880-4 – Hydrogen compressors – technical and safety criteria.
• OIML R139 – Gas measuring devices – accuracy and traceability.
• SAE J2601, J2719 – Refueling protocols and hydrogen quality specifications.
• ISO 17268 – Refueling connectors for heavy-duty vehicles.
• API 617 / API 618 – Widely recognized API standards for centrifugal and reciprocating compressors, respectively.

Document updated in July 2025

2. Evaluation and Certification Processes

The safe implementation of hydrogen systems requires a robust evaluation and certification framework, where specialized organizations verify regulatory compliance through:

1. Risk assessment (e.g., leaks, material embrittlement).
2. Component testing under extreme conditions (pressure, temperature, cycling).
3. Final certification ensuring compliance with directives (PED, ATEX) and technical standards (ISO, ASME).

These processes — carried out by notified bodies and accredited laboratories — are the final quality barrier before commercialization, especially critical in high-pressure applications (≥350 bar) or explosive environments.

2.1 Notified Bodies and Certification Bodies

Notified bodies are entities authorized by the European Union to assess and certify that products meet the requirements of applicable directives, such as the Pressure Equipment Directive (PED 2014/68/EU) or specific hydrogen regulations. These bodies perform audits, tests, and issue certificates to ensure compliance. Notable examples include TÜV Rheinland, Bureau Veritas, DNV, Applus+ Laboratories, among others.

On the other hand, certification bodies can be national or international and are typically responsible for verifying that processes and products meet specific technical and quality standards, such as:

• ISO 9001 (quality management)
• ISO 45001 (occupational health and safety)
• ISO 14001 (environmental management)
• ISO 19880-1 (hydrogen refueling infrastructure)
• ASME BPVC Section VIII (pressure vessels)

2.2 Mandatory Tests

To ensure safety in systems handling hydrogen, various tests are required according to international standards:

• Pressure test: verifies that the equipment or component can withstand maximum operating pressures without structural failure. This is usually performed according to standards such as EN 13445 or ASME Section VIII, using test pressures above design levels.
• Leak test: detects any hydrogen leaks, given its high flammability and ability to diffuse through materials. Methods include mass spectrometry, hydrogen-helium sniffing, or sensor detection, as indicated in standards like ISO 26142 or ISO 16111.
• Hydrogen embrittlement resistance: evaluates a material’s ability to resist hydrogen-induced embrittlement, a phenomenon that can cause internal cracking and premature failure. This is tested using standardized procedures (e.g., in ISO 11114-4) under controlled hydrogen exposure.

2.3 Required Marking and Technical Documentation

The CE marking is mandatory for products that comply with applicable European legislation, such as the Pressure Equipment Directive (PED), the Electromagnetic Compatibility Directive (2014/30/EU), or the Machinery Safety Directive (2006/42/EC), where applicable. This marking must be accompanied by technical documentation including:

• Detailed product description and technical specifications (materials, dimensions, max operating pressure, etc.).
• Test results, including references to reports and certificates issued by authorized bodies.
• Instructions for use, installation, maintenance, and emergency procedures, drafted according to standards like ISO/TS 19880-1 for hydrogen applications.
• Risk assessments and conformity analysis, following functional safety and safe design principles. These assessments are recommended to follow ISO 12100 (mechanical hazards) and methodologies such as FMEA or HAZOP for complex systems.

All this documentation must be available to competent authorities throughout the product’s lifetime and also facilitates traceability in case of inspections, updates, or technical incidents.

3. Trends and Future Perspectives in Hydrogen Regulation

3.1 Expected Evolution of European Regulations

European hydrogen regulations are constantly updated to adapt to market growth and new technologies. Greater specification in safety, efficiency and sustainability requirements is expected, with stricter standards for storage, transport and end use. The European Commission is working on initiatives such as the Hydrogen and Gas Markets Decarbonisation Package and the implementation of the AFIR regulation, which will establish mandatory criteria for refueling infrastructure. These actions aim to facilitate a safer, more competitive hydrogen market aligned with the objectives of the European Green Deal.

3.2 International Harmonization

Given the global nature of the hydrogen market, there is an ongoing effort to harmonize regulations between regions such as Europe, North America and Asia. Organizations such as ISO, IEC and the UN Economic Commission for Europe (UNECE) lead international standardization initiatives, while platforms such as IPHE facilitate technical cooperation between governments. This harmonization will facilitate international trade, ensure uniform safety levels and support technology interoperability, allowing products certified in one region to be accepted in others with minimal regulatory adjustments.

3.3 Technological Innovations and Their Impact on Regulatory Requirements

New technologies, such as high-temperature fuel cells, metal hydride hydrogen storage, carbon nanotubes, or AI-based IoT monitoring systems, are redefining the design and operational limits of hydrogen systems. These innovations require constant updating of regulations to include new test methods, structural integrity criteria, operational cybersecurity and risk assessment models. In this context, a performance-based regulatory approach is being promoted, allowing regulatory flexibility while maintaining high safety standards.

4. Conclusion

Compliance with regulations in hydrogen equipment and systems is essential to ensure the safety, quality and social acceptance of this emerging technology. Evaluation and certification processes are fundamental pillars to guarantee that products are reliable and conform to technical standards.

However, the current regulatory framework can represent a barrier to the development and rapid implementation of new hydrogen technologies due to its complexity and the constant need for updates. Therefore, it is crucial to move toward more flexible and adaptive standards that allow innovation without compromising safety.

At Lexier, we are aware that navigating this complex regulatory framework can be challenging. That is why we are committed not only to offering products that rigorously comply with all applicable regulations, but also to making our experience available to advise you in selecting the most suitable solutions for each link in your value chain. We work to make your commitment to hydrogen safe, efficient and successful.

Maintaining constant vigilance over regulatory changes and adopting best practices is key to success in this rapidly evolving sector.

5. Bibliography

European Hydrogen Safety Panel. (n.d.). Reports and recommendations on certification and safety in hydrogen systems. Retrieved from https://ehspanel.eu/

International Energy Agency (IEA). (n.d.). Hydrogen Safety Best Practices. Retrieved from https://www.iea.org/reports/hydrogen-safety

European Industrial Gases Association (EIGA). (n.d.). Guidelines for evaluation, testing, and certification in industrial gases, including hydrogen. Retrieved from https://www.eiga.eu/