Hydrogen valves
A hydrogen valve is an industrial control valve that has been specifically engineered for the secure handling of hydrogen in industrial applications, including chemical plants, energy generation, metallurgy, and infrastructure projects. Hydrogen is regarded as a pivotal energy resource of the future and a vital component for a climate-neutral industry.
Hydrogen has a long history of industrial use, yet its unique physical and chemical properties demand top-tier valve technology. The gas’s tiny molecule size, high diffusivity, and flammability necessitate the strictest standards in materials, design, tightness, and operational safety. Hydrogen valves are thus critical safety components in the industrial hydrogen economy.
One of the central challenges faced in the design of hydrogen valves is the selection of suitable materials. Hydrogen has the capacity to diffuse into many metallic materials and cause hydrogen embrittlement, which can significantly impair the mechanical strength and service lifetime of components.
Defects in castings are a particular target for hydrogen embrittlement. Depending on the application, there are increased requirements for testing and acceptance levels for casting quality that must be met. At elevated pressure and temperature, austenitic stainless steels are particularly resistant to hydrogen embrittlement.
It is vital that all seals and lubricants that come into contact with the process fluid are completely hydrogen-compatible. Achieving the highest possible material purity and implementing rigorous manufacturing quality controls are critical, given that even minor material defects have the potential to serve as diffusion points for hydrogen.
Hydrogen valves must meet the most stringent tightness requirements both internally and externally. Due to the small molecular size of hydrogen, conventional sealing concepts are often inadequate. Internally, depending on the application, soft-sealing systems for bubble-tight shut-off or metal seating systems with minimal leakage rates are employed.
In critical applications, redundant sealing concepts are preferred, in which a soft-sealing primary seal is secured by a metal-sealing secondary seal.
Externally, zero emissions is of central importance. Even the smallest leaks can result in the formation of flammable mixtures in enclosed spaces. For this reason, hermetically tight bellows sealing systems or particularly low-emission stuffing box systems (in accordance with ISO 15848) are preferred for hydrogen valves, as they guarantee the highest standards of tightness, even over more than 100,000 stroke cycles.
Additionally, hydrogen valves must be capable of withstanding extreme operating conditions. These range from cryogenic temperatures during storage in liquid state to high process temperatures, and from low-pressure applications to high-pressure systems with pressures exceeding 300 bar.
Due to the fact that hydrogen forms an explosive mixture with air even in low concentrations, hydrogen valves are subject to strict explosion protection requirements. All valves and accessories utilized in potentially explosive areas must be certified accordingly. This includes, in particular, positioners, sensors, and electric actuators, which are designed to be explosion-proof. It is essential that non-electrical components, such as pneumatic actuators and the valve design itself, are designed in such a way that potential ignition sources, including sparking, electrostatic charging, or impermissibly high surface temperatures, are avoided. The use of antistatic materials and coatings, as well as a robust mechanical design, is paramount in this regard.
Experience
ARCA has accumulated decades of experience in the development and manufacture of control valves for hydrogen applications. Rather than considering hydrogen valves as isolated individual products, we view them as highly integrated control solutions, precisely tailored to the respective process. The ECOTROL® series forms the technological basis for many industrial hydrogen applications.
Modular design
The modular valve platform offers flexible configuration options in terms of nominal diameter, pressure rating, material, sealing system, and internal trim. This feature enables precise adaptation of the valves to meet the specific requirements of various processes, such as electrolysis plants, storage and transport processes, chemical applications, or pressure swing adsorption plants. The design’s primary focus is on high control accuracy, long service life, and maximum operational safety, even under highly variable load and pressure conditions.
GUARDIAN program
A central element of ARCA’s hydrogen expertise is the GUARDIAN program. This comprehensive safety and service concept is based on three pillars: design and materials, testing and certification, and training and maintenance.
The latest findings on the hydrogen resistance of materials and components are incorporated as early as the development phase. In addition, extensive testing and acceptance procedures are carried out to ensure compliance with all relevant standards and guidelines.
Consultation
ARCA’s commitment to a consultation-oriented approach is unwavering. Rather than implementing standardized solutions, we develop customized valve concepts that are precisely aligned with local conditions and process requirements. The utilization of modern digital positioners, endowed with diagnostic capabilities and real-time data processing, ensures uninterrupted monitoring of valve status, thereby enhancing operational safety.
Safety and maintenance
When operating hydrogen valves, safety is inextricably linked to professional maintenance and qualified operation. Regular inspections and maintenance measures are essential to ensure long-term tightness, functionality, and operational safety of the valves.
ARCA provides plant operators with comprehensive services and training programs to support them in this regard. The specialized training courses offer in-depth knowledge on the operation, maintenance, and safety assessment of hydrogen valves. The courses cover both theoretical principles and practical aspects, including the early detection of wear, leaks, or potential hazards.
Maintaining the cleanliness of the valves is another safety-related aspect that is addressed. Contamination-free design is paramount, especially for high-purity hydrogen applications. ARCA employs specialized cleaning and testing processes to ensure that all components that come into contact with the process fluid are free of unwanted substances. This reduces the risk of atomic hydrogen formation and contributes significantly to the safe use of hydrogen in industrial plants.
Applications
Control systems for pressure swing adsorption (PSA)
ARCA provides advanced control technology that optimizes the pressure swing adsorption (PSA) process, which is utilized for the purifying of hydrogen from raw gas mixtures. The process enables the attainment of purity levels of up to 99.9999%, making it highly efficient. It is notable for its high control valve switching cycles, as the gas is systematically fed from one absorber to the next and subsequently returned.
Ensuring a tight seal of the control valves in both flow directions is paramount to maintaining the purity of the gas. The patented ARCA soft seal has demonstrated its reliability, with a track record of over 1 million switching cycles.
Hydrogen in power-to-X Applications (P2X)
Power-to-X Applications (P2X) are an important technology that enables the production of hydrogen using green or surplus electricity.
These applications generate a variety of products, including ammonia, methane, diesel, ethylene, methanol, and more, through subsequent processes. It is essential to ensure the proper control technology of these products to maintain safety and compliance standards.
Our esteemed group member, WEKA AG in Switzerland, is a leading manufacturer of cryogenic components and sets benchmarks in cryogenic technology.
The Swiss specialists are proficient in ensuring the safe and reliable operation under extreme conditions, ranging from temperatures as low as -253 °C to pressures of up to 1000 bar. Their expertise encompasses the liquefaction of gaseous hydrogen, its storage and transport, and the establishment of fuel supply systems for space travel.
Your contacts
Pascal Weyers Sales Engineer Compressor & Steel Industries
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