【2026 Valve Selection】Key Technical Considerations for Valve Selection in the Hydrogen Era
Thread Content
This post was last edited by The one on 2026-5-23 01:23. The new role of hydrogen in the green transition: As the world moves toward a greener future, hydrogen is becoming an increasingly common fuel, with expectations that it will be widely used in various applications. For example, mixing hydrogen with natural gas in a certain ratio (usually 20%/80%) for use in gas turbine power generation can reduce carbon dioxide emissions by about 6% to 7% ； In the transportation sector, hydrogen fuel cells or liquid hydrogen can be used in vehicles with long ranges, serving as an important alternative fuel option.
The four main methods of hydrogen production: In refineries, hydrogen is traditionally produced from natural gas, oil, or coal through steam methane reforming or gasification processes – approximately 96% of hydrogen is currently produced using such methods. Electrolysis is the fourth method, accounting for only about 4% of the global hydrogen production volume at present.
Control valve design: Engineers must be particularly cautious when configuring control valves for gaseous or liquid hydrogen applications. Currently, hydrogen is being produced and transported on a large scale around the world in various forms (gaseous hydrogen, liquid hydrogen, liquid ammonia, and hydrogen carried by organic liquid hydrogen carriers LOHC). Each form requires appropriate pressure and temperature control in order to be transported in the form of pure hydrogen or a carrier to areas where sufficient hydrogen cannot be produced locally.
1. Material selection: Hydrogen embrittlement (also known as hydrogen-assisted cracking or hydrogen-induced cracking, HIC) is a complex process involving various microscopic mechanisms, one that is well-known to those working in related industries. In recent years, the industry has generally agreed that the causes of hydrogen embrittlement are complex, potentially resulting from the combined effects of various factors such as improper material selection, environmental conditions, the formation of metal hydrides, and hydrogen diffusion behavior; it is often difficult to attribute it to a single cause. The consequence of hydrogen embrittlement is a decrease in the toughness of the material due to the absorption of tiny hydrogen atoms. Steels with a tensile strength of less than about 145 ksi (1000 MPa) or a Rockwell hardness of less than HRC 32 are generally not affected by hydrogen embrittlement. Temperature is another key factor: in steel, hydrogen embrittlement is most pronounced at room temperature, but most metals are relatively safe above 150°C (302°F). Pressure also needs to be taken into account—the hydrogen partial pressure corresponding to the peak of hydrogen embrittlement is roughly between 300 and 1500 psi (20 and 100 bar).
It should be noted that hydrogen embrittlement can occur in steel and similar metals even at low hydrogen concentrations, depending on the temperature and pressure conditions. Materials suitable for hydrogen environments typically include austenitic stainless steels, aluminum alloys, copper, and copper alloys. Nickel and most nickel alloys should be avoided due to their susceptibility to severe hydrogen embrittlement. Gray cast iron, ductile iron, and malleable iron are also not suitable for hydrogen environments. Testing methods such as ASTM F1624 can be employed to grade alloys and coatings during the material selection phase, ensuring that their resistance to cracking is above the critical level for hydrogen-induced stress corrosion cracking. Tests should be conducted during the quality control process to assess the suitability of materials in a rapid and comparable manner. The NACE MR-0175 standard for upstream exploration and production environments, as well as the NACE MR-0103 standard for refining environments, help to define and specify the material requirements for control valves in hydrogen-rich environments.
Furthermore, the materials used for diaphragms and seals also need to be carefully considered. Although relevant research is still ongoing, the compatibility between hydrogen and polymers is still in the stage of extensive verification. Users need to understand the principle of gas explosive decompression, and hydrogen adds additional complexity for diaphragms. The packing materials for control valves may seem simple (such as spiral wound, PTFE, or graphite), but temperature and pressure factors must be given special consideration in hydrogen applications.
2. Leakage emissions: Leakage emissions refer to the accidental or unintended release of gases or vapors from pressure vessel equipment (such as faulty or improperly installed valves). Emissions that affect the environment, air quality, and human health fall into two main categories: greenhouse gas emissions (GHG) and air pollutant emissions. For valves, we mainly focus on greenhouse gas emissions. Dissipation emission testing is an umbrella term that encompasses a variety of testing procedures and methods used to test and evaluate the integrity of the stem seals (packings) of control valves – including straight-through valves, angle-seat valves, and regulators – as well as the external leakage at the valve body joints. Tests must accurately reflect actual operating conditions, covering temperatures ranging from low to normal levels, as well as extreme high-temperature and high-pressure environments.
The most commonly used testing standards for control valves include: ISO-15848-1/2, ANSI/ISA S93.00.01, ANSI/FCI 91-1, TA-Luft/VDI 2440, API-622, API-624, and API-641. Some companies have their own testing procedures, such as Shell SPE 77/300 and SPE 77/312. When specifying, selecting, or purchasing control valves, appropriate standards should be applied, and third-party certification should be provided to ensure that the correct valve stem diameter, material, and test gas are used. It should be noted with particular attention that the proof testing must cover not only the valve stem packing but also the sealing performance of all joints in the valve body throughout the entire cycle and under temperature changes.
About 60% of fugitive emissions come from valves, and up to 80% of the leaks in each valve are caused by the valve stem packing. Other leakage sources include the exhaust or pressure relief ports of solenoids, positioners, and control accessories. To prevent leaks, regular testing and maintenance are essential. For gas leakage emissions, using gas detection equipment helps to identify the source of the leak promptly.
3. Performance and Reliability The performance of a valve’s safety functions is measured by the \"Probability of Failure on Demand\" (PFD). From this calculation, the \"Safety Integrity Level\" (SIL) can be determined as an indicator of the system’s reliability and integrity; the levels range from 1 to 4, with level 4 being the safest and having the lowest failure probability, although it is rarely used. This is not a mandatory requirement for selecting a valve type or manufacturer, but it does provide a certain degree of confidence that the supplier is reliable and that its performance and safety meet international industry standards. If a control valve failure does not directly trigger the safety instrument function (SIF) to which it belongs, but may affect the proper operation of other related SIFs, additional analysis is required.
4. Control valve selection: Control valve selection is the process of matching the hydrodynamic properties of the system with those of the valve, with the aim of choosing control valves of appropriate size and type to meet the flow management requirements of the process system in the best possible way. Each control valve manufacturer, as well as some independent software companies, has developed its own valve selection platform based on the ANSI/ISA-75.01.01 and IEC 60534-2-1 standards. Different control valves have slight differences in their design features. Although all adhere to industry standards, the results of the selection evaluation may vary slightly due to the unique design of certain components in the valves produced by different manufacturers. Each selection should be accompanied by the manufacturer’s selection data sheet. Independent selection software can provide ideal size and performance data, but these figures are based on ideal conditions and may differ from those in actual operating scenarios. Reputable control valve manufacturers conduct verification tests to ensure that the calculated performance they specify is within the minimum acceptable tolerance range compared to the actual performance of the valves after installation. Additional tests can be requested if necessary to verify the precise flow rate, noise level, capacity, and pressure drop.