Process, Controls & Plant Focus on: Pumps & Valves 24 | Plant & Works Engineering www.pwemag.co.uk February/March 2026 As hydrogen systems expand across industrial processing and energy applications, the performance of pumps, valves and flow-control equipment often depends on the smallest rotating components. These environments place heavy demands on such parts, and any change in friction, temperature or material behaviour can lead to wear. Chris Johnson, managing director of bearing specialist SMB Bearings, explores why bearings have a direct impact on the safety and stability of hydrogen systems. Keeping hydrogen systems steady Worldwide hydrogen demand increased to almost 100 million tonnes in 2024, up two per cent from 2023 and in line with overall energy demand growth, according to the full report from the IEA. As more projects come online, the equipment supporting these systems is working harder and for longer periods, which places added pressure on smaller mechanical parts. Miniature bearings sit at the centre of many of these applications, supporting components that control pressure, manage flow and maintain temperature within critical assemblies. If these bearings begin to wear or seize, the impact can surface long before a major component raises an alarm. For example, a blower in a fuel cell system can lose airflow and cause overheating. Similarly, other rotating components can experience issues that escalate quickly if not detected early. A bearing in a pump can create friction that leads to temperature spikes. In more extreme environments, these risks become even greater. In a cryogenic unit, stiffness caused by low temperatures can place strain on shafts and seals, raising the possibility of leaks. Hydrogen embrittlement One of the most significant factors is how hydrogen interacts with metals. Research from the University of Cambridge notes that hydrogen can enter the surface of bearing steels and alter their microstructure, making them more prone to cracking under load. As this process develops, small cracks can form and grow during normal operation. This behaviour, known as hydrogen embrittlement, raises the risk of sudden failure in bearings used in compressors, expanders or pumps. Combined with the very low temperatures required for hydrogen liquefaction or the high speeds found in rotating equipment, embrittlement adds further stress to parts that are already operating under tight tolerances. A 2023 report from Process Safety and Environmental Protection highlights that, while hydrogen offers a carbon-free alternative, its hazards — like embrittlement — demand a heightened focus on safety. An example can be seen in high-speed expanders used in a liquefaction plant. These machines rely on small bearings that must rotate at high speeds while resisting sudden temperature changes. If the bearing begins to crack due to embrittlement or loses lubrication at low temperatures, the expander can develop imbalance. As vibration grows, the machine may shut down to prevent further damage. What appears to be a large mechanical issue may later be traced to a bearing only a few millimetres in diameter. Fuel cell systems provide another illustration. These systems depend on steady airflow to maintain temperature in the stack. A small
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