ChemiCAl industry
Comparison of emission tests with helium and hydrogen for graphite gaskets
Hydrogen ’ s potential to revolutionise our energy landscape is undeniable .
Its clean nature , versatility , and ability to store renewable energy make it a compelling option for a sustainable future . From powering vehicles to storing renewable energy , hydrogen is making waves as a potential significant change in the energy landscape .
By Ralf Vogel , ESA
About the author Ralf Vogel is a mechanical engineer and has been working in the sealing industry for 28 years . Currently , he is the Technical Director of the European Sealing Association .
H 2 molecules .
Hydrogen and helium are both gases and can leak if not properly contained . However , there are some differences between the two in terms of their properties and behaviour when it comes to leakage . Hydrogen is the lightest and most abundant element in the universe . It is highly flammable and can form explosive mixtures with air . Hydrogen gas is colourless , odourless , and tasteless , making it difficult to detect leaks without specialised equipment . Hydrogen molecules are small and can easily escape through tiny openings or leaks in containers or pipelines . Helium , on the other hand , is an inert gas and is non-flammable . It is also colourless , odourless , and tasteless . Helium is lighter than air and can quickly disperse into the atmosphere if released . While helium is not as prone to explosion or combustion as hydrogen , it can still pose safety risks if it displaces oxygen in enclosed spaces . In terms of leakage detection , hydrogen leaks can be detected using various methods such as hydrogen sensors , gas detectors , or by using soapy water to check for bubbles at potential leak points . Helium leaks are measured using similar methods , but helium is often used as a tracer gas in leak testing due to its low concentration in the atmosphere . It is important to handle both hydrogen and helium with care and follow proper safety protocols to prevent leaks and ensure the safety of personnel and equipment .
Gaskets
Gasket testing for hydrogen involves evaluating the performance and integrity of gaskets used in hydrogen systems . Since hydrogen is a highly flammable and reactive gas , it is crucial to ensure that gaskets can effectively contain and prevent leaks of hydrogen gas . Here are key aspects of gasket testing for hydrogen :
• Material compatibility : gaskets must be made from materials that are compatible with hydrogen gas . Common materials used for hydrogen gaskets include stainless steel , graphite , and certain elastomers . The selected material should have low permeability to hydrogen and be resistant to embrittlement or degradation caused by hydrogen exposure .
• Leak testing : gaskets are subjected to various leak testing methods to verify their effectiveness in preventing hydrogen leaks . These tests may include visual inspection , pressure decay testing , bubble testing , or helium leak testing . The goal is to ensure that the gasket forms a reliable seal and does not allow any hydrogen gas to escape .
• Compression and recovery testing : gaskets are often subjected to compression and recovery testing to assess their ability to maintain a proper seal under different operating conditions . This involves applying and releasing pressure repeatedly to simulate real-world scenarios and evaluate the gasket ’ s resilience and sealing performance .
• High-pressure testing : gaskets used in highpressure hydrogen systems may undergo
48 Valve World February 2024 www . valve-world . net