More than 600 billion cubic meters of hydrogen are produced each year world-wide for the process industry. The technology for using hydrogen as an energy source in combustion engines or via fuel cells is now ready to replace petroleum products in the future.
The advantages of hydrogen as an energy carrier are:
• Neutral CO2-footprint
• Flexible energy storage: in liquid or gaseous form
• Power to X: flexible us as an energy supplier in fuel cells, fuel in combustion engines and as a coke substitute in steel production. With the addition of CO2, it can also be used as a fuel and combustible.

Technical challenge for safety valves in hydrogen applications:
• Storage and transport of hydrogen cryogenic (up to -253 °C)
• in refuelling systems pressures of up to 900 bar for cold liquefied hydrogen, in future up to 900 bar
• Use of materials being insensitive to hydrogen embrittlement

Recommendation:
• Austenitic steels (1.4404, 1.4408) for wetted parts
• stellited discs and nozzles for cryogenic temperatures (from 150°C to absolute zero) for best sealing results