Hydrogen
Austenitic steel cast sliding gate valves for hydrogen applications
Hydrogen places the highest demands on plant and system components, and compact sliding gate valves made of austenitic steels effectively control the small, light molecules precisely and quickly. As a result, they ensure reliability and safety while significantly lowering energy consumption during operation and production.
By Sandro Caravita, Marketing, Schubert &
Salzer Control Systems GmbH
Austenitic steel sliding gate valves are a reliable solution as they have an extremely compact, light weight design and a remarkably high resistance to hydrogen-induced embrittlement.
Hydrogen is developing into a key technology for the energy transition in industry. Ideally, it can be generated inexpensively as well as in a climateneutral manner using surplus electricity from renewable sources, thus it plays a major role in the replacement of fossil fuels. However, the small size of its molecules represents a big challenge for plant and system components in process engineering, especially for valves as they are required to provide reliable function and high sealing integrity under demanding conditions. The problem: hydrogen molecules can easily penetrate many materials and change their structure. Valves made of ferritic, martensitic, and even some high-alloy steels are susceptible to hydrogen embrittlement, which can lead to considerable damage and material failure.
Choice of material is decisive for safety
One reliable solution is stop and control valves made of austenitic steels such as 1.4408 and 1.4404. These stainless steel alloys are characterised by their high resistance to corrosion. In addition, the nickel content guarantees a very robust resistance to hydrogeninduced embrittlement. The choice of quality materials is also pertinent when it comes to seals. Common solutions such as ethylene propylene diene monomer( EPDM) or fluoroelastomer( FKM) cannot be used without restrictions in the hydrogen environment. Hydrogen diffuses easily into the molecular chains. A sudden drop in pressure can lead to a sudden and unexpected expansion from the volume of stored hydrogen and lead to the destruction of the seal. To prevent material failure, the use of plastics should be reduced to a minimum. Where necessary, special plastics or – especially with high pressures – metallic seals made of copper are used to permanently ensure the function in the event of sharp, unexpected pressure drops.
Compact, fast and precise with a long service life
Sliding gate valves made of austenitic steels are a reliable solution for controlling hydrogen. They combine numerous advantages, especially for this application area. Their special construction principal results in an extremely compact design with a low weight, a high control speed, low
42 Valve World December 2025 www. valve-world. net