CEN/TR 17924:2025-02-07 ‘Safety and control devices for burners and fuel appliances burning gaseous and/or liquid fuels. Guidance on hydrogen specific aspects’ has been finally published. The members of CEN/TC 58 and other experts from the heating appliance industry have worked intensively in the ‘Advisory Group Hydrogen’ over the last five years to develop this set of rules. The Technical Committee in the figawa Controls sector provided the impetus and participated in the DVGW research project ECLHYPSE, in which the theoretical findings of the regulations were metrologically verified by the GWI and DVGW-ebi.
This provides the heating appliance market with a meaningful guideline for the utilisation of hydrogen in domestic and commercial gas applications. The TR (Technical Report) takes into account the essential material data of hydrogen, hydrogen admixture in natural gas up to 20%, methane, propane and butane. They are used to analyse the risks associated with the use of hydrogen and take into account the experience gained over the last few decades in the use of gas.
It was found that the previous tightness limits for gas valves used with propane or methane can be retained. Gas valves used in the field do not have to differ from gas valves used today in terms of the materials used. The production tests can still be carried out with air and the actual internal and external tightnesses are largely dependent on the viscosity and gas pressure in the case of viscous flow. Bernoulli's law only applies to very large leakage rates in the event of a fault.
When analysing the risk, it is useful to consider whether a heater is on standby or in operation, what air purging takes place and how the leakage rates relate to the respective lower explosion limits. Various graphs in the hydrogen guideline clearly show ‘reduction measures’ for the various gas types in comparison with each other and that the real measured values with hydrogen and methane emphasise this.
In the appendices, various risk analyses are proposed as a basis for the use of hydrogen in heating appliances or forced draught burners.
The English-language guideline is intended as a supplement to EN 13611 with the associated component standards. It is part of the DIN hydrogen standardisation roadmap.
Publication CEN TR 17924
