Study of potential leakage on several stressed fittings for hydrogen pressures up to 700 bar

In order to improve risk analyses and influence the design of the future H2 systems, an experimental study on “real” leaks qualification and quantification was performed. In H2 energy applications, fittings appeared as a significant leakage potential and subsequently explosion and flame hazards. Thus, as a part of the “Horizon Hydrogène Energie” French program, four kinds of commercial fittings usually employed on H2 systems were tested thanks to a new high pressure test bench – designed, setup and operated by INERIS – allowing experiments to be led for H2 pressures until 700 bar. The fittings underwent defined stresses representative of H2 systems lifetime and beyond. The associated leaks – when existing – are characterized in terms of flow rate.

► Four kinds of commercial fittings were tested in terms of sealing up to H2 700 bar.
► A specific experimental installation was designed and setup.
► Despite drastic applied stresses, all fittings showed a very good reliability.
► Only two configurations gave leaks with very low quantified flow rates.
► Highlighted flow rates are close to the sensitivity thresholds of the test bench.