Event
- Event ID
- 803
- Quality
- Description
The vent occurred at a hydrogen refuelling station (HRS) of a research laboratory (not public) serving heavy- and light-duty vehicle. The affected dispenser was a 700-bar dispenser for light-duty use supplied by an on-site gaseous storage of approx. 600 kg.
The leak occurred due O-ring extrusion and/or failure, on a medium-pressure manual isolation ball valve (normally open). The valve was connected to the end plug of a medium pressure tank. The failure of an O-ring created an external leak which could not be isolated.
The released quantity were small, in the 1 to 2 kg range. The leak was audible, but the hydrogen did not ignite and activated a safety sensor.
This leak occurred during the recommissioning of the medium pressure system following extended downtime and rebuild of a system that had been originally installed at a different facility.- Event Initiating system
- Classification of the physical effects
- No Hydrogen Release
- Nature of the consequences
- Macro-region
- North America
- Country
- United States
- Date
- Component involved
- dispenser (gasket)
- Failure mode
- leak
- Initiating cause
- material degradation (ageing)
- Root CAUSE analysis
The INITIATING CAUSE was the failure of a O-ring.
The ROOT CAUSE is related not only to a material failure, but also to the fact that the event occurred at the recommissioning of the medium pressure system, originally installed at a different facility, and after extended downtime. Ageing may have played a role in this case.- Root causes
- Date entry in HIAD
- 30/08/2024
Facility
- Application
- Hydrogen refuelling station
- Sub-application
- HRS 70 MPa
- Hydrogen supply chain stage
- All components affected
H2 dispenser
- Process temperature range [C]
- ambient temperature (-50°C to +50°C)
- Process pressure range [MPa]
- high pressure (above 50 MPa)
- Location type
- Open
- Location
- populated area
- Operational condition
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 0
- Property loss (onsite)
- 0
- Post-event summary
This is a near-miss
- Emergency action
Probably just an automatic shut down
Lesson Learnt
- Lesson Learnt
The safety system worked as expected.
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Release temperature [°C]
- 25
- Release pressure [MPa]
- 70
- Probable IGNITION SOURCE
References
- Sources categories
- Scientific article
- Reference & weblink
A. Al-Douri et al., Populating the Hydrogen Component Reliability Database (HyCReD) with Incident Data from Hydrogen Dispensing, paper ID232, Proceedings of ICHS 2023
https://hysafe.info/uploads/papers/2023/232.pdf
(accessed August 2024)A detailed analysis was presented by Clark et al. at the 2024 Center for Hydrogen Safety Americas Conference
The resentation is behind a paywall, but the abstract is available on line:
https://proceedings.aiche.org/conferences/center-hydrogen-safety-confer…
(accessed January 2025)
