Event
- Event ID
- 193
- Quality
- Description
The vent valve on a liquid hydrogen tanker vibrated open allowing a slight discharge hydrogen.
- Event Initiating system
- Classification of the physical effects
- Unignited Hydrogen Release
- Nature of the consequences
- leak no ignition
- Macro-region
- North America
- Country
- United States
- Date
- Component involved
- valve (generic)
- Failure mode
- leak, no ignition
- Initiating cause
- loss of tightness (road vibrations)
- Root CAUSE analysis
The INITIATING CAUSE was the loosening of the vent valve due to vibration while travelling.
The ROOT CAUSE could be attributed to a shortcoming in the design of the valve connection, or the failing to tighten correctly the valve.- Root causes
- Date entry in HIAD
- 20/01/2025
Facility
- Application
- Hydrogen transport and distribution
- Sub-application
- LH2 tanker
- Hydrogen supply chain stage
- All components affected
vent valve
- Process temperature range [C]
- cryogenic temperature (below -50°C)
- Process pressure range [MPa]
- low to medium pressure (below 2 MPa)
- Location type
- Open
- Location
- highway or similar
- Operational condition
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 0
- Currency
- US$
- Property loss (onsite)
- 0
- Emergency action
probably the drivers re-sealed the valve.
Lesson Learnt
- Lesson Learnt
Zalosh et al (see references), concluded their analysis of hydrogen transportation accidents till 1978 with the following conclusions:
"Finally, an encouraging aspect of the transportation incident compilation is that 71% of the hydrogen releases did not lead to an ignition. ... The relatively few ignitions may be due to either to lack of ignition sources or to the rapid dispersal of hydrogen into the atmosphere. In any event, the accident data provide further incentive t o transport , transfer and store hydrogen outdoors away from occupied areas."
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Probable IGNITION SOURCE
References
- Sources categories
- Zalosh
- Reference & weblink
Extract from Table III of Appendix A of Zalosh and Short
COMPARATIVE ANALYSIS OF HYDROGEN FIRE AND EXPLOSION INCIDENTS
Quarterly Report No. 2 for Period December 1, 1977 - February 28, 1978
https://www.osti.gov/biblio/6566131
(accessed September 2020)
