Event
- Event ID
- 1119
- Quality
- Description
A LH2 trailer/truck had delivered liquid hydrogen to a customer site and was travelling back empty to the base. The drivers noticed an increase in trailer pressure. To avoid the possibility of having the safety vent open while traveling on the road, they moved to an isolated area, parked and performed a controlled, manual venting of the trailer. The pressure was stabilised and they returned o the base without further incident.
The trailer was found to have a deteriorated vacuum, and repaired.
- 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
- LH2 tank (road tanker)
- Failure mode
- rupture, no ignition
- Initiating cause
- over-pressurisation (thermal insulation degradation)
- Root CAUSE analysis
The INITIAL CAUSE was over-pressurisation of the LH2 tank, which triggered the need of a venting.
The ROOT or INTERMEDIATE CAUSE was a loss of the thermal insulation capacity of the tank, due to deterioration of the vacuum between the external and internal shells of the LH2 tank.- Root causes
- Date entry in HIAD
- 09/09/2024
Facility
- Application
- Hydrogen transport and distribution
- Sub-application
- LH2 tanker
- Hydrogen supply chain stage
- All components affected
vacuum thermal insulation
- 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)
- 225
- Post-event summary
The emergency was handled by the drivers, by performing a manual venting to stabilise the internal tank pressure. It is unclear what this stabilisation consisted. Since the thermal insulation ability was deteriorated, it is to expected that the pressure would increased again once the vent was closed. probably, the tank was completely emptied.
- Emergency action
The emergency was quickly ended by the intervention of the drivers, who performed a manual pressure release operation.
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Released amount (kg)
- 8.3802517032551
- Probable IGNITION SOURCE
References
- Sources categories
- PHMSA
- Reference & weblink
Incident I-2003071007 of the US Pipeline and Hazardous Materials Safety Administration PHMSA:
https://portal.phmsa.dot.gov/analytics/saw.dll?Portalpages&PortalPath=%…
(accessed September 2024)
