Event
- Event ID
- 561
- Quality
- Description
A full liquid hydrogen tanker was approaching a stop at a vehicle weight station, when the driver noticed vapours coming from the tank vent. The driver parked the vehicle, inspected the tanker and found that the manual vent valve had opened slightly about 1/4 turn. The driver tightly closed the valve and all venting stopped. The vehicle proceeded to customer destination without further incident (approximately 3 hr driving).
- 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 INITIAL CAUSE of the release was a partially open valve.
The ROOT CAUSE seems to be the lack of detailed step transport management procedure.- Root causes
- Date entry in HIAD
- 01/01/2020
Facility
- Application
- Hydrogen transport and distribution
- Sub-application
- LH2 tanker
- Hydrogen supply chain stage
- All components affected
manual 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
- Pre-event occurrences
The tanker was full
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 0
- Currency
- US$
- Property loss (onsite)
- 350
- Post-event summary
A negligible amount of hydrogen was released.
- Emergency action
The drivers stopped at a truck parking place and called the alarm number. The local police department gave permission to release pressure from the tanker . The fire fighters were called to stand by. The pressure was released without problems.
Lesson Learnt
- Corrective Measures
The operative procedure was modified to require the driver to ensure that the valves are securely closed before departing, at the loading and unloading locations, and during all safety checks.
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Probable IGNITION SOURCE
References
- Sources categories
- PHMSA
- Reference & weblink
Incident I-1998030280 of the US Pipeline and Hazardous Materials Safety Administration PHMSA:
https://portal.phmsa.dot.gov/analytics/saw.dll?Portalpages&PortalPath=%…
(accessed September 2024)
