Event
- Event ID
- 66
- Quality
- Description
The driver of a liquid hydrogen tanker noticed a small plume at the rear while traveling on a highway. He pulled over and found that the manual vent valve had opened due to vibration. The valve was tightened and no further incident occurred during the rest of the trip. The vent valve was thoroughly inspected upon arrival back at the base terminal, but no problem could be found.
- 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
- flange (bolts)
- Failure mode
- leak, no ignition
- Initiating cause
- loss of tightness (road vibrations)
- Root CAUSE analysis
INITIAL CAUSE was the opening the manual vent valve due to vibration.
The ROOT CAUSE was probably a design which did not took into account the whole range of mechanical solicitations which the pressure control system of the tanker could experiment when travelling.- Root causes
- Date entry in HIAD
- 31/12/2024
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)
- 30
- Post-event summary
10 kg went lost
- Emergency action
The driver closed the valve.
Lesson Learnt
- Lesson Learnt
This incident is very similar to other, such as the HIAD_070, which attributed to road vibrations the opening of the vapour return valve.
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Released amount (kg)
- 9.7
- Probable IGNITION SOURCE
References
- Sources categories
- PHMSA
- Reference & weblink
Event incident ID I-1990040021 of the PHMSA database (Pipeline and Hazardous Materials Safety Administration, 1996),
https://portal.phmsa.dot.gov/analytics/saw.dll?Portalpages
(accessed September 2024)
