Event
- Event ID
- 75
- Quality
- Description
- The driver of a liquid hydrogen tanker noticed a small vapour plume in his mirror while driving. The driver stopped and found the packing nut had loosened on the vapour recovery valve causing the valve to crack open. The driver closed the valve and tightened the packing nut. The vapour stopped and the driver continued on to complete trip without further incident.
- Event Initiating system
- Classification of the physical effects
- Unignited Hydrogen Release
- Nature of the consequences
- Leak No Ignition (No additional details provided)
- Macro-region
- North America
- Country
- United States
- Date
- Main component involved?
- Flange (Bolts)
- How was it involved?
- Rupture
- Initiating cause
- Loss Of Tightness (Road Vibrations)
- Root causes
- Unknown (No additional details provided)
- Root CAUSE analysis
- The INITIATING cause of the hydrogen release was the loosening of valve packing nut.
The ROOT CAUSE was identified by the PHMSA report with over pressurisation. However, the loosening of the packing nut could more plausibly be attributed to road vibrations.
Facility
- Application
- Hydrogen Transport And Distribution
- Sub-application
- LH2 tanker
- Hydrogen supply chain stage
- Hydrogen Transport (No additional details provided)
- All components affected
- packing nut, valve
- Location type
- Open
- Operational condition
- Pre-event occurrences
- Unknown if the tanker was containing liquid hydrogen or only cold hydrogen vapour.
Emergency & Consequences
- Number of injured persons
- 0
- Number of fatalities
- 0
- Environmental damage
- 0
- Currency
- US$
- Property loss (onsite)
- 3
- Property loss (offsite)
- 0
- Post-event summary
- PHMSA reports a minimal loss of hydrogen of 60 GCF, which probably correspond to 0.2 kg
- Emergency action
- The fire brigade made use of an infrared camera to measure the temperature of the cylinders, and excluded overheating. The body of the cylinders resulted entire without other losses. The fire brigade team recovered the still loaded trailer, without need to remove gas.
Event Nature
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Presumed ignition source
- No ignition
References
- Reference & weblink
Event incident ID I-1991110674 of the PHMSA database (Pipeline and Hazardous Materials Safety Administration, 1996),<br />
https://portal.phmsa.dot.gov/analytics/saw.dll?Portalpages<br />
(accessed September 2024)
JRC assessment
- Sources categories
- PHMSA
