Event
- Event ID
- 369
- Quality
- Description
During the pump operation of a liquid hydrogen tanker, the vent valve was opened rapidly and the hydrogen detonated above the vent stack. The rapid valve opening was aimed at initiating a good pumping in the LH2 pump-vaporizer system. The vent valve was then closed, but the stack continued to flow hydrogen, which burned. The tanker pressure was 16 psig (ca. 1.1 bar).
- Event Initiating system
- Classification of the physical effects
- Hydrogen Release and Ignition
- Nature of the consequences
- Macro-region
- North America
- Country
- United States
- Date
- -
- Component involved
- valve (vent)
- Failure mode
- leak & ignition
- Initiating cause
- wrong operation
- Root CAUSE analysis
Apparently, the hydrogen release was intentional, but the ignition occurred due to the rapid opening of the vent valve. Following the detonation, the fire continued because the flap valve on the vent did not make a tight seal. The Teflon gasket was found scorched. According to the report, the vent stack was not purged allowing for a H2- air mixture in the stack. It is unclear if purging was foreseen by the procedure.
- Root causes
- Date entry in HIAD
- 16/11/2024
Facility
- Application
- Hydrogen transport and distribution
- Sub-application
- LH2 tanker
- Hydrogen supply chain stage
- All components affected
vent valve, stack
- Process temperature range [C]
- cryogenic temperature (below -50°C)
- Process pressure range [MPa]
- low to medium pressure (below 2 MPa)
- Location type
- Open
- Location
- industrial area
- Operational condition
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 0
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Probable IGNITION SOURCE
- Explosion type
References
- Sources categories
- ORDIN
- Reference & weblink
Mishap no 17 in
P. L. Ordin, Review of hydrogen accidents and incidents in NASA operations, 1974, NASA TM X-71565
https://ntrs.nasa.gov/citations/19740020344
