Event
- Event ID
- 400
- Quality
- Description
A hydrogen compressor had been shut down for repairs and was being put back into service when the explosion occurred, causing damage . The compressor was equipped with interchangeable in take and outlet valves, which had been exchanged during re-installation.
- 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
- compressor / booster / pump (valve)
- Failure mode
- internal explosion
- Initiating cause
- wrong installation
- Root CAUSE analysis
The discharge valve was installed in the intake position causing the cylinder head to blow off and release hydrogen to the atmosphere. Source of ignition unknown.
A CONTRIBUTION CAUSE could be related to a wrong execution of a maintenance/repair step. However, the fact that the two valves could be exchanged calls for a ROOT CAUSE on inadequate procedures and risk assessment.- Root causes
- Date entry in HIAD
- 01/11/2025
Facility
- Application
- Non-road vehicles
- Sub-application
- Aerospace
- Hydrogen supply chain stage
- All components affected
discharge valve,
H2 compressor- Process temperature range [C]
- ambient temperature (-50°C to +50°C)
- Location type
- Unknown
- Location
- countryside or desert
- Operational condition
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 0
Lesson Learnt
- Lesson Learnt
The event highlighted the importance of correct and unambiguous labelling of components, error-proof connections and accurate installation/repair instructions. The lack of these elements not only witness scarce attention to operative procedures, but it is also as well a sign of an inadequate risk assessment.
In fact, the workers involved should be well trained, also by making clear which would be the consequences of exchanging components or mounting them inverted.
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Release temperature [°C]
- 25
- Probable IGNITION SOURCE
- Explosion type
References
- Sources categories
- ORDIN
- Reference & weblink
Mishap no 60 in
P. L. Ordin, Review of hydrogen accidents and incidents in NASA operations, 1974, NASA TM X-71565
https://ntrs.nasa.gov/citations/19740020344Hankinson and Lowesmith, Qualitative Risk Assessment of Hydrogen Liquefaction, Storage and Transportation, FCH JU project IDEALHY, Deliverable 3.10 (2013)
confidential
(accessed October 2025)Lowesmith et al., Safety issues of the liquefaction, storage and transportation of liquid hydrogen: An analysis of incidents and HAZIDS, Int. J. Hydrogen energy (2014) https://doi.org/10.1016/j.ijhydene.2014.08.002
Also uptaken in US database H2TOOLS
https://h2tools.org/lessons/discharge-valve-installation-error
(accessed Decembr 2025)
