Event
- Event ID
- 221
- Quality
- Description
A leak developed on a CGH2 tube trailer on the pigtail of one of the tube. The pigtail was cracked, possibly due to vibration. This trailer was tested the day before this incident and was found to be leak free.
The trailer consisted of 10 tube, and each tube has a pigitail. Trailers are tested for leaks every fill.
- 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
- piping (pigtail)
- Failure mode
- rupture, no ignition
- Initiating cause
- loss of tightness (road vibrations)
- Root CAUSE analysis
The INITIATING CAUSE was the cracking of a pigtail, probably mechanical vibration from the road.
Different degradation modes could be excluded, because trailer components are tested for leak by every filling.
A possible ROOT CAUSE could be a shortcoming in the design, but also a non-further understood generic material failure.- Root causes
- Date entry in HIAD
- 24/10/2024
Facility
- Application
- Hydrogen transport and distribution
- Sub-application
- CGH2 tube trailer
- Hydrogen supply chain stage
- All components affected
Hose
- Process temperature range [C]
- ambient temperature (-50°C to +50°C)
- Process pressure range [MPa]
- medium to high pressure (10 to 50 MPa)
- Location type
- Open
- Location
- highway or similar
- Operational condition
- Pre-event occurrences
The PHMSA report does not specify when the leak occurred. It is plausible to assume that it occurred when travelling or at the place of delivery.
- Description of the facility/unit/process/substances
The trailer was a 10-tube trailer. Each tube had a capacity of almost 30 kg. Each tube had a pigtail attached to a main manifold.
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 0
- Currency
- US$
- Property loss (onsite)
- 115
- Post-event summary
The content of one tube was lost (approximately 30 kg). Material loss amounted to 115 US$.
- Emergency action
The emergency actions are not reported. From the fact that the whole content of the tube was released, and from similar cases used as proxy, it can be reasonably assumed that the pigtail connection was isolated from the manifold, and the tube let leaking.
Lesson Learnt
- Corrective Measures
The trailer manufacturer investigated a changed of design, by adding additional support to the main manifold, to reduce the amount of vibration to the pigtail. If this improvement was eventually implemented, is not reported.
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Released amount (kg)
- 29.4
- Release temperature [°C]
- 25
- Probable IGNITION SOURCE
References
- Sources categories
- PHMSA
- Reference & weblink
Incident I-1990060084 of the US Pipeline and Hazardous Materials Safety Administration PHMSA:
https://portal.phmsa.dot.gov/analytics/saw.dll?Portalpages&PortalPath=%…
(accessed September 2024)
