Event
- Event ID
- 739
- Quality
- Description
During a preventive maintenance of a breakaway fitting, the adapter was found to be under-rated for the design pressure used in the dispenser. While the male straight-thread side of the "standard" fitting was rated to 7700 psig (530 bar), the female compression-tube end of the same fitting was rated to only 4900 psig (340 bar).
- Event Initiating system
- Classification of the physical effects
- n.a.
- Nature of the consequences
- Macro-region
- North America
- Country
- United States
- Date
- Component involved
- dispenser (hose)
- Failure mode
- n.a.
- Initiating cause
- n.a.
- Root causes
- Unknown
- Date entry in HIAD
- 13/07/2026
Facility
- Application
- Hydrogen refuelling station
- Sub-application
- Dispenser
- Hydrogen supply chain stage
- All components affected
breakaway
- 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
- unknown
- Operational condition
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 0
- Environmental damage
- 0
- Property loss (onsite)
- 0
Lesson Learnt
- Lesson Learnt
This is a near miss. The maintenance procedure worked as designed and was able to identify a mishap occurred probably during the delivery or the assembly for the breakaway of the dispenser hose or. The H2TOOLS report does not identify a root cause of this event.
Nevertheless, the event highlights the importance of the responsibility of the manufacturers and the need for end users (in this case the HRS owner and/or operator) to verify that the delivered/installed components meet the design specifications.- Corrective Measures
According to H2TOOLS "The adapter was replaced with a fitting of increased wall thickness meeting the design pressure rating."
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Probable IGNITION SOURCE
References
- Sources categories
- H2TOOLS
- Reference & weblink
Event of the US database H2TOOLS
https://h2tools.org/lessons/hydrogen-fueling-dispenser-breakaway-adapter
(accessed April 2026)
