Release at a Dispenser of a Hrs
Minor leak in the break-away coupling for 35MPa dispenser of a refuelling station for buses.The leak developed in the break-away coupling during a controlled test refuel. The test was attended by the station operators staff. The leak occurred as the temperature was decreasing (the hydrogen is pre-chilled to between -33oC and -40oC prior to entering the dispenser).The dispenser was taken out of service until a replacement break-away coupling was installed by the manufacturer. The 70MPa dispenser remained operational.The dispenser system had been leak-tested during the installation/commissioning phase, however this had only been carried out at ambient temperature. It is believed that the leak was only present at low temperature.
Event Date
May 25, 2016
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
car body
Storage/Process Medium
Actual Pressure
35
Design Pressure
35
Location Type
Location description
City
Operational Condition
Currency
Lessons Learned
Lessons Learned
Leak test at ambient temperature may not be sufficient to identify leaks within systems cooled during normal operation. It is proposed that a leak test is conducted during commissioning at the minimum temperature expected during operation.A more refined automated leak detection logic needs to be developed and is under discussion with the manufacturer in order to capture this type of leaks when trained personnel are not present.
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
Report provided but confidential