The problem that led to an explosion at a hydrogen filling station on 10 June near Oslo was an incorrectly mounted plug in a hydrogen tank in a high-pressure storage tank. Manufacturer Nel made the inquiry public and is establishing precautions.
Nel has now completed the on-site inspection of the high-pressure tank in cooperation with Gexcon and the relevant authorities. The assembly error with the plug concerned in one of the high-pressure accumulators led to a hydrogen leak. This leak produced a mixture of hydrogen and air that ignited.
With the problem now identified, Nel will conduct an inspection and integrity testing scheme for the high-pressure storage units with similar connectors. Besides, Nel has stated that it has initiated a program that describes new assembly, inspection and documentation procedures.
“Based on our investigations and analysis, we can conclude that the leak started in a specific plug assembly in one of the tanks of the high-pressure storage unit,” says Geirmund Vislie, Gexcon’s manager in charge. Although the fault has been established, the investigation will continue to find out what mechanism caused the leak to ignite.
As a result of the incident in Norway, the operator H2 Mobility also took four hydrogen filling stations in Germany off the grid in which Nel components were installed. Now that the problem has been identified, H2 Mobility is testing the hydrogen tanks at these filling stations according to the new procedures. After the acceptance test, the timing of which is not yet foreseeable, the hydrogen filling stations are to be connected to the grid again.