Release from Hydrogen Cylinders Storage of a Chemical Plant
A leak occurred on a rack containing 12 cylinders of hydrogen (50 l at 200 bar each) delivered by a lorry inside the fenced storage area of a bulb manufacturing plant. The plants safety manager closed access to the area, had the other lorry drivers on the site cut off their ignitions, and made them evacuate. The firefighters tested the air with an explosimeter and stopped the leak by closing the gate valve located on the outside of the rack. The valve was used to transfer hydrogen from the cylinders to their points of use. The rack had been delivered by a crane lorry. Each of the top four corners of the rack was fitted with a steel ring that was used to lift the rack off the lorry. The gate valve was opened when one of the four lifting chains used to lift the rack off the lorry accidentally wrapped around it.
Event Date
September 9, 2013
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
Immediate cause was the accidental opening of the main hydrogen valve during unloading of the lorry.
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
lorry equipped with a crane, hydrogen cylinder rack
Storage/Process Medium
Storage/Process Quantity
9
Actual Pressure
200
Design Pressure
200
Location Type
Location description
Industrial Area
Pre-event Summary
The lorry had been delivered to destination and the unloading of the rack of hydrogen cylinders was ongoing by means of the lorry crane
Consequences
Number of Injured Persons
6
Currency
Lessons Learned
Lessons Learned
According to the ARIA report (see references), the operator took the following two corrective measures: i) stopped deliveries of this type of rack , ii) replaced it by one with 16 cylinders, fitted with a cover and a central lifting ring.
Event Nature
Emergency Action
13:30 Hydrogen release started - The plants safety manager closed access to the area, had the other lorry drivers on the site cut off their ignitions, and commanded an evacuation.The firefighters tested the air with an explosimeter and stopped the leak by closing the gate valve.15:00 The firefighters left and the plant resumed normal operations.
Release Type
Release Substance
Hydrogen Release Concentration (%)
100.00
Release Pressure (bar)
200.00
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
Event description in the French database ARIA
https://www.aria.developpement-durable.gouv.fr/accident/44315/
(accessed September 2020)