Release from a Hydrogen Pipeline
During maintenance work on a gas pipeline carrying hydrogen , a worker hears a leak at about at a bridge. The operator measures an concentration of 3% of the low flammability limit at few centimetres from the leak, and no detection beyond 25 cm. The area was highly ventilated. The technicians secured the area, isolated the section five hours later and started the controlled gas release. after two additional hours the pressure had reduced to zero and they started the nitrogen inerting. The pipe was repaired the next day.
Event Date
April 18, 2013
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
hydrogen pipeline, 80 mm diameter, 75 bar pressure
Storage/Process Medium
Actual Pressure
75
Design Pressure
75
Location Type
Location description
Countryside
Pre-event Summary
The leak was detected during maintenance work (what does not mean that it started during at that moment).The pipeline section concerned dated back to 1988.
Consequences
Number of Injured Persons
1
Currency
Event Nature
Emergency Action
14.30 detection of the leak. Area secured, 19:15 Isolation of the pipeline section 20:00 Start controlled emptying 23:00 Pipeline pressure at zero, start of nitrogen injection Day after: repair of the leak
Release Type
Release Substance
Hydrogen Release Concentration (%)
100.00
Release Pressure (bar)
75.00
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/43705/
(accessed September 2020)