Hydrogen Explosion at an Aerospace Company
The event occurred in a support building at a test stand complex. The explosion destroyed two support buildings and severely damaged a large amount of equipment. No one was injured.Gaseous hydrogen leaked into one of the support buildings from a high pressure hydrogen gas system consisting of two storage tanks and connecting pipes. A location at one pipe had been attacked by galvanic corrosion on the outer wall for some time, thinning the wall. However, the pipe was not routinely under pressure. Just before the explosion, an isolation valve failed open, permitting hydrogen under a pressure of ca. 30 MPa (4300 psig) to enter the pipe and break the thinned wall. Hydrogen from the two 19.8 cubic meter (700 cubic foot) tanks was released into one support building and into the next one. An electrical contact in a sump pump motor starter relay arced when the sump pump in the first building began an automatic start sequence. The electrical arc ignited the hydrogen in one building and this explosion apparently initiated an explosion in the other building.
Event Date
October 31, 1980
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Cause Comments
Immediate cause was the failure of a high pressure valve into a low pressure pipe system with corroded wall. Root cause was probably related to design, specifically to he choice of the steel type for the piping.
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
aerospace component, support buildings, high pressure gas storage and pipes
Storage/Process Medium
Actual Pressure
300
Design Pressure
300
Location Type
Location description
Industrial Area
Operational Condition
Pre-event Summary
The original hydrogen pipe thickness was originally 15.2 mm (0.6 inch) wall thickness meant to handle high pressures, but had been thinned to only 0.41 mm (0.016 inch) thickness by galvanic corrosion.
Post-event Summary
Nobody was in the proximity of the bus. 20 days of operation were lost.
Lessons Learned
Lessons Learned
According to the referred source, "after that event, no mild steel was again used for high pressure hydrogen piping at that site".
Event Nature
Emergency Action
Unknown
Release Type
Release Substance
Ignition Source
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
L. C. Cadwallader and J. S. Herring, "Safety Issues with Hydrogen as a Vehicle Fuel Idaho National Engineering and Environmental Laboratory", INEEL/EXT-99-00522, September 1999
Section 4.1.6, page 46.
https://www.osti.gov/biblio/761801 (accessed August 2020)