Hydrogen Formation and Explosion in Zinc-Coated Sprinkler System
[NOTE: the attribution to hydrogen formation as cause of the explosion is 'probable 'but not fully demonstrated].Two explosions in two different sprinkler systems occurred, wit the same assumed cause.The first occurred at the premises of a company, where a service engineer was injured, even though the explosion actually moved out into the open air. The second occurred in the department store, where an installation contractor was burned because an explosion occurred in a large pressure storage tank in a small room with the result that the explosion was particularly powerful. On both occasions, the sprinkler system ignited and exploded due to a flammable gas in the system following the draining of water.It is believed that hydrogen formed by reaction of water with zinc in the inner coating layer of the pipes. The gas escaped during operational and maintenance work, whereby the pipes were opened in order to discharge the water. In the open air, the gas mixed with the oxygen, reaching a critical concentration, which was then ignited by sparks from tools.
Event Date
January 1, 2014
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
Zinc-coated pipe installations are often used in sprinkler systems and hydrogen can be formed due to a chemical reaction in the wet zinc-coated pipe system. Hydrogen in the water was secreted and ignited by sparks created during the emptying of water in the sprinkler installation
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
sprinklers, zinc-coated pipes
Storage/Process Medium
Location Type
Location description
Industrial Area
Operational Condition
Pre-event Summary
Maintenance works were ongoing, whereby the pipes were opened in order to discharge the water.
Currency
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