Explosion on a Storage Vessel of a Chemical Plant
The accident occurred when a welder belong to a sub-contractor company was working on tank roof. The zeolite crystallization tank was being cleaned out with approx. 20% sulfuric acid. It was not pressurized and was vented to atmosphere. The worker had been asked to cut a larger inspection hole in tank top. He had not yet begun to cut, but possibly had already lit up the oxy-acetylene equipment, when a loud explosion was heard by many.Hydrogen evolution due to acid action on steel vessel walls was suspected to be the cause of the accident.
Event Date
November 18, 1996
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
The HSE communication does not give indications useful for drawing a root cause.
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
zeolite crystallization tank
Storage/Process Medium
Location Type
Location description
Industrial Area
Operational Condition
Pre-event Summary
The accident occurred when the tank was being cleaned. An additional intervention was planned, consisting in cutting a large inspection hole on the tank top. .
Consequences
Number of Injured Persons
5
Lessons Learned
Lessons Learned
Unknown
Event Nature
Emergency Action
Unknown
Release Type
Release Substance
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
Event description provided by HSE, original source confidential