| Case Name |
Fire of leaked hydrogen due to misuse of a gasket at a solvent manufacturing plant |
| Pictograph |
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| Date |
March 28, 1996 |
| Place |
Kurashiki, Okayama, Japan |
| Location |
Chemical factory |
| Overview |
A fire occurred due to misuse of a gasket at a solvent plant. As the size of the gasket replaced on periodically exchanging of a catalyst was smaller than the standard one, it could not withstand the hydrogen pressure of operation, hydrogen leaked, and a small fire occurred. Furthermore, another gasket was damaged by the fire, a large quantity of hydrogen leaked, and the fire spread. As combustible gas in the piping was substituted with nitrogen at an early stage of the fire, damage was limited only to the immediate area. If the hydrogen leak could not have been stopped, fire extinguishing would have been difficult, and damage would have been greater. It is assumed that gasket management at a turnaround shutdown was the cause. |
| Incident |
At a solvent manufacturing plant, hydrogen leaked from a flange of hydrogen piping, and a fire occurred. As a gasket of a nearby flange was also damaged by the fire, a large quantity of hydrogen leaked and the fire spread. |
| Processing |
Manufacture |
| Individual Process |
Reaction |
| Chemical Reaction |
Addition |
| Substance |
Hydrogen, Fig2 |
| Succinic anhydride, Fig3 |
| Type of Accident |
Leakage, fire |
| Sequence |
On March 4th, 1996. A catalyst was exchanged periodically.
On March 6th. Operation of a plant starter. After raising the pressure of hydrogen gradually, the plant shifted to usual continuous operation.
On March 28th. Hydrogen leaked from a gasket of a flange, was ignited by static electricity, and a small fire occurred in thermal insulation.
10:25. A flange of an adjacent drain valve, of which thermal insulation was applied together with the leaked flange, was damaged. A large quantity of hydrogen leaked from the flange of the drain valve, and the fire spread. The plant was shut down urgently and employees carried out initial fire fighting and nitrogen substitution.
10:31. The fire department was notified about the fire. Four fire engines and eleven fire fighters turned out.
10:40. The fire was confirmed to have been extinguished. Injection of nitrogen was continued. |
| Cause |
During a periodic catalyst exchange, a gasket somewhat smaller than the regular one was used for rejoining the flange of the valve.
After operation restarted, as the effective width of the gasket was about 1/7 that of a regular one, it could not withstand the pressure of the hydrogen.
The gasket of the adjacent drain valve flange in the same thermal insulation was softened and damaged by the flames.
Therefore, a large quantity of hydrogen leaked and the fire spread. |
| Response |
An emergency shutdown
Initial fire fighting
Nitrogen substitution in piping |
| Countermeasures |
To prevent misuse of a gasket, management of construction at a turnaround shutdown was improved.
To detect a gas leak inside thermal insulation, inspection windows were installed in thermal insulation and gas leak checks were strengthened.
The flange itself was improved. |
| Knowledge Comment |
During a gas leak fire, it is essential to stop the gas leak. If the leak cannot be stopped, the danger of a fire and an explosion of leaking un-burnt gas would be very high.
If a leak cannot be stopped, fire extinguishing is impossible and only prevention of fire spreading is possible, so handling a fire caused by a gas leak would be very difficult.
It is difficult to detect a gas leak from piping covered with thermal insulation at an early stage. |
| Background |
The cause was miss management in construction, or human error of the person in charge. It is also considered that there was defective schedule management and material-handling management during a periodic catalyst exchange. |
| Incidental Discussion |
After a gasket exchange, a test is usually performed for leaks. The test after the exchange was passed at the time of this accident. Damaged parts may pass the test because the test time is very short. |
| Reason for Adding to DB |
Example of fire caused due to misuse of gasket |
| Scenario |
| Primary Scenario
|
Poor Value Perception, Poor Safety Awareness, Inadequate Safety Measure, Carelessness, Insufficient Precaution, Carelessness of Operator, Planning and Design, Poor Planning, Poor Repair Management Planning, Poor Hot Insulaton Design, Usage, Maintenance/Repair, Restration, Malfunction, Poor Hardware, Gasket Leakage, Secondary Damage, External Damage, Fire
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| Sources |
Fire and Disaster Management Agency, Fire accident with hydrogen leak from a solvent manufacturing plant. Accident cases of dangerous materials. 1996, pp.110-111.
High Pressure Gas Safety Inst. of Japan, The high-pressure gas protection overview. 1997 edition, pp.198-199 (1997).
|
| Physical Damage |
Some piping and thermal insulation were damaged by fire. |
| Financial Cost |
¥ 700,000. (Fire and Disaster management Agency). |
| Multimedia Files |
Fig2.Chemical formula
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Fig3.Chemical formula
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| Field |
Chemicals and Plants
|
| Author |
ITAGAKI, Haruhiko (Japan National Institute of Occupational Safety and Health)
TAMURA, Masamitsu (Center for Risk Management and Safety Sciences, Yokohama National University)
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