| Case Name |
Explosion and fire of LPG tanks |
| Pictograph |
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| Date |
January 4, 1966 |
| Place |
Feyzin, France |
| Location |
Refinery |
| Overview |
A drain valve froze during drainage operation of a LPG tank at a petroleum refinery, which was located in the suburbs of Lyon in the south of France, and a large quantity of LPG leaked. Some of the leaked LPG evaporated, diffused, and spread to a road located 50-60 m away. It ignited due to the engine heat of a passing passenger car on the prefectural road where traffic was not completely regulated. The tank ruptured and an explosion occurred due to the BLEVE phenomenon, and four LPG surrounding tanks were destroyed. In addition, atmospheric pressure tanks such as jet fuel and crude oil tanks caught fire, and the refinery was destroyed. The cause was small human error, which seems to have been improper operation of the drain valve. Besides, incompleteness of the facilities in those days was a factor that caused the fire to spread, resulting in an enormous disaster. It was an important accident that seems to have been the origin of present regulations of LPG tanks. |
| Incident |
Valves could not be closed because they had become frozen during drainage operation of a LPG tank, and a large volume of LPG leaked (LPG seems to be propane). The leaked LPG vapor diffused, was ignited by a passing automobile, and exploded. Many tanks including the leaking tank were damaged by fire, and the refinery was almost destroyed.
Drainage operation: heavy materials in fluids are separated from the fluids which were stored or poured, and might have accumulated at the bottom of a vessel such as a tank and piping. The work to take out this accumulated heavy distillate is called a drainage operation. Drains in not only this accident but also light hydrocarbons and LPG often condense water and contaminate water. Freezing or generation of hydrate frequently occurs in LPG.
LPG: Abbreviation of Liquefied Petroleum Gas. Although paraffinic hydrocarbon of propane and butane are main contents as concrete chemical substances, olefin such as propylene and butene might also be contained. This is also called LP gas. |
| Processing |
Storage |
| Substance |
Propane, Fig2 |
| Type of Accident |
Leakage, explosion, fire |
| Sequence |
06:30 on January 4th, 1966, drainage operation of the tank started.
06:45, the operation finished. An attempt was made to close the valve, but it could not be closed.
About 07:05, an alarm sounded in the refinery, probably from a gas leak detector. At about the same time, traffic restriction on the expressway near the refinery started. However, the prefectural road was not restricted.
07:30, a passenger car drove along the prefectural road, and an explosion occurred. The tank where the leakage occurred was engulfed almost simultaneously in flames.
08:45, adjoining two tanks exploded. In addition, a spherical tank and an oil tank caught fire.
The fire was extinguished in the morning of the next day. |
| Cause |
1. The cause of the leakage seemed to be a very low temperature generated during drainage operation. The temperature of LPG fell due to flash-evaporation during the drainage operation of the tank, therefore, moisture froze. It is considered that the drain valve at the spherical tank bottom could not be closed.
2. The ignition source was the engine of an automobile that passed along the prefectural road.
3. An explosion in a LPG tank is a phenomenon later called BLEVE. Part of a steel plate at the upper tank was exposed to the flames. Its temperature increased, its strength was insufficient, and it ruptured. The blown LPG vapor was ignited by the flames in the circumstance and exploded. |
| Response |
A gas detector alarm sounded following leakage. Company's fire engines turned out and the traffic regulation was executed on the expressway. |
| Countermeasures |
1. To prevent a valve from freezing, the following should be done: duplication of a valve and optimization of the interval between duplicated valves, thorough education and training on appropriate valve use.
2. Countermeasures for facilities of a LPG tank.
(1) Installation of a dike. Prevention of diffusion of leaked LPG.
(2) Water spraying to cool the tank from the upper part. Prevention of overheating of the tank wall by fire by letting water flow along the tank's external surface.
(3) Fireproof structure for tank legs.
(4) To keep the proper distance between tanks.
3. The tank location. In particular, to secure the distance between a road and public facilities in which people gather. |
| Knowledge Comment |
1. LPG is most hazardous among light hydrocarbons in terms of a fire hazard. The reason why LPG is hazardous is shown below.
It easily becomes a very low temperature, diffusing along the surface because specific gravity of the vapor is heavier than air. It is very difficult to detect leakage of LPG which is colorless and odorless.
2. Sufficient facilities are necessary to store the hazardous material. Besides, it is essential to sufficiently ensure a keep out distance for safety. |
| Background |
1. The cause of the leakage was a valve operation error. The drain valve was serial valves, and two had been mounted. Its temperature was lowered by heat of vaporization, when LPG flashed, and there was freezing and/or generation of hydrate. The valve could not be closed, and melted afterwards, and LPG leaked from the tank. Therefore, the valve was duplicated. The first valve (upstream) opens fully and adjusts the opening of the second valve (downstream). There was not a lowered temperature at the first valve, because flash evaporation was not generated during this operation at the first valve, and it did not freeze. Both valves seemed to enter a low-temperature state. It is also considered that the low temperature of the second valve was propagated to the first valve, because both valves were located together.
2. The regulation of road traffic outside the refinery was not sufficient. There were two problems. One was the layout in the refinery, as the distance from the installation site of the LPG tank to the public road was only 50 or 60 meters. The other problem was insufficient communication between the municipality and inhabitants.
3. The cause of the explosion was the BLEVE phenomenon. The temperature did not rise at the lower part of the tank, because absorbed heat was used for heat of vaporization of LPG in lower part of a tank in which LPG was present. Exposed to flames at the upper part of the tank, which do not contain liquid LPG, the tank wall reached a very high temperature. Therefore, the strength of the tank wall made of steel decreased and finally it ruptured due to the internal pressure. The reason for the spread of damage was considered to be the insufficient distance between tanks.
4. The fire spread to other tanks. As the legs of the tank were made of steel and did not have fireproof structure, the strength of the legs was reduced by the high temperature, and the tank collapsed. The adjacent tank was a short distance away. The main causes from present knowledge are given above, but this knowledge was not available then. This major accident led to studies on the BLEVE phenomenon. |
| Sequel |
LPG tanks in Japan are regulated by a direction that takes the causes of this Fezin accident into consideration. |
| Incidental Discussion |
1. There have been some enormous accidents of LPG since this accident. There have been many examples from careless management. LPG, which has very dangerous characteristics, is also widely used in ordinary homes in Japan. Although there has not been a major accident, publicizing for ensuring safety is necessary.
2. There have been many reports and explanations on this accident. The origin of the accident was "the valves at the bottom of the LPG tank was opened, there was a leak." However, icing of moisture and hydrate generation from propane and butane are different phenomena. |
| Reason for Adding to DB |
Example of a major accident showing the hazards of LPG, which led regulations of LPG in Japan |
| Scenario |
| Primary Scenario
|
Poor Value Perception, Poor Safety Awareness, Insufficient Safety Education, Carelessness, Insufficient Understanding, Insufficient Recognition of Risk, Insufficient Analysis or Research, Insufficient Prior Research, No Design Apply to Danger, Planning and Design, Poor Planning, Insufficient Safety Measure, Regular Movement, Careless Movement, Wrong Valve Operation, Bad Event, Chemical Phenomenon, Freezing, Secondary Damage, External Damage, Leakage/Explosion, Failure, Large-Scale Damage, Many Ranks External Damage, Bodily Harm, Death, Bodily Harm, Injury, Loss to Organization, Economic Loss, Refinery Destructive Damage
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| Sources |
Frank P.Lees. Loss Prevention in the Process Industries. pp.890,898-899 (1980).
Tetsuzo Kitagawa, Leakage of liquefied petroleum gas by impossibility close sampling valve. Analysis of explosion hazard. pp.161-164 (1980)
Tokio Marine & Fire Insurance Co., Ltd.. Toru Miura, Study on LPG pressure storage tank accident. High pressure gas, No.237, pp.29-33 (1990)
Chemical Industries Association. Case of accident. LPG spherical tank. Case of accident and countermeasures. Safety countermeasure technology four for chemical plant. pp.230-231 (1979)
The Ministry of Construction, City Bureau. Japan City Center, Material 1. Combinat disaster case. Kei-Hin region disaster prevention improvement investigation and Kei-Hin region disaster prevention evaluation of impact report, pp.158-160 (1973)
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| Number of Deaths |
18 |
| Number of Injuries |
31 |
| Physical Damage |
One LPG spherical tank exploded. The fire spread to surrounding spherical tanks, and five tanks ruptured. There was great damage to jet fuel, crude oil atmospheric pressure tanks, and a refinery. |
| Financial Cost |
$18 million. (Tokio Marine & Fire Insurance). (conversion $70 million 1990) |
| Consequences |
Liquefied petroleum gas diffused to an expressway and a prefectural road. |
| Multimedia Files |
Fig2.Chemical formula
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Fig3.Area around tank
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Fig4.BLEVE explanation drawing
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| Field |
Chemicals and Plants
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| Author |
KOBAYASHI, Mitsuo (Office K)
TAMURA, Masamitsu (Center for Risk Management and Safety Sciences, Yokohama National University)
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