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13 Cards in this Set
- Front
- Back
A boil over is most likely to occur in a tank fire containing what product? |
It’s most likely to occur in a tank containing crude oil |
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What is the function of a bund? |
They are designed to hold 100% of the tanks contents (book) 110% (instructor) and their function is to contain the spill should a leak occur |
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Explain the process which can lead to a boil over in a storage tank |
Boil over takes many hours to occur. A layer of water is located at the bottom of the tank mixed with sludge and waste. When the thermal layer (travelling at 0.3m to 1m an hour) reaches the bottom of the tank, the water is instantly vaporised ( water to steam ratio 1700:1). This causes a piston effect which violently force unburnt product up through the fire. |
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Explain what could cause a slop over to occur |
Any pockets of water, for example from ill directed cooling lines that are interspersed within crude oil will be instantly heated to boiling point and expand to steam. The force of this expansion causes frothing of the top layers of the product which can then flow down the sides of the tank and in to the bunded area |
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Identify 2 types of installed systems that are associated with crude oil tanks. |
1) Foam pourers- designed to combat rim fires and smother the fire 2) Monitors- designed for full surface fires and bund fires and tank cooling. |
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True or false Exposures should be protected |
True |
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True or false Firefighters may enter bunded areas? |
False |
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True or false Sides of tanks should be cooled to maintain integrity? |
True |
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True or false You may apply water directly to the fire? |
False |
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True or false You should use aerial appliances and monitors? |
True |
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True or false You should use installed systems where possible? |
True |
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True or false You should always direct foam from the ground? |
False |
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True or false The heat layer rises |
False |