Term
| Separating, cooling, smothering and penetrating |
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Definition
| Ways in which fire fighting foam extinguishes and/or prevents fire. (pg. 734) |
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Definition
| creates a barrier between the fuel and the fire (pg. 734) |
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Definition
| suppresses the release of flammable vapors and therefore reduces the possibility of ignition or reignition. (pg. 734) |
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Definition
| lowers the temperature of the fuel and adjacent surfaces. (pg. 734) |
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Term
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Definition
| lowers the surface tension of water and allows it to penetrate deep seated fires. (pg. 734) |
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Term
hydrocarbon fuels and polar solvent fuels. (pg. 734) |
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Definition
Class B foam is especially effective on |
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Term
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Definition
| Raw foam liquid before the introduction of water and air (pg. 735) |
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Term
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Definition
| device that introduces foam concentrate into the water stream to make the foam solution. (pg.735) |
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Term
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Definition
| Mixture of foam concentrate and water before the introduction of air. (pg. 735) |
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Term
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Definition
| Completed product after air is introduced into the foam solution. (pg. 735) |
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Term
| Low (20:1), Medium (20:1-200:1), and High (200:1-1,000:1). (pg. 736) |
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Definition
| Three types of foam expansion and their ratios (finished foam/foam solution). |
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Term
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Definition
contains hydrocarbon surfactants that reduce the surface tension of water in the foam solution, allowing for better water penetration. Coats and insulates fuels, preventing pyrolysis and ignition.
May be applied with fog nozzles, aspirating nozzles, medium and high expansion devices, and CAFS.
Mildly corrosive. Equipment must be flushed thoroughly after use. (pg. 736) |
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Term
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Definition
| Used to prevent the ignition or to extinguish fires involving combustible liquids. Manufactured with either synthetic or protein base (or a combination). (pg. 736) |
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Term
| 4 inches thick (foam blanket) |
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Definition
| A blanket of foam ______ inches thick should be applied to the fuel surface of unignited spills. (pg 737) |
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Term
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Definition
| mixing of water with an appropriate amount of foam concentrate to form a foam solution. For best results, concentrates must be proportioned at the specific percentage for which they are designed. (pg. 738). |
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Term
| Proportioning of Class B foams |
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Definition
Usually 3% rate for hydrocarbons and 6% rate for polar solvents.
(Multipurpose foams may be used at 3% concentrations regardless of the type of fuel). |
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Term
| Induction, injection, batch mixing, premixing (pg. 739) |
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Definition
| Four basic methods of proportioning. |
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Term
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Definition
| Method of proportioning foam in which the pressure energy in the stream of water is used to induct (draft) foam concentrate into the fire stream. In-line inductors and foam nozzle eductors are examples of this method. (pg. 740) |
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Term
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Definition
| Method of proportioning foam that uses an external pump or head pressure to force foam concentrate into the fire stream at the correct ratio for the flow desired. (pg. 740) |
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Term
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Definition
| Simplest and most accurate method of mixing foam concentrate and water. Less common with class B foams. Two disadvantages of this method are that in large incidents, the tank may empty before the fire is out or controlled and Class B concentrates must be circulated with tank water for a period of time to ensure thorough mixing before discharge. (pg. 741) |
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Term
| Premixing (foam solution) |
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Definition
| Commonly used method of proportioning. Pre-measured amounts of foam and water are mixed in a container. Typically used in portable fire extinguishers, wheeled extinguishers, skid-mounted twin agent units, and vehicle-mounted tank systems. |
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Term
| Two principles of foam proportioning device operation |
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Definition
1)The pressure of the water stream flowing through a restriction creates a venturi action that inducts foam concentrate into the water stream.
2)Pressurized proportioning devices inject foam concentrate into the water stream at a specified ratio and at a higher pressure than that of the water. (pg. 741) |
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Term
| Two types of foam proportioners |
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Definition
| in-line foam eductors and foam nozzle eductors. (pg. 742) |
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Term
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Definition
| the most common type of foam proportioner used in the fire service. Attaches to the pump discharge outlet, or at some point in the hose lay. Uses the venturi principle. (pg. 742) |
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Term
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Definition
| Same principle as the in-line eductor however it is built directly into the nozzle rather than into the hoseline. Its use can at times compromise firefighter safety because they cannot always move quickly without leaving their concentrate supplies behind. (pg. 742-743) |
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Term
| Compressed Air Foam Systems (pg. 747-748) |
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Definition
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Term
| Roll-on method, bank-down method, and rain-down method. (pg. 747) |
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Definition
Techniques for applying foam to a liquid fuel fire or spill |
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