Fire Extinguishing Agents ARFF - FAA Airport скачать в хорошем качестве

Fire Extinguishing Agents ARFF - FAA Airport

This AC provides reference information on the following agents: • Primary aircraft fire extinguishing agents • Supplementary aircraft fire extinguishing agents • Other aircraft fire extinguishing agents The following definitions do not include numerical quantities. These can be found in NFPA 403, Table 5.3.1 (b), as well as additional agent quantities to be carried. #Primary Agents. Foam used for extinguishing aircraft fires should consist of an aggregation of bubbles of a lower specific gravity than that of hydrocarbon fuels or water. The foam should have strong cohesive qualities and be capable of covering and clinging to vertical and horizontal surfaces. Aqueous foam cools hot surfaces by its high water retention ability and must flow freely over a burning liquid surface to form a tough, air- excluding blanket that seals off volatile flammable vapors from access to air or oxygen. Good-quality foam should be dense and long lasting, capable of resisting disruption by wind or draft, stable to intense thermal radiation, and capable of re-sealing in event of mechanical rupture of an established blanket. 1. Aqueous Film Forming Foam (AFFF). These liquid concentrates consist of perfluorinated surfactants(s) with a foam stabilizer and viscosity control agents. The AFFF acts both as a barrier to exclude air or oxygen and, in addition, produces an aqueous film on the fuel surface capable of suppressing the evolution of fuel vapors. Ideally, the foam blanket produced by the AFFF should be of sufficient thickness so as to be visible before fire fighters rely on its effectiveness as a vapor suppressant. 2. Fluoroprotein Foam (FP). Fluoroprotein Foam is simulated foam that is manufactured from protein foam concentrates to which fluorochemical surfactants have been added. This increases the fluidity of the foam and offers a good burn back resistance. The manufacturer of the foam-making equipment should be consulted as to the correct concentrate to be used in any particular system (the proportioners installed must be properly designed and/or set for the concentrate being used). 3. Film Forming Fluoroprotein (FFFP) Foam. These agents are also based on protein foam formulations. They are produced by increasing the quantity and quality of the fluorocarbon surfactants added to the protein hydrolyzate. By doing this, the surface tension of the resulting solution that drains from the expanded foam is reduced to the point that it can spread across the surface of a liquid hydrocarbon fuel. 4. Protein Foam. These liquid concentrates consist primarily of hydrolysis products of various proteinaceous materials. They also contain stabilizing additives and inhibitors to protect against freezing, to prevent corrosion of equipment and containers, to resist bacterial decomposition, to control viscosity, and to assure readiness for use in emergencies. Foam liquids of different types or different manufacturers should not be mixed unless it is determined that they are compatible and/or completely interchangeable. #Supplementary Agents. Supplementary agents are also referred to as secondary agents. Agents that fit into this category are carried on rescue vehicles to handle unique fire fighting requirements most common to airport fire fighting use. Supplementary agents are employed either singly or in combination with foam to accomplish particular aircraft fire fighting operations such as a three dimensional running fuel fires (reference NFPA 403, Annex A, A.5.2 (1)). This class of agents include: • Dry Chemical • Halotron® I • Carbon Dioxide