NFPA 412-1998 Standard for Evaluating Aircraft Rescue and Fire Fighting Foam Equipment

NFPA 412-1998 Standard for Evaluating Aircraft Rescue and Fire Fighting Foam Equipment. 1-1 Scope. 1-1.1 This standard establishes test procedures for evaluating the foam fire-fighting equipment installed on rescue and fire- fighting vehicles designed in accordance with the applicable portions of NFPA 414, Standard for Aircraft Rescue and Fire Fight- ing Vehicles. 1-2 Purpose. 1-2.1 The tests specified in this standard provide procedures for the evaluation of foam fire-fighting equipment in the field to determine compliance with NFPA 414, Standard for Aircraft Rescue and Fire Fighting Vehicles, and NFPA 403, Standard for Air- craft Rescue and Fire-Fighting Services at Airports. 1-3 Definitions. Foam. An aggregation of small bubbles used to form an air- excluding, vapor-suppressing blanket over the surface of a flammable liquid fuel. Foam, Alcohol-Resistant. Used for fighting fires involving water soluble materials or fuels that are destructive to other types of foams. Some alcohol-resistant foams may be capable of forming a vapor-suppressing aqueous film on the surface of hydrocarbon fuels. Foam, Aqueous Film Forming (AFFF). A concentrated aqueous solution of one or more hydrocarbon or fluorochem- ical surfactants that forms a foam capable of producing a vapor-suppressing aqueous film on the surface of hydrocar- bon fuels. The foam produced from AFFF concentrates is dry- chemical compatible and is therefore suitable for use in com- bination with that agent. Foam Concentrate. A concentrated liquid foaming agent that is mixed with water and air in designated proportions to form foam. Foam Drainage Time (Quarter Life). The time in minutes that it takes for 25 percent of the total liquid contained in the foam sample to drain from the foam. Foam Expansion. The ratio between the volume of foam produced and the volume of solution used in its production. 2-1 Foam and Foam System Tests. 2-1.1 The expansion ratio and 25 percent drainage time are the foam characteristics that shall be determined. Addition- ally, the foam concentration shall be determined, both as a test of the vehicle proportioning system and to establish the legitimacy of the expansion and drainage data obtained. Foam distribution patterns shall be determined for use in calculat- ing the area of fire that the vehicle is capable of controlling. 2-2 Turret Nozzles, Ground Sweep Nozzles, and Hand Hose Line Nozzles. 2-2.1 The foam distribution patterns shall meet the require- ments of NFPA 414, Standard for Aircraft Rescue and Fire Fighting Vehicles, when tested as specified in Section...