Viking Foam System is a special system of pipe connected to a source of foam concentrate and to a water supply. The system uses appropriate discharge devices to control and/or extinguish fires which require a smothering and cooling agent. The piping system is connected to the water supply through a control valve that is actuated by operation of automatic detection equipment that is installed in the same areas as the sprinklers. Foam-water systems are designed to distribute a foam-water solution to a specific hazard area for fire protection. Examples: extraction plants, aircraft hangars and areas where flammable-liquid spill fires may occur. Upon exhaustion of the foam concentrate supply, water discharge follows and continues until shut off manually. Systems can be used for discharge of water first, then foam for a specified period, and then followed by water until manually shut off. The type and potential size of the hazard determines the number of discharge devices, type of foam concentrate, and foam-water discharge rate and duration. Characteristics of some flammable products may require higher densities and special foam liquid concentrates. NFPA 11 contains requirements for foam-water systems, with requirements for foam systems also found in NFPA 13, NFPA 16, NFPA 30, NFPA 409, and NFPA 418