A foam-water system is a special system of pipe connected to a source of foam concentrate and to a water supply. A foam-water system is a special system of pipe connected to a source of foam concentrate and to a water supply.
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 o manually.
Systems can be used for discharge of water first, then foam for a specified period, and then followed by water until manually shut o , 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.