This standard contains minimum requirements for the design, installation, and maintenance of foam-water sprinkler and spray systems. These systems shall be designed with the required density for either foam or water application as the controlling factor, depending on the design purpose of the system. It is not the intent of this standard to specify where foam-water sprinkler and spray protection is required. The determination of where foam-water sprinklers and spray systems are required shall be made in accordance with such applicable standards as NFPA 30, Flammable and Combustible Liquids Code, and NFPA 409, Standard on Aircraft Hangars. This standard shall apply only to systems using low-expansion foam.