NFPA 16, Standard for the Installation of Foam-Water Sprinkler and Foam-Water Spray Systems, contains minimum requirements for the design, installation, and maintenance of foam-water sprinkler and spray systems. It covers closed head foam sprinkler and open head deluge foam sprinkler and spray systems. These systems are designed for the protection for life and property from fire, with the required foam or water density (gpm/ft2) as the controlling factor, depending on the design purpose of the system. This standard applies only to systems using low-expansion foam. It is not intended to specify where foam-water sprinkler and spray protection is required, only to what degree. Other standards, such as NFPA 30 Flammable and Combustible Liquids Code and NFPA 409 Standard on Aircraft Hangars, specify where protection is to be provided.
To ensure proper system functionality, NFPA 16 requires acceptance testing, performed by qualified personnel meeting the approval of the Authority Having Jurisdiction (AHJ). Acceptance testing assures full protection is provided and is used to determine flow, pressures, actual discharge capacity, foam consumption rate, staffing needs, and other operating characteristics. These tests include either foam discharge from a single system or simultaneous foam discharge from the maximum number of systems expected to operate on a single hazard. A key aspect of this testing is measuring the accuracy of the foam proportioning system through flow testing. The manner in which this is completed is dependent on the type of system. Generally, foam concentrates injected into the water are required to be within 0 to plus 30% of the manufacturer’s listed concentration, or plus 1 percentage point, whichever is less. It is emphasized that full flow testing of the proportioning system and discharge devices are required. The rate of foam solution discharge is calculated using the recorded inlet pressure, end-of-system pressure, or both. In performing system tests, the standard requires that users must collect and dispose of the discharged foam solution in accordance with the AHJ requirements. When approved, alternative test systems are permitted to be substituted for actual foam concentrate.
NFPA 25, Standard for the Inspection, Test and Maintenance of Water-Based Fire Protection Systems, is referenced by NFPA 16 and provides additional requirements on foam system inspection and test requirements.