scope:

This standard encompasses the design and performance requirements for water mist systems for use as fire control and/or extinguishing systems designed and installed per the manufacturers design and installation manual, requirements of applicable national or international standards and the requirements of the authority having jurisdiction. Certification is limited to use in the occupancies described Sections 1.2.3.1 through 1.2.3.15. Due to the current state of water mist system technology, a comprehensive absolute standard for the testing of water mist system components is not possible. Since each water mist system is unique in its operation and design, the component testing of the water mist system shall be performed on a case-by-case basis. The component testing section is intended to be used as a guideline for the manufacturer as to the scope of the test program that can be expected. Upon request for a program, and appropriate system documentation, the certification agency will prepare a customized evaluation program for the specific water mist system. While customization of the component testing is necessary, the fire test protocols are generic and required for all water mist systems. The manufacturer's design calculations, stated performance requirements, as well as component functionality and reliability will be verified.

This standard is intended to verify that the product described will meet stated conditions of performance, safety and quality useful to the ends of property conservation.

Since water mist is an evolving technology water mist systems shall be certified for the protection of specific applications and specific protected area volumes. Extrapolation beyond the volumes which were tested is not permitted except where explicitly noted. The scope of this standard encompasses the following occupancy protection applications:

Protection of machinery in enclosures with volumes not exceeding 2825 ft³ (80 m³), Appendix A. This application includes enclosures with machinery such as internal combustion engines (excluding engine test cells), oil pumps, oil tanks, fuel filters, generators, transformer vaults, gear boxes, drive shafts, lubrication skids, diesel engine driven generators, and other similar equipment using liquid hydrocarbon fuel and/or hydraulic, heat transfer, and lubrication fluids with volatilities less than or equal to heptane; enclosures with incidental use or storage of hydrocarbon ignitable liquids (also known as flammable liquids) of not more than two 55 gal (208 L) drums. All hazards included under the scope of this total compartment application shall be protected for a minimum of twice the longest time to extinguish the test fires, time to shut down process equipment, or 10 minutes, whichever is greater.

Protection of gas turbines in enclosures with volumes not exceeding 2825 ft³ (80 m³), Appendix B. Gas turbines included under the scope of this total compartment application shall be protected for a minimum of twice the longest time to extinguish the test fires, turbine rundown time (including the time that the turbine surfaces are above the auto-ignition temperature of the lubricating fluid), the time to shut down process equipment, or 10 minutes, whichever is greater.

Protection of machinery in enclosures with volumes not exceeding 9175 ft³ (260 m³), Appendix C. This application includes rooms with machinery such as internal combustion engines (excluding engine test cells), oil pumps, oil tanks, fuel filters, generators, transformer vaults, gear boxes, drive shafts, lubrication skids, diesel engine driven generators, and other similar machinery using fuel and/or lubrication fluids with volatilities less than or equal to heptane. All hazards included under the scope of this total compartment application shall be protected for a minimum of twice the longest time to extinguish the test fires, the time to shut down process equipment, or 10 minutes, whichever is greater.

Protection of gas turbines in enclosures with volumes not exceeding 9175 ft³ (260 m³), Appendix D. Gas turbines included under the scope of this total compartment application shall be protected for a minimum of twice the longest time to extinguish the test fires, turbine rundown time (including the time that the turbine surfaces are above the auto-ignition temperature of the lubricating fluid), the time to shut down process equipment, or 10 minutes, whichever is greater.

Protection of machinery in enclosures with volumes exceeding 9175 ft³ (260 m³), Appendix E. This application includes enclosures with machinery such as internal combustion engines (excluding engine test cells), oil pumps, oil tanks, fuel filters, generators, transformer vaults, gear boxes, drive shafts, lubrication skids, diesel engine driven generators, and other similar equipment using liquid hydrocarbon fuel and/or hydraulic, heat transfer, and lubrication fluids with volatility less than or equal to heptane; enclosures with incidental use or storage of hydrocarbon ignitable liquids (also known as flammable liquids) of not more than two 55 gal (208 L) drums. All hazards included under the scope of this total compartment application shall be protected for a minimum of twice the longest time to extinguish the test fires, the time to shut down process equipment, or 10 minutes, whichever is greater.

Protection of gas turbines in enclosures with volumes exceeding 9175 ft³ (260 m³), Appendix F. Gas turbines included under the scope of this total compartment application shall be protected for a minimum of twice the longest time to extinguish the test fires, the turbine rundown time (including the time that the turbine surfaces are above the auto-ignition temperature of the lubricating fluid), the time to shut down process equipment, or 10 minutes, whichever is greater. For primary protection consideration, see Section 1.9, Definitions, "Primary Protection".

Protection of Non-Storage Occupancies, Hazard Category 1 (HC-1), Appendix G. Protection of Non-Storage Occupancies, Hazard Category 2 (HC-2) and Non-Storage Occupancies, Hazard Category 3 (HC-3) are covered in Section 1.2.3.15. The occupancies are defined as Hazard Category 1 (HC-1). The applications are currently limited to ceiling heights of 8 ft (2.4 m) for restricted areas and 16 ft 5 in. (5 m) for unrestricted areas (refer to Section 1.9, Definitions, "Light Hazard Occupancy," for specific descriptions of restricted and unrestricted areas). The water supply shall be capable of supplying 60 minutes of water to the hydraulically most remote nine automatic nozzles or all automatic nozzles within a 1,500 ft² (140 m²) demand area, whichever is greater, for systems Approved for the protection of unrestricted areas. For installations with less than 1500 ft² (140 m²) in area, the water supply shall be capable of supplying 60 minutes of water to all nozzles in the protected area. For systems Approved for the protection of restricted areas, the water supply shall be capable of supplying 60 minutes of water to all automatic nozzles within the compartment.

Protection of wet benches and other similar processing equipment, Appendix H. This application includes tools which consist of ventilated and unventilated compartments, spin rinse dryers, alcohol vapor dryers, chemical and mechanical polishing tools, and step and repeat exposure systems. All hazards included under the scope of this local application shall be protected for a minimum of 2 minutes or twice the longest time to extinguish the worst case fire scenario, whichever is greater. Time delays are limited to 30 seconds, unless tested for a longer time duration.

Protection of local application occupancies, Appendix I. Water mist systems which successfully pass the fire scenarios described in Appendix I shall be limited to the protection of the following applications:

A. Ignitable liquid (also known as flammable liquid) pool fires where the liquid release can be confined to a diked area. The entire surface of the diked area shall be protected by the water mist system.

B. Ignitable liquid (also known as flammable liquid) channel fires in channels not exceeding the water mist system manufacturer's maximum specified width and with no limit to channel length.

C. Partially obstructed ignitable liquid (also known as flammable liquid) pool fires where the percentage of obstructed surface is limited to that tested.

D. Spray fires up to 6 MW fueled by ignitable liquid (also known as flammable liquid).

E. Spray and pool fire combinations where the release can be confined to a diked area.

F. Ignitable liquid (also known as flammable liquid) residues (ink and paper dust) on printing presses.

Applicants desiring to protect special hazard equipment with ignitable liquids (also known as flammable liquids) with volatilities less than or equal to that of heptane will need to conduct the fire scenarios described in Appendix I, substituting heptane for diesel as the test fuel where appropriate. All hazards shall be protected for a minimum of twice the longest time to extinguish the test fires, time to shut down process equipment, or 10 minutes, whichever is greater.

Protection of industrial oil cookers, Appendix J. Application of the water mist system is limited to the protection of the industrial oil cookers only, and does not include the protection of other equipment such as exhaust ducts, heaters, heat exchangers, and food processing areas, unless tested for these applications. Consideration of the application and use of nozzle protection caps to prevent or reduce the amount of nozzle contamination should be given and the use of such caps should be included in the fire test and nozzle performance test requirement programs. This local application does not include the protection of other equipment such as exhaust air ducts, heaters, heat exchangers, and food processing or food preparation areas.

Industrial oil cookers are typically non-insulated conveyorized fryers, or occasional batch kettles, used in food processing plants for chicken, fish, potato products (e.g., fries/chips), doughnuts and many other food products. These cookers are extremely different in size, configuration, and construction from standard kitchen or restaurant oil cookers or fryers and require a different type of extinguishment system.

Industrial oil cookers normally have large cooking surfaces, from 50 ft² (4.6 m²) to several hundred square feet. They contain from several hundred gallons up to approximately 5000 gallons (18900 L) of cooking oil. Industrial oil cookers (except for some batch kettles) typically have moveable covers, or hoods, that may be hydraulically operated.

The hood is generally in a closed position during a normal operation period. However, the hood may be occasionally opened for routine maintenance. There are also exhaust stacks connected on top of the hood.

The most severe fire incident involving industrial oil cookers is a fire caused by overheating the cooking oil until it reaches its auto-ignition temperature (AIT). Installation of an interlocking system to prevent the oil from reaching its AIT is a normal practice in the industry. However, the AIT fire may still occur due to a system malfunction or simple human error. Thus, all the performance tests proposed in this document require extinguishment of an AIT fire. The AIT fire is particularly challenging because of its rapid spread of flame over the oil surface and its difficulty in extinguishment, as it requires flame extinction over the entire surface with simultaneous rapid cooling to prevent re-ignition.

Exhaust air fans should be interlocked to automatically shutdown upon fire detection or operation of the water mist system. Exhaust duct protection should be specified in the manufacturer's design, installation, operation and maintenance manual. (Note: Water spray protection for the ducts is required if operation of the duct system during water mist system discharge is necessary. Automatic sprinkler protection is recognized as an effective alternative to water spray.)

Commonly used cooking oils, their flash points, and AITs are listed in Table 1.2.3.10 as a reference only. Canola oil is considered a representative vegetable oil and may be used as the testing medium in the Appendix J fire tests. Canola oil has a nominal density equal to 7.8 lb/gal (0.93 kg/L) and nominal specific heat equal to 0.59 BTU/lb·°F (2.5 kJ/kg·°C). Alternative cooking oils may be used based on the manufacturer's intended applications for protection, and certification shall be limited to cooking oils with flash points and AITs less than or equal to the tested oil.

The agent supply shall be capable of supplying agent to all open nozzles at the maximum rated operating pressure for a minimum of twice the total time needed to extinguish the worst case fire scenario and subsequently cool the oil to a temperature below its flash point, as established by testing in accordance with Appendix J, or 10 minutes, whichever is greater.

Protection of continuous wood board presses, Appendix K. Application of the water mist system is limited to the protection of the continuous wood board press only, and does not include the protection of other equipment unless tested for other applications. All hazards included under the scope of this application shall be protected for a minimum of twice the longest time to extinguish the test fires or 30 minutes, whichever is greater.

Protection of ventilated bench-top chemical fume laboratory hoods or enclosures using ignitable liquids, Appendix L. A fire that initiates within a fume hood or enclosure can quickly spread, particularly where there is appreciable use of solvents and/or combustibles, and result in extensive damage to the laboratory and surrounding area. The installation of an integrated water mist system provides an enhanced fire protection strategy to the automatic sprinkler system that can maximize loss prevention and minimize business interruption.

Protection of data center processing equipment rooms/halls which include control rooms, process control rooms, diagnostic equipment, and critical systems and equipment associated with data centers, Appendix M and N. Forced ventilation is included in the evaluation to a maximum nominal upward velocity of 3.3 ft/s (1 m/s) through perforated floor openings and a maximum 4 ft/sec (1.2 m/s) horizontal airflow from server cabinets. Preaction systems are limited to single interlock configurations with a maximum 30 second water delivery time delay.

For above raised floor protection the water supply shall be capable of supplying 60 minutes of water to the hydraulically most remote nozzles. The design area of the water mist system shall be 6 nozzles or 1.5 times the number of operated nozzles during fire performance testing, whichever is greater. For below raised floor protection the water supply shall be capable of supplying 60 minutes of water to the hydraulically most remote nozzles. The design area of the water mist system shall be a minimum of 6 nozzles for an area of coverage design and a minimum of 4 nozzles for a local application design. For an installation including both above and below raised floor protection the design area of the water mist system shall be based on the most hydraulically demanding protection.

The systems are for the protection of data and power cables with a maximum Fire Propagating Index (FPI) of 26 in the metric unit when tested in accordance with FM Approvals Examination Standard Class 3972, Test Standard for Cable Fire Propagation. Alternative cables with a higher FPI may be used based on the manufacturer's intended applications for protection, and certification shall be limited to cables FPIs less than or equal to the tested cable. The systems are not intended to protect data processing equipment with packaging awaiting installation. Packaged equipment is to be located in storage and staging areas separate from data processing equipment rooms (i.e., where fire involving the storage will not expose critical equipment). Where storage and staging areas are not available, limit in-process packaged equipment in data processing equipment rooms to a temporary basis with regular removal of the packaging during the installation.

The systems are tested and listed to provide primary protection of the occupancy. The systems have been proven to extinguish fire involving cables but are not intended to provide equipment protection.

Protection of machinery in enclosures with volumes exceeding 9175 ft³ (260 m³) and protection of gas turbines in enclosures with volumes exceeding 9175 ft³ (260 m³), Appendix O. The ½-scale fire performance testing described in Appendix O can be conducted as an option to the full-scale fire performance testing described in Appendix E and/or Appendix F. Reference Section 1.2.3.5 and 1.2.3.6 for information on the applications under the scope of Appendix E and Appendix F.

Protection of Non-Storage Occupancies, Hazard Category 2 (HC-2) and Hazard Category 3 (HC-3), Appendix P. Protection of Non-Storage Occupancies, Hazard Category 1 (HC-1) are covered under Section 1.2.3.7. The occupancies are defined as Hazard Category 2 (HC-2) and Hazard Category 3 (HC-3). The water supply shall be capable of supplying 60 minutes of water to the hydraulically most remote nine automatic nozzles, or 1.5 times the number of operated nozzles during fire performance testing, whichever is greater. Water mist systems with certification for HC-3 are suitable for HC-3, HC-2, and HC-1. Water mist systems with certification for HC-2 are suitable for HC-2 and HC-1. Water mist systems with certification for HC-1 are only suitable for HC-1 (see Section 1.2.3.7).

Protection of other occupancies, Appendix Q. Manufacturers interested in pursuing water mist system fire protection of other occupancies or hazards are invited to request, in writing, a detailed description of the desired occupancy and proposed fire protection water mist system. Appropriate system component and fire test performance requirements may then be jointly developed. Suggested occupancies are as listed in Appendix P.

Purpose

This standard states testing and certification requirements for water mist systems for use as fire control and/or extinguishing systems.

Testing and certification criteria may include, but are not limited to, component, system and fire testing performance requirements, marking requirements, examination of manufacturing facility(ies), audit of quality assurance procedures, and a surveillance program.