Water Mist Systems
|Publication Date:||1 November 2012|
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 FM Global Property Loss Prevention Data Sheets. Approval is limited to use in the occupancies described Sections 18.104.22.168 through 22.214.171.124. 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, FM Approvals 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, FM Approvals has determined that water mist systems shall be FM Approved 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. Reference shall be made to the applicable FM Global Data Sheet to determine whether a water mist system is acceptable as supplemental or primary protection. 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 (reference FM Global Datasheet 5-23), 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 combustion turbines in enclosures with volumes not exceeding 2825 ft3 (80 m3), Appendix B. Combustion 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. Consultation with FM Global Property Loss Prevention Data Sheet Number 7-79, Fire Protection for Combustion Turbine Installations, is required for installation of these systems.
This standard states FM Approvals criteria for water mist systems for use as fire control and/or extinguishing systems.
FM Approvals 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 audit program.