NFPA 12-2015 Standard on Carbon Dioxide Extinguishing Systems (Effective Date 12 1 2014).pdf

1、Copyright 2014 National Fire Protection Association. All Rights Reserved.NFPA12Standard onCarbon Dioxide Extinguishing Systems2015 EditionThis edition of NFPA 12, Standard on Carbon Dioxide Extinguishing Systems, was prepared bythe Technical Committee on Gaseous Fire Extinguishing Systems. It was is

2、sued by the Stan-dards Council on November 11, 2014, with an effective date of December 1, 2014, and super-sedes all previous editions.This edition of NFPA 12 was approved as an American National Standard on December 1,2014.Origin and Development of NFPA 12Work on this standard was initiated in 1928

3、 by the Committee on Manufacturing Risks andSpecial Hazards. The standard was first adopted in 1929 and was revised in 1933, 1939, 1940,1941, 1942 (January and May), 1945, 1946, 1948, 1949, 1956, 1957, 1961, 1962, 1963, 1964,1966, 1968, 1972, 1973, 1977, and 1980. Revisions adopted between 1945 and

4、1949 wereproposed by the Committee on Special Extinguishing Systems, and those in 1956 and subse-quent revisions were proposed by the Committee on Carbon Dioxide. The standard wasrevised in 1985 and 1989.The standard was completely rewritten for the 1993 revision to more clearly state therequirement

5、s and to separate the mandatory requirements from the advisory text in an effortto make the document more usable, enforceable, and adoptable.The standard was revised for the 1998 edition and again in 2000 in order to add a newchapter for marine systems.The 2005 edition of this standard was revised w

6、ith a focus on safety.The 2008 edition of the standard was a partial revision.The 2015 edition incorporates a general update of references and other minor improve-ments. In addition, a new system acceptance report has been added to permit compliancewith the commissioning procedures of NFPA 3.121NFPA

7、 and National Fire Protection Association are registered trademarks of the National Fire Protection Association, Quincy, Massachusetts 02169.Technical Committee on Gaseous Fire Extinguishing SystemsJeffrey L. Harrington, ChairHarrington Group, Inc., GA SERonald C. Adcock, SecretaryMarsh Risk Consult

8、ing, AZ IKatherine Adrian, Tyco Fire Suppression preventing a firefrom occurring; extinguishing small fires; or protecting the pub-lic from fire or life safety dangers. 1, 2015.3.3.3 Inspection. A visible examination of a system or portionthereof to verify that it appears to be in operating conditio

9、nand is free of physical damage. 820, 20123.3.4 Lockout. A manually operated valve in the dischargepipe between the nozzles and the supply, which can be lockedin the closed position to prevent flow of carbon dioxide to theprotected area.3.3.5 Maintenance. Work performed to ensure that equip-ment ope

10、rates as directed by the manufacturer.3.3.6 NormallyOccupiedEnclosureorSpace. An enclosure orspace where one or more persons are present under normalcircumstances.3.3.7* Normally Unoccupied Enclosure or Space. An enclo-sure or space not normally occupied but one that could beentered occasionally by

11、one or more persons for brief periods.3.3.8 Occupiable Enclosure or Space. An enclosure or spacethat has dimensions and physical characteristics such that itcould be entered by a person.3.3.9 Pressure.3.3.9.1* High Pressure. Indicates that the carbon dioxide isstored in pressure containers at ambien

12、t temperatures.3.3.9.2* Low Pressure. Indicates that the carbon dioxide isstored in pressure containers at a controlled low tempera-ture of 0F (18C).3.3.10 Standpipe System and Mobile Supply. A system consist-ing of a mobile supply of carbon dioxide, designed to bequickly moved into position and con

13、nected to a system offixed piping, supplying fixed nozzles or hose lines or both thatare designed for either total flooding or local application.126 CARBON DIOXIDE EXTINGUISHING SYSTEMS2015 Edition3.3.11 System.3.3.11.1 Hand Hose Line System. A hose and nozzle assem-bly connected by fixed piping or

14、connected directly to asupply of extinguishing agent. 122, 20153.3.11.2 Local Application System. A system consisting of asupply of extinguishing agent arranged to discharge di-rectly on the burning material.3.3.11.3*Pre-Engineered System. A system that has predeter-mined flow rates, nozzle placemen

15、t, and quantities of car-bon dioxide and that incorporates specific nozzles andmethods of application that can differ from those detailedelsewhere in this standard and those that are listed by atesting laboratory.3.3.11.4 Total Flooding System. A system consisting of a sup-ply of carbon dioxide arra

16、nged to discharge into, and fill tothe proper concentration, an enclosed space or enclosurearound the hazard.3.3.12 Unoccupiable Enclosure or Space. An enclosure orspace that has dimensions and physical characteristics suchthat it could not be entered by a person.3.4 Special Definitions.3.4.1 Marine

17、 Systems. Systems installed on ships, barges, off-shore platforms, motorboats, and pleasure craft.3.4.2 Marine System Spaces.3.4.2.1 Cargo Space. A space for the carriage or storage ofitems or products that are transported by the vessel.3.4.2.2 Electrical Equipment Space. A space containingelectrica

18、l propulsion, power generating, or power distribu-tion equipment.3.4.2.3 Machinery Space. A space that contains mechanicalequipment for handling, pumping, or transferring flam-mable or combustible liquids as a fuel.3.4.2.4 Vehicle Space. A space that is designed for the car-riage of automobiles or o

19、ther self-propelled vehicles.Chapter 4 General Information4.1 Restrictions for Normally Occupied Enclosures.4.1.1 New total flooding carbon dioxide systems shall not beinstalled in normally occupied enclosures except as permittedin 4.1.1.1, 4.1.1.2, 4.1.1.3, 4.1.1.4, or 4.1.1.5.4.1.1.1 New total flo

20、oding carbon dioxide systems shall bepermitted to be installed in normally occupied enclosureswhere it is determined that an inerting concentration is re-quired and the inerting concentration required using alter-nate gaseous agents results in a concentration above the low-est observed adverse effec

21、t level (LOAEL) or the oxygenconcentration is less than 8 percent.4.1.1.2 New total flooding carbon dioxide systems shall bepermitted to be installed in normally occupied enclosures forfires involving energized electrical equipment 400 volts andgrouped electrical cables where no gaseous alternative

22、agenthas been successfully tested.4.1.1.3 New total flooding carbon dioxide systems shall bepermitted to be installed in normally occupied enclosureswhere design methods or hardware, or both, for unenclose-able openings or extended discharge are not available forother gaseous agents.4.1.1.4 New tota

23、l flooding carbon dioxide systems shall bepermitted to be installed in marine cargo holds.4.1.1.5 New total flooding carbon dioxide systems shall bepermitted to be installed in normally occupied enclosures inmarine engine rooms where it is determined that an inertingconcentration is required and the

24、 inerting concentration re-quired using alternate gaseous agents results in a concentra-tion above the LOAEL or the oxygen concentration is lessthan 8 percent.4.1.2 Existing Systems. Existing total flooding carbon dioxidesystems shall be permitted in normally occupied enclosuresequipped with system

25、lockout valves, pneumatic predischargealarms, and pneumatic time delays specified in 4.5.6.4.2 Carbon Dioxide Use and Limitations. See also Annex G.4.2.1* Carbon dioxide fire-extinguishing systems protectingareas where explosive atmospheres could exist shall utilizemetal nozzles, and the entire syst

26、em shall be grounded.4.2.2 In addition, objects exposed to discharge from carbondioxide nozzles shall be grounded to dissipate possible elec-trostatic charges.4.3* Personnel Safety.4.3.1* Hazards to Personnel.4.3.1.1 Consideration shall be given to the possibility of car-bon dioxide drifting and set

27、tling into adjacent places outsidethe protected space. (See 4.3.1.3.)4.3.1.2 Consideration shall also be given to where the carbondioxide can migrate or collect in the event of a discharge froma safety relief device of a storage container.4.3.1.3* In any use of carbon dioxide, consideration shall be

28、given to the possibility that personnel could be trapped in orenter into an atmosphere made hazardous by a carbon diox-ide discharge.4.3.1.3.1 Safeguards shall be provided to ensure promptevacuation, to prevent entry into such atmospheres as de-scribed in 4.3.1.3, and to provide means for prompt res

29、cue ofany trapped personnel.4.3.1.3.2 Personnel training shall be provided.4.3.2 Signs.4.3.2.1 Warning signs shall be affixed in a conspicuous loca-tion in every protected space; at every entrance to protectedspaces; in spaces near the protected spaces where it is deter-mined that carbon dioxide cou

30、ld migrate, creating a hazard topersonnel; and at each entrance to carbon dioxide storagerooms and where carbon dioxide can migrate or collect in theevent of a discharge from a safety device of a storage container.4.3.2.2 The safety sign format, color, letter style of signalwords, message panel lett

31、ering, lettering size, and the safetyprovisions of symbols shall be in accordance with ANSI Z535.4.3.2.3 Safety signs and message wording shall be providedusing a three-panel format as required by 4.3.2.3.1 through4.3.2.3.6.2.4.3.2.3.1 The sign in Figure 4.3.2.3.1 shall be used in everyprotected spa

32、ce.127GENERAL INFORMATION2015 Edition4.3.2.3.2 The sign in Figure 4.3.2.3.2 shall be used at everyentrance to protected space.4.3.2.3.3 The sign in Figure 4.3.2.3.3 shall be used at everyentrance to protected space for systems provided with a win-tergreen odorizer.4.3.2.3.4 The sign in Figure 4.3.2.

33、3.4 shall be used in everynearby space where carbon dioxide could accumulate to haz-ardous levels.4.3.2.3.5 The sign in Figure 4.3.2.3.5 shall be used outsideeach entrance to carbon dioxide storage rooms.4.3.2.3.6 Signs for Manual Operation.4.3.2.3.6.1 Warning signs shall be placed at every location

34、where manual operation of the system could occur.4.3.2.3.6.2 The sign in Figure 4.3.2.3.6.2 shall be used at eachmanual actuation station.4.3.2.4 For installations that have existing signs that differ fromthose required by 4.3.2.3 but that meet the requirements of4.3.2.1, the existing signage shall

35、be considered acceptable if thefacility has a signage training program in place covering all sup-pression systemrelated signage, with all personnel with access toCarbon dioxide gas can cause injury or death.When alarm operates,vacate immediately.WARNINGFIGURE 4.3.2.3.1 Sign in Every Protected Space.

36、Carbon dioxide gas can cause injury or death.When alarm operates,do not enter until ventilated.WARNINGFIGURE4.3.2.3.2 SignatEveryEntrancetoProtectedSpace.Carbon dioxide gas can cause injury or death.When alarm operates orwintergreen scent isdetected, do not enteruntil ventilated.WARNINGFIGURE 4.3.2.

37、3.3 Sign at Every Entrance to Protected Spacefor Systems Provided with a Wintergreen Odorizer.Carbon dioxide gas discharge into nearby space can collect here. When alarm operates, vacate immediately. Carbon dioxide gas can cause injury or death.WARNINGFIGURE4.3.2.3.4 SigninEveryNearbySpaceWhereCarbo

38、nDioxide Could Accumulate to Hazardous Levels.Carbon dioxide gas can cause injury or death.Ventilate the area beforeentering. A high carbondioxide gas concentrationcan occur in this area andcan cause suffocation.WARNINGFIGURE 4.3.2.3.5 Sign Outside Each Entrance to Carbon Di-oxide Storage Rooms.Carb

39、on dioxide gas can cause injury or death.Actuation of this device causes carbon dioxide todischarge. Before actuating,be sure personnel are clearof the area.WARNINGFIGURE 4.3.2.3.6.2 Sign at Each Manual Actuation Station.128 CARBON DIOXIDE EXTINGUISHING SYSTEMS2015 Editionthe protected space either

40、trained on the signage or accompa-nied when in the protected space at all times by a person who hasreceived the training required. New installations in facilities cov-ered by this paragraph shall be equipped with the same type ofsignage as used in existing signage in the facility. All signs withinth

41、e facility shall have the same style and format.4.3.3 Evacuation Procedures.4.3.3.1 All persons who can at any time enter a space pro-tected by carbon dioxide shall be warned of the hazards in-volved and provided with safe evacuation procedures.4.3.3.1.1 Provisions shall be made to prohibit entry of

42、 unpro-tected personnel to spaces made unsafe by a carbon dioxidedischarge until the space is ventilated and appropriate tests ofthe atmosphere have verified that it is safe for unprotectedpersons to enter. Persons who are not properly trained in theuse of and equipped with self-contained breathing

43、apparatus(SCBA) shall not remain in spaces where the concentrationexceeds 4 percent.4.3.3.2 Audible and visible alarms shall be provided in accor-dance with 4.5.6.4.3.3.3* All personnel shall be informed that discharge of car-bon dioxide gas from either high- or low-pressure systems di-rectly at a p

44、erson will endanger the persons safety by causingeye injury, ear injury, or even falls due to loss of balance uponthe impingement of the high-velocity discharging gas.4.3.3.4 A lockout shall be provided on all systems exceptwhere dimensional constraints prevent personnel from enter-ing the protected

45、 space.4.3.3.4.1 Lockout valves shall be installed on all systems wherecarbon dioxide could migrate, creating a hazard to personnel.4.3.3.4.2 In a low-pressure system, the tank shutoff valve shallnot be considered as a lockout valve, except as permitted by4.3.3.4.3.4.3.3.4.3 Where a single low-press

46、ure storage tank suppliessingle or multiple systems protecting interrelated hazards, andwhen none of the hazards require protection if the equipmentbeing protected is shut down, the storage tank shutoff valveshall be permitted to be used as a lockout valve for the entiresystem.4.3.3.4.4* A service d

47、isconnect switch shall not be used as ameans of preventing agent discharge in lieu of a lockout valve.(See 4.5.4.12.)4.3.3.4.5 When maintenance or testing is being conductedon the system, it shall be locked out, or the protected spaceand affected spaces (migration) shall be evacuated.4.3.3.4.6 When

48、protection is to be maintained during thelockout period, a person(s) shall be assigned as a “fire watch”with suitable portable or semiportable fire-fighting equipmentor means to restore protection.4.3.3.4.6.1 The fire watch shall have a communication link toa constantly monitored location.4.3.3.4.6.

49、2 Authorities responsible for continuity of fire pro-tection shall be notified of the lockout and subsequent resto-ration of the system.4.3.3.5* Safe handling procedures shall be followed whentransporting system cylinders.4.3.4 Electrical Clearances.4.3.4.1* All system components shall be located so as to maintainminimum clearances from live parts as shown in Table 4.3.4.1and Figure 4.3.4.1.4.3.4.2* At altitudes in excess of 3300 ft (1000 m), the clear-ance from live parts shall be increased at the rate of 1 percentfor each 330 ft (100 m) increase in altitude above 3300