NFPA 13
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Transcript of NFPA 13
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NFPA 13-2002 FAQs
NFPA132002FAQs
ResponsestoFAQsarepreparedbyNFPAtechnicalstafftoassistusersinreadingandunderstandingNFPAcodesandstandards.Theresponses,however,arenotFormalInterpretationsissuedpursuanttoNFPARegulations.Anyopinionsexpressedarethepersonalopinionsoftheauthor(s),anddonotnecessarilyrepresenttheofficialpositionoftheNFPAoritsTechnicalCommittees.Inaddition,theresponsesareneitherintended,norshouldbereliedupon,toprovideprofessionalconsultationorservices.
1. DoIneedsprinklersinmybuilding?NFPA13istheNFPAdocumentthatspecifiestheminimumrequirementsfordesigningandinstallingsprinklersystems.Itdoesnotspecifywhichbuildingsrequireasprinklersystem.TherequirementtoinstallasprinklersystemcomplyingwithNFPA13canusuallybefoundinoneofthefollowingsources:buildingcode;federal,stateorlocalregulations;insurer'srequirements;accreditationrequirements;orowner'srequest.
2. IfIhaveadrypipesprinklersystemunderapitchedroofexceedingaslopeof16.7%,doIapplybothareaincreasesfromSection11.2.3.2.4andSection11.2.3.2.5?Yes,bothsectionswouldbeappliedcumulativelytothedesignareachosenfromFigure11.2.3.1.5inaccordancewithSection11.2.3.2.7.Thisisshowninthefollowingexample:TheapplicationareadeterminedfromFigure11.2.3.1.5is1500squarefeet.AsrequiredbySection11.2.3.2.4,1500squarefeetisincreasedby30%to1950squarefeetforthesteeplypitchedroof.AsrequiredbySection11.2.3.2.5,the1950squarefeetisincreasedby30%forthedrypipesystem.Therefore,theoriginaldensitychosenfromFigure11.2.3.1.5mustbeappliedover2535squarefeet.Ensurethattherearenootherdesignareamodificationsrequiredforthesystembeinginstalled
3. CanplasticpipebeusedonasprinklersystemcomplyingwithNFPA13?Section6.3.6allowstheuseofplasticpipethathasbeenspecificallylistedforfireprotectionuse.Thispipemustbeinstalledinaccordancewithitslistinglimitations,includinginstallationinstructions.
4. WhatisthelimitforthecalculatedwatervelocityinasprinklersystemcomplyingwithNFPA13?NFPA13doesnotspecifyamaximumlimitforthecalculatedwatervelocity.
5. Dowalkintypefreezers,coolers,vaultsandsafesrequiresprinklers?Yes.AsexplainedbyA.8.1.1,theseareasrequiresprinklersbecausetheyarepartofthepremises.NFPA13requiresthatsprinklersbeinstalledthroughoutthepremisesinaccordancewithSection4.1.Therearenoexceptionsprovidedwhichallowforsprinkler
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NFPA 13-2002 FAQs
omissionintheseareas.
6. InapplyingtheThreeTimesRule'forsprinklerobstructions(i.e.Section8.6.5.2.1.3),whatdimensionisthe24inchmaximumreferringto?Thismaximumdimensionisthedimensionmeasuredfromthesprinklertothenearestedgeoftheobstruction.Isolatedobstructionsthataremorethan24inchesawayfromstandarduprightandpendentsprinklersdonotgenerallycreateasignificantobstruction.
7. Aresprinklersrequiredinclosets?Yes.TherearelimitedexceptionsspecifiedinSection8.14.8.2forcertainsmallclosetsinthedwellingunitsofhotelsandmotels.
8. Canasupplycontrolvalvebeinstalleddownstreamofthefiredepartmentconnection?TheconfusionthatbringsaboutthisquestionisusuallycausedbySection8.16.2.5.2,Section8.15.1.1.1.3,andSection8.15.1.1.4.2.Thesesectionsarenecessarytodifferentiatethefiredepartmentconnectionfromothertypesofwatersupplies.Normally,acontrolvalveisrequiredbeforeandaftereachcheckvalveinasourceofsupply.Thevalvesarerequiredsothatthecheckvalvecanbeisolatedandserviced.Aswell,acontrolvalveisnormallyrequiredineachautomaticsourceofsupplyinaccordancewithSection8.15.1.1.1.2.However,thesecontrolvalvesarenotnecessary,norallowed,inthefiredepartmentconnectionpiping.Whilethecontrolvalvesarenotallowedinthefiredepartmentconnectionpipingitself,controlvalvescanbeinstalleddownstreamfromthefiredepartmentconnectionpipinginaccordancewith8.15.1.1.Itwouldbeimpracticaltorequireafiredepartmentconnectionafterallcontrolvalvesinamultizoneormultisystemarrangement.Furthermore,Section8.15.1.1.2.1ofNFPA13requiresthatallvalvescontrollingwatersuppliesbesupervisedintheopenposition.Inallcases,thearrangementforthefiredepartmentconnectionmustcomplywithSection8.16.2.4.
9. Ifawatercurtainisinstalled,whatistheequivalentfireseparationrating?NFPA13doesnotspecifyanequivalentfireseparationratingforwatercurtainsinstalledinaccordancewithSection8.14.4.1anddesignedinaccordancewithSection11.2.3.8.
10. Whatistheallowablereductioninfireseparationratingsinabuildingwhereasprinklersystemisinstalled?NFPA13doesnotaddresssuchreductions.Somebuilding/firecodeswillspecifyanallowablereductioninfireseparationratingsforcertainbuildingswheresprinklersareprovidedinaccordancewithNFPA13.Youwouldneedtoconsultwiththeapplicablebuilding/firecodeforyourparticularprojecttodetermineifthereareanyallowablereductions.
11. Aresprinklersrequiredintheupperportionofanarchitecturalceilingfeature,evenwhentherearenoopeningstoaboveandthesprinklersatthelowerportiondonotexceedarea
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NFPA 13-2002 FAQs
ofcoveragelimitations?Thisquestionusuallyariseswitharchitecturalfeaturessuchasskylightsandroomswithmultilevelceilings.Thegeneralconcernwiththesetypesoffeaturesisthepotentialforheattopocket'andthenegativeimpacttotheoperationofthesprinklers.Thiscouldbetrueevenifsprinklersarespacedwithintheirlimitationsforallowableareaofprotection.TheapplicablesectionsofChapter8addressthedistancebelowtheceilingthatsprinklersmustbepositioned.Theneedforsprinklersintheupperportioncanbedeterminedbasedonthedistancefromtheupperleveltothepositionatwhichthesprinklerswouldbeinstalledonthelowerlevel.IfthisdistanceexceedstheallowabledistancesspecifiedinChapter8,thensprinklerswouldberequiredattheupperlevel.ObstructionsspecifiedbyChapter8toanyofthesprinklerswouldalsoneedtobeexaminedandaccountedfor.Section8.6.7andSection8.8.7offerprovisionsthatpermittheomissionofsprinklersintheupperlevelundercertainconditions.WhereSection8.6.7and8.8.7areappropriatelyapplied,thedesignareareductionforquickresponsesprinklerscannotbetakeninaccordancewithItem(4)ofSection11.2.3.2.3.1
12. Aresprinklersrequiredwithinfurniture?No.Sprinklersarerequiredwithinallpermanentspacesofthestructure,suchasclosets,inaccordancewithSection4.1.Moveablefurnitureitems,suchasdesks,dressersandwardrobes,donotrequiresprinklerswithinthemevenwhentheyareaffixedtothepermanentstructureofthebuilding.
13. MustIdesignthesprinklersystemtoprotectthesamehazardthroughoutthestructure?No.NFPA13doesnotrequirethattheentirestructurebeprotectedasasinglehazardclassification.Therearethreeimportantthingstokeepinmind,however,whendesigningasystemwithmultiplehazardclassifications.Thefirstisthatyouwilllockthebuildinguseintothehazardconfigurationthatthesprinklersystemisdesignedfor.Iftheentirespacewasprotectedforthehighesthazard,however,thebuildinguserwouldnothavetoworryaboutthegenerallocationsofthedifferenthazards.Additionally,thehydrauliccalculationprocedureandsystemlayoutbecomemorecomplexwithmultiplehazardclassificationsthanwherethehighesthazardisusedthroughout.Lastly,Section11.1.2specifiesrequirementsforbuildingswithtwoormoreadjacenthazardoccupancies.
14. IftherearenohoseconnectionsinsideabuildingsprinkleredtocomplywithNFPA13,willthewaterdemandneedtoincludeahosestreamallowance?Yes.AnoutsidehosestreamdemandwouldberequiredinaccordancewithSection11.2.3.1.1.
15. IsthereaceilingheightatwhichNFPA13permitstheomissionofsprinklers?No.
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NFPA 13-2002 FAQs
16. DoesNFPA13addressfiresprinklersystemsprotectingstorageabove12feet?Yes.Startingwiththe1999edition,NFPA13incorporatedthefiresprinklersystemdesignandinstallationrequirementsfromNFPA231(StandardforGeneralStorage),NFPA231C(StandardforRackStorageofMaterials),NFPA231D(StandardforStorageofRubberTires),NFPA231E(RecommendedPracticefortheStorageofBaledCotton)andNFPA231F(StandardfortheStorageofRollPaper).TheotherrequirementsofNFPA231,NFPA231C,NFPA231D,NFPA231EandNFPA231FwereincorporatedintoanewstandardNFPA230(StandardfortheFireProtectionofStorage).
17. HowaretheNFPA13designrequirementsarrangedforsystemsprotectingstorageofnormalcombustiblesandplastics?SuchrequirementsarelocatedinaseparatechapterChapter12.AdetailedtableofcontentsforChapter12isasfollows:12.1General12.1.1RoofventsandDraftCurtains12.1.2BuildingHeight12.1.4WetPipeSystems12.1.5AdjacentOccupancies12.1.6DryPipeandPreactionSystems12.1.7CeilingSlope12.1.9ProtectionofIdlePallets12.1.10MiscellaneousStorageandStorageofClassIIVupto12ft12.1.11HighExpansionFoamSystems12.1.12InRackSprinklers12.1.13StorageApplications(Kfactor&density)12.2Palletized,SolidPiled,BinBoxorShelfStorageofClassIIV&Plastic12.2.1General12.2.2ClassIIVCommodities
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NFPA 13-2002 FAQs
12.2.2.1ControlMode(Density/Area)Sprinklers12.2.2.2LargeDrop&SpecificApplicationSprinklers12.2.2.3ESFRSprinklers12.2.2.4SpecialDesignApproaches12.2.3PlasticCommodities12.2.3.1ControlMode(Density/Area)Sprinklers12.2.3.2LargeDrop&SpecificApplicationSprinklers12.2.3.3ESFRSprinklers12.2.3.4SpecialDesignApproaches12.3RackStorageofClassIIV&Plastic12.3.1General12.3.2ClassIIVCommoditiesupto25ft12.3.2.1ControlMode(Density/Area)Sprinklers12.3.2.2LargeDrop&SpecificApplicationSprinklers12.3.2.3ESFRSprinklers12.3.2.4InRackSprinklers12.3.2.5SpecialDesignApproaches12.3.3PlasticCommoditiesupto25ft12.3.3.1ControlMode(Density/Area)Sprinklers12.3.3.2LargeDrop&SpecificApplicationSprinklers12.3.3.3ESFRSprinklers12.3.3.4InRackSprinklers12.3.3.5SpecialDesignApproaches12.3.4ClassIIVCommoditiesover25ft
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NFPA 13-2002 FAQs
12.3.4.1ControlMode(Density/Area)Sprinklers12.3.4.2LargeDrop&SpecificApplicationSprinklers12.3.4.3ESFRSprinklers12.3.4.4InRackSprinklers12.3.4.5SpecialDesignApproaches12.3.5PlasticCommoditiesover25ft12.3.5.1ControlMode(Density/Area)Sprinklers12.3.5.2LargeDrop&SpecificApplicationSprinklers12.3.5.3ESFRSprinklers12.3.5.4InRackSprinklers12.4RubberTireStorage12.5BaledCottonStorage12.6RollPaperStorage12.7SpecialStorage12.7.1PlasticMotorVehicleComponents12.7.2ClassIIV&NonExpandedPlasticsinRetailStores