NFPA 13, 2002 Edition - · PDF fileNFPA 13, 2002 Edition Seismic Design for Fire Sprinkler ......

NFPA 13, 2002 EditionNFPA 13, 2002 EditionSeismic DesignSeismic Design

forforFire Sprinkler SystemsFire Sprinkler Systems

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SpeakerSpeakerSteven Scandaliato, S.E.T.Steven Scandaliato, S.E.T.Scandaliato Design GroupScandaliato Design Group12354 W. Alameda Pkwy., Ste. 170 12354 W. Alameda Pkwy., Ste. 170 •• Lakewood, CO 80228 Lakewood, CO 80228Ph: (303) 985-3300Ph: (303) 985-3300 •• Email: steven@ Email: [email protected]

Steven is a principal partner with Scandaliato Design Group, Inc. and aNICET IV Certified Senior Engineering Technician. He has over 19 yearsexperience in fire protection design, covering all types of active andpassive life safety systems. Steven has also been involved at everylevel of construction project management and engineering systemdesign. He serves on the Technical Advisory Committee for theAmerican Fire Sprinkler Association and is a member of the NFPA 13and 5000/101 Committees. Steven has become a nationallyrecognized speaker on fire suppression system design and engineering.He is published in several periodicals including articles for the NFPAJournal and Fire Marshals Quarterly and is currently a contributingauthor to the new text being published by NFPA/SFPE entitled,“Sprinkler Design For Engineers”. Over the last 10 years, he hasinstructed thousands in contracting and professional associationsincluding the American Fire Sprinkler Association, AIA, Society of FireProtection Engineers, American Society of Plumbing Engineers and theInternational Fire Marshals Associations across the country. He is amember of NFPA, SFPE and AFSA.

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AgendaAgenda

νν Seismic Design for AutomaticSeismic Design for AutomaticSprinkler SystemsSprinkler Systems

νν Seismic Design and the CodesSeismic Design and the Codesνν Seismic Design and Shop DrawingsSeismic Design and Shop Drawingsνν Seismic Design and StructuralSeismic Design and Structural

ApplicationsApplicationsνν Practice ExamplePractice Example

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Seismic Design for Sprinkler SystemsSeismic Design for Sprinkler Systems

νν Automatic Sprinkler SystemsAutomatic Sprinkler Systemsνν History and DevelopmentHistory and Development

νν Committee Comments on EQ BracingCommittee Comments on EQ Bracing

νν Theory and Purpose for EQ BracingTheory and Purpose for EQ Bracing

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νν Automatic Sprinkler SystemsAutomatic Sprinkler Systemsνν History and DevelopmentHistory and Development

1. Guidance was first included in NFPA in 19471. Guidance was first included in NFPA in 19472. Major modifications following the San Fernando2. Major modifications following the San Fernando quake in 1971, the Loma quake in 1971, the Loma Prieta Prieta in 1989 and thein 1989 and the Northridge in 1994 Northridge in 19943. Most of the criteria is found in Chapter 9-3 and the3. Most of the criteria is found in Chapter 9-3 and the appendix. appendix.4. New federal acts and requirements that have been4. New federal acts and requirements that have been enacted enacted

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νν Automatic Sprinkler SystemsAutomatic Sprinkler Systemsνν Purpose for Earthquake BracingPurpose for Earthquake BracingOverall objective of NFPA 13 to Prevent Damage.Overall objective of NFPA 13 to Prevent Damage.

11 Minimize stresses in piping that would result in damageMinimize stresses in piping that would result in damageby providing flexibility and clearances at points whereby providing flexibility and clearances at points wherethe building is expected to move during an earthquake.the building is expected to move during an earthquake.

22 Minimize damaging forces by keeping the piping fairlyMinimize damaging forces by keeping the piping fairlyrigid when supported from a building componentrigid when supported from a building componentexpected to move as a unit during an earthquake; suchexpected to move as a unit during an earthquake; suchas a floor/ceiling assembly.as a floor/ceiling assembly.

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Seismic Issues for Sprinkler SystemsSeismic Issues for Sprinkler Systems

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νν Automatic Sprinkler SystemsAutomatic Sprinkler Systemsνν Committee Comments from NFPACommittee Comments from NFPA and Factory Mutual and Factory Mutual

1. See sections 9-3 of the NFPA 13 Handbook1. See sections 9-3 of the NFPA 13 Handbook2. Common sources of water damage were broken2. Common sources of water damage were brokenor separated overhead sprinkler piping, brokenor separated overhead sprinkler piping, brokensprinklerssprinklersdue to impact with nearby structural members ordue to impact with nearby structural members orother equipment, broken sprinklers or pipe dropsother equipment, broken sprinklers or pipe dropsdue todue toexcessive differential movement between excessive differential movement between unbracedunbracedsuspended ceilings and the pipe drops, and brokensuspended ceilings and the pipe drops, and brokenin-rack sprinkler system piping or sprinklers due toin-rack sprinkler system piping or sprinklers due toexcessive rack movement.excessive rack movement.

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3. In addition to damage from water leakage, fire3. In addition to damage from water leakage, fireprotection systems are often impaired due to directprotection systems are often impaired due to directdamage to the systems, or due to damagedamage to the systems, or due to damageto public water supplies or utilities needed for fireto public water supplies or utilities needed for fireprotection. Significant impairments to fire protectionprotection. Significant impairments to fire protectionsystems may expose a facility to a severe fire losssystems may expose a facility to a severe fire lossfollowing an earthquake.following an earthquake.

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In evaluating the many incidents of damage, twoIn evaluating the many incidents of damage, twoconclusions are very apparent:conclusions are very apparent:1. Only by providing in a systematic manner the1. Only by providing in a systematic manner thenecessary features which incorporate necessary features which incorporate swayswaybracingbracing,,flexibilityflexibility, , clearancesclearances and and anchorageanchorage where whereneeded can a fire protection system beneeded can a fire protection system beadequatelyadequatelyprotected to mitigate potential damage fromprotected to mitigate potential damage fromearthquakes.earthquakes.

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In evaluating the many incidents of damage, twoIn evaluating the many incidents of damage, twoconclusions are very apparent:conclusions are very apparent:2. Omission of only a few of the critical2. Omission of only a few of the criticalcomponents necessary for adequate earthquakecomponents necessary for adequate earthquakeprotectionprotectionmay create conditions where significantmay create conditions where significantearthquake damage may result in substantialearthquake damage may result in substantialwater damage.water damage.The necessary shutdown of the system to stopThe necessary shutdown of the system to stopfurther damage also creates a fire protectionfurther damage also creates a fire protectionsystemsystemimpairment.impairment.

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νν CodesCodesνν Fire CodesFire Codes

1. UFC1. UFC

2. IFC2. IFC

3. NFPA3. NFPA

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νν CodesCodesνν Building CodesBuilding Codes

1. UBC1. UBC

2. IBC2. IBC

3. NFPA (5000)3. NFPA (5000)

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1. IBC 1614: Earthquake Loads 1. IBC 1614: Earthquake Loads –– General GeneralEvery structure, and portion thereof, shall as aEvery structure, and portion thereof, shall as a

minimum, be designed and constructed to resist theminimum, be designed and constructed to resist theeffects of earthquake motions and assigned aeffects of earthquake motions and assigned aseismic design category as set forth in Sectionseismic design category as set forth in Section1616.3. Structure determined to be in Seismic1616.3. Structure determined to be in SeismicDesign Category Design Category ‘‘AA’’ need only comply with Section need only comply with Section1616.4 (structural components only).1616.4 (structural components only).

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Two exceptions exempting sprinkler systems fromTwo exceptions exempting sprinkler systems fromearthquake protection.earthquake protection.

1. Very low ground acceleration (mapped)1. Very low ground acceleration (mapped)

2. Building falls into Seismic Design Category2. Building falls into Seismic Design CategoryA or B which can only be determined after step byA or B which can only be determined after step bystep evaluation.step evaluation.

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6 Exceptions:6 Exceptions:1. Structures designed in accordance with1. Structures designed in accordance with

provisions from ASCE 7 are permitted.provisions from ASCE 7 are permitted.2. Detached on and two family dwellings per2. Detached on and two family dwellings per

Section 101.2 in Seismic Design Categories A, BSection 101.2 in Seismic Design Categories A, Band C or located where the mapped short-periodand C or located where the mapped short-periodspectral response acceleration, Ss is less than 0.4gspectral response acceleration, Ss is less than 0.4gare exempt from the requirements of Sections 1613are exempt from the requirements of Sections 1613through 1622.through 1622.

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6 Exceptions: 6 Exceptions: concon’’tt..3. The seismic-force-resisting system of wood3. The seismic-force-resisting system of wood

frame buildings that conform to the provisions offrame buildings that conform to the provisions ofSection 2308 are not required to be analyzed asSection 2308 are not required to be analyzed asspecified in Section 1616.1.specified in Section 1616.1.

4. Agricultural storage structures intended only4. Agricultural storage structures intended onlyfor incidental human occupancy are exempt fromfor incidental human occupancy are exempt fromthe requirements of Sections 1613 through 1623.the requirements of Sections 1613 through 1623.

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6 Exceptions: 6 Exceptions: concon’’tt..5. Structures located where 5. Structures located where ““mappedmapped”” short- short-

period spectral response acceleration, Speriod spectral response acceleration, Ss,s,determined in accordance with Section 1615.1 isdetermined in accordance with Section 1615.1 isless than or equal to 0.15g and where the less than or equal to 0.15g and where the ““mappedmapped””spectral response acceleration at 1-second periodspectral response acceleration at 1-second periodSS11 determined in accordance with Section 1615.1 is determined in accordance with Section 1615.1 isless than or equal to 0.04g shall be categorized asless than or equal to 0.04g shall be categorized asSeismic Design Category A. Seismic DesignSeismic Design Category A. Seismic DesignCategory A structures need only comply withCategory A structures need only comply withSection 1616.4.Section 1616.4.

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6 Exceptions: 6 Exceptions: concon’’tt..6. Structures located where the short-period6. Structures located where the short-period

““designdesign”” spectral response acceleration, S spectral response acceleration, Ss,s,determined in accordance with Section 1615.1 isdetermined in accordance with Section 1615.1 isless than or equal to 0.167g and the less than or equal to 0.167g and the ““designdesign””spectral response acceleration at 1-second periodspectral response acceleration at 1-second periodSS11 determined in accordance with Section 1615.1 is determined in accordance with Section 1615.1 isless than or equal to 0.04g shall be categorized asless than or equal to 0.04g shall be categorized asSeismic Design Category A. Seismic DesignSeismic Design Category A. Seismic DesignCategory A structures need only comply withCategory A structures need only comply withSection 1616.4.Section 1616.4.

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νν CodesCodesνν Special RequirementsSpecial Requirements

1. Factory Mutual1. Factory Mutual

2. Federal Government (DOD, DOE, DOT, COE)2. Federal Government (DOD, DOE, DOT, COE)

3. State & Local AHJ3. State & Local AHJ

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νν Shop DrawingsShop Drawingsνν NFPA Text (Chapter 9.3 NFPA Text (Chapter 9.3 ‘‘02ed)02ed)

1. Couplings1. Couplings

2. Separation2. Separation

3. Clearance3. Clearance

4. Sway Bracing4. Sway Bracing

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Couplings - Section 9.3.1.1 & .2 Couplings - Section 9.3.1.1 & .2New section added to 2002.New section added to 2002..1 .1 9.3 does not tell you when it is required. It tells 9.3 does not tell you when it is required. It tells you that when required HOW to design and install it.you that when required HOW to design and install it..2.2 System may be excempted if a PE proves that the System may be excempted if a PE proves that the systems performance with regard to seismic forces will besystems performance with regard to seismic forces will beequal to or greater than that of the equal to or greater than that of the building that it is installedbuilding that it is installedin.in.

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Couplings - Section 9.3.2 Couplings - Section 9.3.2Listed flexible pipe couplings joining groovedListed flexible pipe couplings joining grooved

end pipe shall be provided as flexure joints toend pipe shall be provided as flexure joints toallow individual sections of piping 2 1/2allow individual sections of piping 2 1/2”” (64 mm) (64 mm)or larger to move differentially with the individualor larger to move differentially with the individualsections of the building to which it is attached. sections of the building to which it is attached.

(Continued)(Continued)

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Couplings - Section 9.3.2 Couplings - Section 9.3.2Couplings shall be arranged to coincide withCouplings shall be arranged to coincide withstructural separations within a building. structural separations within a building. SystemsSystemshaving more flexible couplings than requiredhaving more flexible couplings than requiredhere shall be provided with additional swayhere shall be provided with additional swaybracing as required in 9-3.5.3.6. The flexiblebracing as required in 9-3.5.3.6. The flexiblecouplings shall be installed as follows:couplings shall be installed as follows:

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((1) Within 24 in. (610 mm) of the top and bottom of all1) Within 24 in. (610 mm) of the top and bottom of allrisers.risers.

Exception No.1: In risers less than 3 ft. (0.9 m) inException No.1: In risers less than 3 ft. (0.9 m) inlength, flexible couplings are permitted to belength, flexible couplings are permitted to beomitted.omitted.Exception No.2: In risers 3 to 7 ft. (0.9 to 2.1 m) inException No.2: In risers 3 to 7 ft. (0.9 to 2.1 m) inlength, one flexible coupling is adequate.length, one flexible coupling is adequate.

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(2) *Within 12 in. (305 mm) above and within 24 in. below the floor(2) *Within 12 in. (305 mm) above and within 24 in. below the floorin multistory buildings. When the flexible coupling below the floorin multistory buildings. When the flexible coupling below the flooris above the tie-in main to the main supplying the floor, a flexibleis above the tie-in main to the main supplying the floor, a flexiblecoupling shall be provided on the vertical portion of the tie-incoupling shall be provided on the vertical portion of the tie-inpiping.piping.

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(3) On both sides of concrete or masonry walls(3) On both sides of concrete or masonry wallswithin 1 ft. of the wall surface. Unless within 1 ft. of the wall surface. Unless clearanceclearancearound the pipe is provided in accordance with 9-around the pipe is provided in accordance with 9-3.4.3.4.

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(4) Within 24 in. of building expansion joints.(4) Within 24 in. of building expansion joints.(5) Within 24 in. (610 mm) of the top and bottom of drops to(5) Within 24 in. (610 mm) of the top and bottom of drops to

hose lines, rack sprinklers and mezzanines, regardless ofhose lines, rack sprinklers and mezzanines, regardless ofpipe size.pipe size.

(6) Within 24 in. (610 mm) of the top of drops exceeding 15 ft.(6) Within 24 in. (610 mm) of the top of drops exceeding 15 ft.(4.6 m) in length to portions of systems supplying more than(4.6 m) in length to portions of systems supplying more thanone sprinkler, regardless of pipe size.one sprinkler, regardless of pipe size.

(7) Above and below any intermediate points of support for a(7) Above and below any intermediate points of support for ariser or other vertical pipe.riser or other vertical pipe.

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Separation - Section 9.3.3 Separation - Section 9.3.3Seismic separation assemblies with flexibleSeismic separation assemblies with flexiblefittings shall be installed where sprinkler piping,fittings shall be installed where sprinkler piping,regardless of size,crosses building seismicregardless of size,crosses building seismicseparation joints above ground level.separation joints above ground level.

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Nice try!

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Clearance - Section 9.3.4 Clearance - Section 9.3.4Clearance shall be provided around all pipingClearance shall be provided around all pipingextending through walls, floors, platforms, andextending through walls, floors, platforms, andfoundations, including drains, fire departmentfoundations, including drains, fire departmentconnections, and other auxiliary pipingconnections, and other auxiliary piping

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9.3.4.5 (New 9.3.4.5 (New –– incorporated exceptions) If you do incorporated exceptions) If you donot meet at least one of the following sections, thennot meet at least one of the following sections, thenyou must provide a hole that is a minimum of 2you must provide a hole that is a minimum of 2””(nominal) larger than the pipe for pipe sizes 1(nominal) larger than the pipe for pipe sizes 1”” - 3 - 3_”_”and 4and 4”” (nominal) larger than the pipe for pipe sizes 4 (nominal) larger than the pipe for pipe sizes 4””and larger.and larger.

Example: A 2Example: A 2”” pipe will require a 4 pipe will require a 4”” hole. hole. A 4 A 4”” pipe will require a 8 pipe will require a 8”” hole. hole.

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Flexiblecplg

Rigidcplgs

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Sway Bracing - Section 9.3.5Sway Bracing - Section 9.3.5

9.3.5.1.1 The system piping shall be braced to resist9.3.5.1.1 The system piping shall be braced to resistboth lateral and longitudinal seismic loads and toboth lateral and longitudinal seismic loads and toprevent vertical motion resulting from seismic loads.prevent vertical motion resulting from seismic loads.The structural components to which bracing isThe structural components to which bracing isattached shall be determined to be capable ofattached shall be determined to be capable ofcarrying the added applied seismic loads.carrying the added applied seismic loads.

9.3.5.2.1 Sway braces shall be designed to9.3.5.2.1 Sway braces shall be designed towithstand forces in tension and compression.withstand forces in tension and compression.

9.3.5.2.2.* Tension only bracing systems shall be9.3.5.2.2.* Tension only bracing systems shall bepermitted for use where listed for this service andpermitted for use where listed for this service andwhere installed in accordance with their listingwhere installed in accordance with their listinglimitations, including installation instructions.limitations, including installation instructions.

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Sway Bracing Sway Bracing 6-4.56-4.5

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Sway Bracing Sway Bracing 6-6-4.54.5

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Seismic Design for Sprinkler SystemsSeismic Design for Sprinkler Systems9.3.5.3.19.3.5.3.1 Lateral sway bracing spaced at a Lateral sway bracing spaced at amaximum interval of 40 ft. (12.2 m) on center shallmaximum interval of 40 ft. (12.2 m) on center shallbe provided on all feed and cross mains be provided on all feed and cross mains regardlessregardlessof size and all branch lines and other piping with aof size and all branch lines and other piping with adiameter of diameter of 2 1/22 1/2 in. (63.5 mm) and larger. in. (63.5 mm) and larger.9.3.5.3.29.3.5.3.2 The distance between the last brace and The distance between the last brace andthe end of the pipe shall not exceed 20 ft. (6.1 m).the end of the pipe shall not exceed 20 ft. (6.1 m).This requirement shall not preclude the use of aThis requirement shall not preclude the use of alateral brace serving as a longitudinal brace aslateral brace serving as a longitudinal brace asdescribed in this paragraph.described in this paragraph.9.3.5.3.49.3.5.3.4 The last length of pipe at the end of a feed The last length of pipe at the end of a feedor cross main shall be provided with a lateral brace.or cross main shall be provided with a lateral brace.9.3.5.3.59.3.5.3.5 Lateral braces shall be allowed to act as Lateral braces shall be allowed to act aslongitudinal braces if they are within 24 in. (610 mm)longitudinal braces if they are within 24 in. (610 mm)of the centerline of the piping braced longitudinallyof the centerline of the piping braced longitudinallyfor lines that are 2 1/2 in. (76 mm) and greater infor lines that are 2 1/2 in. (76 mm) and greater indiameter.diameter.

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BRACE FASTENER

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9.3.5.39.3.5.3 : Where the spacing of lateral branches is : Where the spacing of lateral branches ispermitted to be up to 50 ft. (7.6 m), the distance betweenpermitted to be up to 50 ft. (7.6 m), the distance betweenthe last brace and the end of the pipe is permitted to bethe last brace and the end of the pipe is permitted to beextended to 25 ft. (1.2 m). extended to 25 ft. (1.2 m). REMOVED BY TIAREMOVED BY TIA

9.3.5.3.7 Lateral sway bracing shall not be required on9.3.5.3.7 Lateral sway bracing shall not be required onpipes individually supported by rods less than 6 in (152pipes individually supported by rods less than 6 in (152mm) long measured between the top of the pipe and themm) long measured between the top of the pipe and thepoint of attachment to the building structure.point of attachment to the building structure.

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9.3.5.3.6: Where flexible couplings are flexible 9.3.5.3.6: Where flexible couplings are flexiblecouplings are installed on mains other than ascouplings are installed on mains other than asrequired in 6-4.2, a lateral brace shall be providedrequired in 6-4.2, a lateral brace shall be providedwithin 24 in. (610 mm) of every other coupling, butwithin 24 in. (610 mm) of every other coupling, butnot more than 40 ft. (12 m) on center.not more than 40 ft. (12 m) on center.

9.3.5.3.8: U-type hooks of the wrap-a-round type or9.3.5.3.8: U-type hooks of the wrap-a-round type orthose U-type hooks arranged to keep the pipe tightthose U-type hooks arranged to keep the pipe tightto the underside of the structural element shall beto the underside of the structural element shall bepermitted to be used to satisfy the requirements forpermitted to be used to satisfy the requirements forlateral sway bracing provided the legs are bent out atlateral sway bracing provided the legs are bent out atleast 30 degrees from the vertical and the maximumleast 30 degrees from the vertical and the maximumlength of each leg and the rod size satisfies thelength of each leg and the rod size satisfies theconditions of Tables 9.3.5.8.9 a,b & c.conditions of Tables 9.3.5.8.9 a,b & c.

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9-3.5.4.1 Longitudinal sway bracing spaced at a9-3.5.4.1 Longitudinal sway bracing spaced at amaximum of 80 ft. (24 m) on center shall be providedmaximum of 80 ft. (24 m) on center shall be providedfor feed and cross mains.for feed and cross mains.

9.3.5.4.2 Longitudinal braces shall be permitted to9.3.5.4.2 Longitudinal braces shall be permitted toserve as lateral braces where they are install withinserve as lateral braces where they are install within24 in. (609 mm) of the piping that is braced laterally.24 in. (609 mm) of the piping that is braced laterally.

9.3.5.4.3 The distance between the last brace and9.3.5.4.3 The distance between the last brace andthe end of the pipe shall not exceed 40 ft. (12.2 m).the end of the pipe shall not exceed 40 ft. (12.2 m).

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9.3.5.5* Risers9.3.5.5* Risers9.3.5.5.1 Tops of risers shall be secured against drifting in9.3.5.5.1 Tops of risers shall be secured against drifting inany direction, utilizing a four-way sway brace.any direction, utilizing a four-way sway brace.

9.3.5.5.2 Distance between four-way braces for risers shall9.3.5.5.2 Distance between four-way braces for risers shallnot exceed 25ft.not exceed 25ft.

9.3.5.5.3 Four-way bracing shall not be required where9.3.5.5.3 Four-way bracing shall not be required whererisers penetrate intermediate floors in multistory buildingsrisers penetrate intermediate floors in multistory buildingswhere the clearance does not exceed the limits of 9.3.4.where the clearance does not exceed the limits of 9.3.4.

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9.3.5.6* Horizontal Force Factors9.3.5.6* Horizontal Force Factors9.3.5.6.1 Unless the requirements of 9.3.5.6.2 are9.3.5.6.1 Unless the requirements of 9.3.5.6.2 aremet, the horizontal loads for braces shall bemet, the horizontal loads for braces shall bedetermined by analysis based on a horizontal forcedetermined by analysis based on a horizontal forceof Fp = 0.5 Wp, where Fp is the horizontal forceof Fp = 0.5 Wp, where Fp is the horizontal forcefactor and Wp is 1.15 times the weight of the water-factor and Wp is 1.15 times the weight of the water-filled piping.filled piping.

9.2.5.6.2 Where the use of horizontal force factors9.2.5.6.2 Where the use of horizontal force factorsother than the horizontal force factor required byother than the horizontal force factor required by9.3.5.6.1 is required or permitted by the authority9.3.5.6.1 is required or permitted by the authorityhaving jurisdiction, they shall take precedence.having jurisdiction, they shall take precedence.

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9.3.5.7 Where the horizontal force factors used9.3.5.7 Where the horizontal force factors usedexceed 0.5 Wp and the brace angle is less than 45exceed 0.5 Wp and the brace angle is less than 45degrees from vertical or where the horizontal forcedegrees from vertical or where the horizontal forcefactor exceeds 1.0 Wp and the brace angle is lessfactor exceeds 1.0 Wp and the brace angle is lessthan 60 degrees from vertical, the braces shall bethan 60 degrees from vertical, the braces shall bearranged to resist the net vertical reaction producedarranged to resist the net vertical reaction producedby the horizontal load.by the horizontal load.

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Seismic Design for Sprinkler SystemsSeismic Design for Sprinkler Systems9.3.5.8* Sway bracing shall be tight. For individual9.3.5.8* Sway bracing shall be tight. For individualbraces, the slenderness ratio (l/r) shall not exceedbraces, the slenderness ratio (l/r) shall not exceed300 where l is the length of the brace and r is the300 where l is the length of the brace and r is theleast radius of gyration. Where threaded pipe isleast radius of gyration. Where threaded pipe isused as part of a sway brace assembly, it shall notused as part of a sway brace assembly, it shall notbe less than Schedule 30. All parts and fittings of abe less than Schedule 30. All parts and fittings of abrace shall lie in a straight line to avoid eccentricbrace shall lie in a straight line to avoid eccentricloading on fittings and fasteners. For longitudinalloading on fittings and fasteners. For longitudinalbraces only, the brace shall be permitted to bebraces only, the brace shall be permitted to beconnected to a tab welded to the pipe inconnected to a tab welded to the pipe inconformance with 3-6.2. For individual braces, theconformance with 3-6.2. For individual braces, theslenderness ratio, l/r, shall not exceed 300 where l isslenderness ratio, l/r, shall not exceed 300 where l isthe length of the brace and r is the least radius ofthe length of the brace and r is the least radius ofgyration. For tension-only braces, two tension-onlygyration. For tension-only braces, two tension-onlybrace components opposing each other must bebrace components opposing each other must beinstalled at each lateral or longitudinal brace location.installed at each lateral or longitudinal brace location.(Cont.)(Cont.)

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For all braces, whether or not listed , the maximumFor all braces, whether or not listed , the maximumallowable horizontal load shall be based on theallowable horizontal load shall be based on theweakest component of the brace with safety factors.weakest component of the brace with safety factors.The loads determined in 9.3.5.6 shall not exceed theThe loads determined in 9.3.5.6 shall not exceed thelesser of the maximum allowable loads provided inlesser of the maximum allowable loads provided inTable 9.3.5.8 or the manufacturerTable 9.3.5.8 or the manufacturer’’s certifieds certifiedmaximum allowable horizontal loads for 30 to 44maximum allowable horizontal loads for 30 to 44degree, 45 to 59 degree, 60 to 89 degree, and 90degree, 45 to 59 degree, 60 to 89 degree, and 90degree brace angles These certified allowabledegree brace angles These certified allowablehorizontal loads must include a minimum safetyhorizontal loads must include a minimum safetyfactor of 1.5 against the ultimate break strength offactor of 1.5 against the ultimate break strength ofthe brace components and then be further reducedthe brace components and then be further reducedaccording to the brace angles.according to the brace angles.


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9.3.5.8.11 Other pipe schedules and materials not9.3.5.8.11 Other pipe schedules and materials notspecifically included in Table 6-4.5.8 shall bespecifically included in Table 6-4.5.8 shall bepermitted to be used if certified by a registeredpermitted to be used if certified by a registeredprofessional engineer to support the loadsprofessional engineer to support the loadsdetermined in accordance with the above criteria.determined in accordance with the above criteria.Calculations shall be submitted where required byCalculations shall be submitted where required bythe authority having jurisdiction.the authority having jurisdiction.

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9.3.5.9* Fasteners9.3.5.9* Fasteners

For individual fasteners, the loads determined in 6-For individual fasteners, the loads determined in 6-4.5.6 shall not exceed the allowable loads provided4.5.6 shall not exceed the allowable loads providedin Figure 6-4.5.9. The type of fastener used toin Figure 6-4.5.9. The type of fastener used tosecure the bracing assembly to the structure shall besecure the bracing assembly to the structure shall belimited to those shown in Figure 6-4.5.9. Forlimited to those shown in Figure 6-4.5.9. Forconnections to wood, through bolts with washers onconnections to wood, through bolts with washers oneach end shall be used. Holes for through boltseach end shall be used. Holes for through boltsshall be 1/16 in. (1.6 mm) greater than the diametershall be 1/16 in. (1.6 mm) greater than the diameterof the bolt.of the bolt.


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9.3.5.9.4 Where it is not practical to install through9.3.5.9.4 Where it is not practical to install throughbolts due to the thickness of the member orbolts due to the thickness of the member orinaccessibility, lag screws shall be permitted. Holesinaccessibility, lag screws shall be permitted. Holesshall be pre-drilled 1/8 in. (3.2 mm) smaller than theshall be pre-drilled 1/8 in. (3.2 mm) smaller than themaximum root diameter of the lag screw.maximum root diameter of the lag screw.

9.3.5.9.6 Other fastening methods are acceptable9.3.5.9.6 Other fastening methods are acceptablefor use if certified by a registered professionalfor use if certified by a registered professionalengineer to support the loads determined inengineer to support the loads determined inaccordance with the criteria in 6-4.5.9. Calculationsaccordance with the criteria in 6-4.5.9. Calculationsshall be permitted where required by the authorityshall be permitted where required by the authorityhaving jurisdiction.having jurisdiction.

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9.3.5.10 Assemblies9.3.5.10 Assemblies

9.3.5.10.1 Sway bracing assemblies shall be listed9.3.5.10.1 Sway bracing assemblies shall be listedfor a maximum load rating, unless the requirementsfor a maximum load rating, unless the requirementsof 9.3.5.10.2 are metof 9.3.5.10.2 are met

9.3.5.10.2 Where sway bracing utilizing pipe, angles,9.3.5.10.2 Where sway bracing utilizing pipe, angles,flats, or rods as shown in Table 6-4.5.8 is used, theflats, or rods as shown in Table 6-4.5.8 is used, thecomponents do not require listing. Bracing fittingscomponents do not require listing. Bracing fittingsand connections used with those specific materialsand connections used with those specific materialsshall be listed.shall be listed.

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Restraint Restraint –– 9.3.6 9.3.6

9.3.6.1 Restraint is considered a lesser degree of resisting9.3.6.1 Restraint is considered a lesser degree of resistingloads than bracing and shall be provided by use of one ofloads than bracing and shall be provided by use of one ofthe following:the following:

11 A listed sway brace assembly.A listed sway brace assembly.22 A wrap-a-round U-hook satisfying the requirements of 6-A wrap-a-round U-hook satisfying the requirements of 6-

4.5.3, Exception Number 3.4.5.3, Exception Number 3.33 No.12, 440 lb (200 kg) wire installed at least 45 degreesNo.12, 440 lb (200 kg) wire installed at least 45 degrees

from the vertical plane and anchored on both sides of thefrom the vertical plane and anchored on both sides of thepipe.pipe.

44 Other approved means.Other approved means.


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Seismic Design for Sprinkler SystemsSeismic Design for Sprinkler SystemsWire used for restraint shall be located within 2 ft (60Wire used for restraint shall be located within 2 ft (60mm) of a hanger. The hanger closest to a wiremm) of a hanger. The hanger closest to a wirerestraint shall be of a type that resists upwardrestraint shall be of a type that resists upwardmovement of a branch line.movement of a branch line.

9.3.6.2 The end sprinkler on a line shall be9.3.6.2 The end sprinkler on a line shall berestrained against excessive vertical and lateralrestrained against excessive vertical and lateralmovement.movement.

9.3.6.3 Where upward or lateral movement would9.3.6.3 Where upward or lateral movement wouldresult in an impact against the building structure,result in an impact against the building structure,equipment, or finish materials, branch lines shall beequipment, or finish materials, branch lines shall berestrained at intervals not exceeding 30 ft (9 m).restrained at intervals not exceeding 30 ft (9 m).

9.3.6.5* Sprig ups 4 ft (1.2 m) or longer shall be9.3.6.5* Sprig ups 4 ft (1.2 m) or longer shall berestrained against lateral movement.restrained against lateral movement.

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9.3.7.1 C-type clamps (including beam and large9.3.7.1 C-type clamps (including beam and largeflange clamps) used to attach hangers to the buildingflange clamps) used to attach hangers to the buildingstructure in areas subject to earthquakes shall bestructure in areas subject to earthquakes shall beequipped with a retaining strap. The retaining strapequipped with a retaining strap. The retaining strapshall be listed for use with a C-type clamp or shall beshall be listed for use with a C-type clamp or shall bea steel strap of not less tan 16 gauge thickness anda steel strap of not less tan 16 gauge thickness andnot less than 1 in (25.4 mm) wide for pipe diametersnot less than 1 in (25.4 mm) wide for pipe diameters8 in (203 mm) or less and 14 gauge thickness and8 in (203 mm) or less and 14 gauge thickness andnot less than 1 1/4 in (31.7 mm) wide for pipenot less than 1 1/4 in (31.7 mm) wide for pipediameters greater than 8 in (203 mm). The retainingdiameters greater than 8 in (203 mm). The retainingstrap shall wrap around the beam flange not lessstrap shall wrap around the beam flange not lessthan 1 in (25.4 mm). A lock nut on a C-type clampthan 1 in (25.4 mm). A lock nut on a C-type clampshall not be used as a method of restraint. A lip on ashall not be used as a method of restraint. A lip on a““CC”” or or ““ZZ”” purlin shall not be used as a method of purlin shall not be used as a method ofrestraint. Where purlins or beams do not provide anrestraint. Where purlins or beams do not provide anadequate lip to be secured by a retaining strap, theadequate lip to be secured by a retaining strap, thestrap shall be through-bolted or secured by a self-strap shall be through-bolted or secured by a self-tapping screw.tapping screw.

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9.3.7.7 C-type clamps (including beam and large9.3.7.7 C-type clamps (including beam and large flange clamps), with or without retaining straps, shall flange clamps), with or without retaining straps, shall not be used to attach braces to the building. not be used to attach braces to the building.

9.3.7.8 Power-driven fasteners shall not be used to9.3.7.8 Power-driven fasteners shall not be used toattach braces to the building structure, unless they areattach braces to the building structure, unless they arespecifically listed for service in resisting lateral loads inspecifically listed for service in resisting lateral loads inareas subject to earthquakes.areas subject to earthquakes.

9.3.7.9: In areas where the horizontal force factor9.3.7.9: In areas where the horizontal force factorexceeds 0.50 Wp, Powder-driven fasteners shall beexceeds 0.50 Wp, Powder-driven fasteners shall bepermitted to attach hangers to the building structurepermitted to attach hangers to the building structurewhere they are specifically listed for use in areaswhere they are specifically listed for use in areassubject to earthquakes.subject to earthquakes.

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νν Seismic Design & LayoutSeismic Design & Layoutνν Steps to layout and sizingSteps to layout and sizing

1. Determine the distance of the piping from the1. Determine the distance of the piping from thestructure.structure.2. Choose a brace type/shape from Table 9-3.5.8.92. Choose a brace type/shape from Table 9-3.5.8.9that the maximum l/r ratio does not exceed 300.that the maximum l/r ratio does not exceed 300.Remember, the angle of your braces should be atRemember, the angle of your braces should be atleast 30least 30°°. Try to make it 45 or more.. Try to make it 45 or more.3. Determine the total load applied to each brace in3. Determine the total load applied to each brace inaccordance with the examples shown in Figure A-9-accordance with the examples shown in Figure A-9-3.5.6(e).3.5.6(e).

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a. The loads on lateral braces on cross mains, adda. The loads on lateral braces on cross mains, addone-half (1/2) the weight of the branch to one-halfone-half (1/2) the weight of the branch to one-half(1/2) the weight of the portion of the cross main(1/2) the weight of the portion of the cross mainwithin the zone of influence of the brace. (1,3,6,7)within the zone of influence of the brace. (1,3,6,7)b. For the loads on longitudinal braces on crossb. For the loads on longitudinal braces on crossmains, consider only one-half (1/2) the weight of themains, consider only one-half (1/2) the weight of thecross mains and feed mains within the zone ofcross mains and feed mains within the zone ofinfluence. Branchlines do not need to be included.influence. Branchlines do not need to be included.(2,4,5,7,8)(2,4,5,7,8)

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c. For the four-way brace at the riser, add thec. For the four-way brace at the riser, add thelongitudinal and lateral loads within the ZOI of thelongitudinal and lateral loads within the ZOI of thebrace (2,3,5). For the four-way at the top of thebrace (2,3,5). For the four-way at the top of theriser, half the weight of the riser should be assignedriser, half the weight of the riser should be assignedto both the lateral and longitudinal loads as they areto both the lateral and longitudinal loads as they areseparately considered.separately considered.4. If the total expected loads are less than the4. If the total expected loads are less than themaximums permitted in Table 6-4.5.8 for themaximums permitted in Table 6-4.5.8 for theparticular brace and orientation, go on to step 5. Ifparticular brace and orientation, go on to step 5. Ifnot, add additional braces to reduce the ZOI.not, add additional braces to reduce the ZOI.

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5. Check that fasteners connecting the braces to5. Check that fasteners connecting the braces tostructural supporting members are adequate tostructural supporting members are adequate tosupport the expected loads on the braces insupport the expected loads on the braces inaccordance with Table 6-4.5.8. If not, again addaccordance with Table 6-4.5.8. If not, again addadditional braces or additional means of support.additional braces or additional means of support.

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A A Exercise #1 Exercise #1 –– Bracing Layout Bracing Layout

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