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American Fire Sprinkler AssociaEon
DESIGN & LAYOUT OF FIXED SPRAY SYSTEMS E. Parks Moore Be sure to sign name on sign-‐in sheet & submit completed evalua7on to receive credit for this seminar!
GOALS FOR THE SESSION • Review design requirements for various fixed spray systems • Review spacing and locaEons rules • Discuss applicaEons for fixed spray systems
This seminar and its content is not a formal interpreta2on issued pursuant to NFPA regula2ons. Any opinion expressed is the personal opinion of the author and presenter and does not necessarily present the official posi2on of the NFPA and its Technical Commi>ees.
WHAT IS NFPA 15? 1.1 Scope 1.1.1 This standard provides the minimum requirements for the design, installaEon, and system acceptance tesEng of water spray fixed systems for the fire protecEon service…
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HOW IS NFPA 15 APPLIED? 1.3.2 Water spray protecEon is acceptable for the protecEon of hazards involving each of the following groups: 1) Gaseous and liquid flammable materials 2) Electrical hazards such as transformers, oil switches, motors, cable trays, and cable runs 3) Ordinary combusEbles such as paper, wood or texEles 4) Certain hazardous solids such as propellants and pyrotechnics
WATER SPRAY NOZZLES
AutomaEc Spray Nozzle
Open Spray Nozzle
WATER SPRAY NOZZLES
Window Sprinkler Nozzle
Cooling Tower Nozzle
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WATER SPRAY NOZZLES
Spiral Open Spray Nozzle
WATER SPRAY NOZZLES
DEFINITIONS Impingement. The striking of a protected surface by water droplets issuing directly from a water spray nozzle. Net Rate. The total rate of water discharge density, less water wastage due to factors such as wind effects and inaccuracies in nozzle angles of spray.
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DEFINITIONS Rundown. The downward travel of water travel along a surface, caused by the momentum of the water or by gravity. Water Wastage. That discharge from water spray nozzles that does not impinge on the surface being protected.
HOW IS NFPA 15 APPLIED? 4.1 Design ObjecEves. In general, water spray shall be considered effecEve for any one of or a combinaEon of the following objecEves: 1) 2) 3) 4)
ExEnguishing of fire Control of burning Exposure protecEon PrevenEon of fire
SOME PIPING REQUIREMENTS 5.3.6.1 Steel pipe used in manual and open systems shall be galvanized on its internal and external surfaces in accordance with Table 5.3.1. 5.3.6.3 Water-‐filled steel piping shall be permiged to be black. 5.3.6.4 Stainless steel pipe shall not be required to be galvanized.
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SOME FITTING REQUIREMENTS 5.4.3 Galvanized fihngs shall be used where galvanized pipe is used. 5.4.9.1 A one-‐piece reducing fihng shall be used wherever a change is made in the size of the pipe. 5.4.9.1 Hex or face bushings shall be permiged for use in reducing the size of openings of fihngs where standard fihngs of the required size and material are not available from the manufacturer.
WATER SPRAY NOZZLES 6.2.1.1 Open water spray nozzles shall be used. 6.2.1.2 AutomaEc nozzles shall be permiged where posiEoned and located so as to provide saEsfactory performance with respect to acEvaEon Eme and distribuEon.
WATER SPRAY NOZZLES 6.2.1.4 Where acceptable to the AHJ, sprinklers shall be permiged to be used in water spray systems and installed in posiEons other than anEcipated by their lisEng to achieve specific results where special situaEons require.
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WATER SPRAY NOZZLES 6.2.4 The posiEon of water spray nozzles shall include an evaluaEon of all the following factors: 1) The shape and size of the area to be protected 2) The nozzle design and characterisEcs of the water spray pagern to be protected 3) The effect of wind and fire draj on very small drop sizes or on large drop sizes with ligle iniEal velocity 4) The potenEal to miss the target surface and increase water wastage 5) The effects of nozzle orientaEon on coverage characterisEcs 6) The potenEal for mechanical damage
PIPE SUPPORTS 6.3.2.2 Piping shall be supported from steel or concrete structural members or pipe stands. 6.3.2.2.3 Pipe stands shall be constructed of Schedule 40 threaded pipe, malleable iron flange base, and shall have a threaded cap top.
PIPE SUPPORTS
Reprinted with permission from NFPA 15-2007, Standard for Water Spray Fixed Systems for Fire Protection, Copyright © 2007, NFPA, Quincy, MA. This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety.
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PROPOSED CHANGES TO PIPE SUPPORTS
Copyright © 2011. All rights reserved. NFPA and National Fire Protection Association are registered trademarks of the National Fire Protection Association, Quincy, MA.
PIPE SUPPORTS
Reprinted with permission from NFPA 15-2007, Standard for Water Spray Fixed Systems for Fire Protection, Copyright © 2007, NFPA, Quincy, MA. This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety.
PROPOSED CHANGES TO PIPE SUPPORTS
Copyright © 2011. All rights reserved. NFPA and National Fire Protection Association are registered trademarks of the National Fire Protection Association, Quincy, MA.
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WET & DRY PILOT HEADS
DEFINITION – According to NFPA 15, 2007 edi7on a pilot sprinkler is “an automa7c sprinkler or thermosta7c fixed temperature release device used as a detector to pneuma7cally or hydraulically release the system actua7on valve.”
PILOT HEAD LOCATION & SPACING 6.5.2.4.3 Maximum horizontal spacing for indoor locaEons shall not exceed 12 j. 6.5.2.4.5 Pilot sprinklers shall be permiged to be spaced more than 22 in. below a ceiling or deck where the maximum spacing between pilot sprinklers is 10 j or less.
PILOT HEAD LOCATION & SPACING 6.5.2.4.6 Other maximum horizontal spacing differing from those required in 6.5.2.4.2 and 6.5.2.4.3 shall be permiged where installed in accordance with their lisEng. 8.14.7 Pilot sprinklers located outdoors, such as in open process structures, shall be spaced such that the elevaEon of a single level of pilot line detectors and between addiEonal levels of pilot line detectors shall not exceed 17 j. 6.5.2.4.8 The maximum distance between pilot line detectors installed outdoors shall not exceed 8 j.
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PILOT HEAD LOCATION & SPACING 6.5.2.4.9 The horizontal distance between pilot line detectors installed outdoors on a given level shall be permiged to be increased to 10 j when all of the following condiEons are met: (1) The elevaEon of the first level does not exceed 15 j. (2) The distance between addiEonal levels does not exceed 12 j. (3) The pilot sprinklers are staggered verEcally.
PILOT HEAD LOCATION & SPACING A.6.5.2.3 Where detectors are located outdoors or without a ceiling over them to trap the heat, their spacing should be reduced if prompt detecEon is to be achieved. In general, thermal detectors are to be located within the hot air currents created by the fire if they are to operate. A 50 percent reducEon in the spacing between detectors is required in the absence of test data on a parEcular detector and fire size. Some guidance might be available from the manufacturer. The sensiEvity of other detectors (e.g., flammable gas detectors) can also be adversely affected by wind or the lack of walls or ceilings surrounding the hazard.
PILOT HEAD LOCATION & SPACING Heat collectors located above the pilot sprinklers or other thermal detectors for the sole purpose of trapping heat are not recommended. They are considered protected canopies (see 6.5.1.2). They can provide some benefit if they are of sufficient size [18 in. × 18 in., or larger] to trap heat. Smaller collectors can reduce sensiEvity by causing a “dead” air space. However, shields or canopies needed to protect the detector from the weather should not be eliminated because of concerns they might reduce detector sensiEvity. Other types of detectors, such as UV detectors that do not rely on air currents to detect a fire or hazardous condiEon might not require a reduced spacing when they are used outdoors.
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PILOT HEAD LOCATION & SPACING
PILOT HEAD LOCATION & SPACING DRY PILOT HEADS
PILOT HEAD LOCATION & SPACING
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PILOT HEAD LOCATION & SPACING 6.5.2.5.1.1 Detectors located in open-‐sided buildings shall follow the indoor spacing rules. 6.5.2.5.1.2 A line of detectors spaced in accordance with the outdoor pilot line detector spacing rules shall be located along the open sides of open-‐sided buildings. 6.5.2.5.2 Detectors located under open graEngs shall be spaced in accordance with 6.5.2.3 [the outdoor rules].
SPECIALLY LISTED PILOT HEADS • Refer to manufacturer’s lisEng, NFPA 15, and NFPA 72 for spacing and locaEon rules • Up to 40’ x 40’ for indoor installaEon under a smooth flat ceiling ≤ 10’ • The distance from the detector to all points in the area of coverage shall not exceed 70% (0.7S) of the lisEng spacing • For outdoor spacing reduce the listed spacing by at least 50%
PILOT HEAD LIMITATIONS • Wet pilot limited to areas not subject to freezing. • Must be mindful of water column when designing systems u7lizing wet pilot. There are limita7ons on the maximum height of the pilot lines above the deluge valve depending on: – – – –
Available water supply Size of the valve Manufacturer of the valve Refer to valve manufacturer’s recommenda7ons for guidance
• Dry pilot heads need a reliable source of compressed air • Condensa7on in air lines may lead to freeze problems
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PILOT HEAD APPLICATIONS • Industrial (Area protecEon, steel protecEon, vessel protecEon) • Commercial (Coolers, Freezers, Warehouses) • Exposure protecEon
LINEAR HEAT DETECTION
• DEFINITION – A linear heat detector is a temperature sensing wire capable of detec7ng heat anywhere along its length.
LINEAR HEAT DETECTION APPLICATIONS & LIMITATIONS
• Wire is suscepEble to severing • Must be installed in conEnuous runs • Cable trays, freezers, conveyors
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SPOT TYPE HEAT DETECTION
3.3.43.21 Spot-‐Type Detector. A device in which the detecEng element is concentrated at a parEcular locaEon.
HEAT DETECTORS APPLICATIONS & LIMITATIONS • Slower response Eme to fire than flame or smoke detectors (thermal lag). • Detectors need to be located relaEvely close to the heat source. • ApplicaEons – Open air environments too dirty for smoke detectors – Warehouses, ahcs, transformers, exposure protecEon
HEAT DETECTOR APPLICATIONS
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HEAT DETECTOR APPLICATIONS
RATE OF RISE DETECTORS • How does it work? – Most rate of rise detectors are calibrated to actuate when the temperature rises more than 15 degrees F in one minute. • Therefore limited to areas not suscepEble to sudden large fluctuaEons in temperature.
RATE OF RISE DETECTORS • SPACING RULES – Determined by the lisEng of the device • Typically can cover up to 50’ x 50’ • De-‐raEng of spacing for ceiling height applies
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RATE OF RISE DETECTORS
RATE OF RISE DETECTORS
MANUAL RELEASES • 6.4.2.1 At least one manual actuaEon device independent of the manual actuaEon device at the system actuaEon valve shall be installed for all automaEc systems. • 6.4.2.2 Where the manual release at the systems actuaEon valve meets the requirements of 6.4.2.1, a separate remote manual acEvaEon device shall not be required. • 6.4.2.3 Systems that protect normally unoccupied areas shall not require a separate manual acEvaEon means.
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MANUAL RELEASES • 6.4.2.4 Remote manual actuaEon devices shall be located so as to be accessible during an emergency. • 6.4.2.5 Remote manual actuaEon devices shall be idenEfied with a permanently marked weatherproof metal or rigid plasEc sign idenEfying the system(s) controlled.
MANUAL RELEASES
MANUAL RELEASES
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Flame Detectors
Flame Detectors • Ultraviolet Light (UV) Detectors – Can respond to a fire in less than 10 milliseconds – Not good for areas with arc welding
• Infrared Detectors – Can respond to a fire in less than 50 milliseconds – Respond to hydrocarbon fires
Flame Detectors UV/IR Detectors – Require simultaneous detecEon of both UV and IR light spectrums for alarm – More resistant to false alarms
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Flame Detector ApplicaEons • Large open areas unacceptable for heat or smoke detectors • High hazard areas requiring very fast detecEon • Hangars, Tarmacs, Railcar Loading StaEons, Drilling Playorms, LNG & LPG FaciliEes)
Flame Detector ApplicaEons
Design ObjecEves 7.1 System Design 7.1.1 Systems shall be arranged for automaEc operaEon with supplementary manual tripping means provided. 7.1.2 Manual operaEon shall be permiged where automaEc operaEon of the system presents a hazard to personnel. 7.1.3 Manual operaEon of the system shall be permiged where a system is isolated and agended by trained personnel at all Emes.
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Design ObjecEves 7.1.7 The design shall ensure that the nozzle spray pagerns meet or overlap. 7.1.8 Nozzle spacing (verEcally and horizontally) shall not exceed 10 j. 7.1.9 Nozzles shall be permiged to exceed the spacing requirements of 7.1.8 where listed for spacing exceeding 10j.
Design DensiEes Cable Trays (smoldering) 0.15 gpm/j2 Cable Trays (spill fire) 0.30 gpm/j2 Conveyors 0.15 gpm/j2 Pumps & Compressors 0.50 gpm/j2 Flammable Liquid Pool Fires 0.30 gpm/j2 Vessels 0.25 gpm/j2 Horizontal Steel ProtecEon 0.10 gpm/j2 VerEcal Steel ProtecEon 0.25 gpm/j2 Transformers 0.25 gpm/j2 Transformers (non-‐abs. grnd) 0.15 gpm/j2
Belt Conveyors • Direct spray nozzles to exEnguish fires in hydraulic oil, the belt, and contents • Provide interlocks for machinery shutdown • Protect the drive rolls, take-‐up rollers, power and hydraulic units • Spray shall wet top belt, its contents, and the bogom return belt
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Reprinted with permission from NFPA 15-2007, Standard for Water Spray Fixed Systems for Fire Protection, Copyright © 2007, NFPA, Quincy, MA. This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety.
Reprinted with permission from NFPA 15-2007, Standard for Water Spray Fixed Systems for Fire Protection, Copyright © 2007, NFPA, Quincy, MA. This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety.
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Belt Conveyors
Belt Conveyors
Belt Conveyors
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Structural Steel ProtecEon • Protect (primary) structural steel members such as beams or columns. • NFPA 15 defines the weged surface as one side of the web and the inside surface of one side of the flanges. • Nozzles preferred on alternaEng sides.
Structural Steel ProtecEon
Reprinted with permission from NFPA 15-2007, Standard for Water Spray Fixed Systems for Fire Protection, Copyright © 2007, NFPA, Quincy, MA. This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety.
Structural Steel ProtecEon
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Vessels • Where rundown is expected the distance between nozzles verEcally shall not exceed 12 j. • Spray pagerns shall meet or overlap between horizontally spaced nozzles.
Reprinted with permission from NFPA 15-2007, Standard for Water Spray Fixed Systems for Fire Protection, Copyright © 2007, NFPA, Quincy, MA. This reprinted material is not the complete and official position of the NFPA on the referenced subject, which is represented only by the standard in its entirety.
• Rundown shall not be allowed to be considered for spheres or horizontal cylindrical vessels below the equator of the vessel.
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Vessels
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Pumps and Compressors • Protect the shajs, seals and other criEcal parts with direct impingement of water. • Protect areas where spills are likely to occur.
Transformers • Complete water spray impingement over all exposed surfaces. • Protect underneath elevated transformers. • Non-‐absorbing ground surfaces shall be protected.
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Transformers • Any spaces > 12” wide shall be protected. • Avoid spraying energized components • Maintain required clearances from energized parts.
Transformers
Transformers
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Transformers
Strainers • NFPA 15 requires mainline strainers where nozzles with orifice less than 3/8” (approx. K=4.1) are used. • Integral head strainers are required when orifice less than 3/16” are used. • NFPA 13 requires strainers for sprinklers with K-‐factor less than 2.8.
Strainers
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CalculaEons • Min. operaEng pressure for outdoor nozzles shall be 20 psi. • Some AHJs require 30 psi for outdoor locaEons. • Nozzles protecEng interior hazards shall have min. starEng pressures per their lisEngs.
CalculaEons • Velocity pressure shall be used in hydraulic calculaEons. • May ignore velocity pressure where the Pv doesn’t exceed 5% of PT.
Sample Problem D = 10 j. L = 20 j. Ends = Hemispher. Saddles = 10” Tall No Appendages
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THANK YOU Please submit a completed
evaluaEon form before you leave to receive credit for this class.
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