Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

2.5 suppression.sprinklers.wk12a


Published on

2.5 suppression.sprinklers.wk12a

  1. 1. Fire Detection and Suppression Chapter 6 Automatic Sprinkler Systems
  2. 2. Sprinkler Systems <ul><li>Purpose : Discharge an extinguishing agent onto a fire while the fire is in the incipient stage </li></ul>* Should be simple , reliable , automatic , & use a readily available and inexpensive extinguishing agent Understanding sprinkler system operation is important so that firefighting operations in sprinklered buildings can be carried out in the most efficient manner.
  3. 3. Sprinkler System Effectiveness <ul><li>Reliability factor of 96% when sprinkler system is installed & maintained properly. </li></ul><ul><li>In 75% of the reported fires in sprinklered buildings, the fire was controlled by 10 or fewer sprinkler heads. </li></ul><ul><li>There has never been a multiple loss of life (3 or more deaths) due to fire and smoke in a building protected by a sprinkler system except in the case of intimate contact with the fire or an explosion. </li></ul>
  4. 4. Reasons that sprinkler systems fail to protect: <ul><ul><li>improper maintenance </li></ul></ul><ul><ul><li>inadequate or inoperative water supply </li></ul></ul><ul><ul><li>incorrect system design </li></ul></ul><ul><ul><li>obstructions in system </li></ul></ul><ul><ul><li>partial protection </li></ul></ul>
  5. 5. Reasons for Installation 1. Code requirements 2. Insurance incentives 3. Fire protection of life & property 4. Flexibility in building design
  6. 6. Standard <ul><ul><li>NFPA 13 - Standard for the Installation of Sprinkler Systems </li></ul></ul>
  7. 7. Sprinkler System Components 1. Water Supply 2. Distribution piping 3. Nozzles a.k.a. Sprinkler Heads 4. Valves 3. Nozzles a.k.a. Sprinkler Heads
  8. 8. Sprinkler : portion of the system that senses the fire, reacts, and then delivers water to the fire area <ul><li>Heat-sensitive device </li></ul><ul><li>Deflector </li></ul><ul><li>Discharge orifice </li></ul>
  9. 9. <ul><li>Fusible link - eutectic metal with a precisely established melting point is connected to a cap; when cap melts, restraining arms fall away and water flows through opening </li></ul>Heat-sensitive device: <ul><li>Frangible Bulb - glass bulb contains liquid that expands when heated to a precise temperature; when liquid expands, the bulb breaks and water can flow </li></ul>
  10. 10. Heat-sensitive device
  11. 11. Heat-sensitive device
  12. 12. Operating Temperatures 135°F 155°F 175°F 200°F 285°F Heat-sensitive device most common
  13. 13. Fusible Link Heat-sensitive device
  14. 14. Response Time Index (RTI) : speed of operation of a sprinkler head; smaller # means faster response <ul><li>There will be a delay between the time when the air reaches a certain temperature and when the sprinkler head operates </li></ul><ul><li>Same as “thermal lag” in heat detectors </li></ul><ul><li>The surface area, mass, and thermal properties of the heat sensing device determine how quickly it will operate </li></ul>ESFR (Early Suppression Fast Response) Sprinkler Heads : Superior design with a very low RTI resulting in 5-10x faster response than standard sprinkler heads Heat-sensitive device
  15. 15. <ul><li>Surface that water hits as it flows </li></ul><ul><li>Determines the discharge pattern </li></ul>Deflector : <ul><li>Old style sprinkler heads deflected some water toward the ceiling to protect structural elements … these are not effective in controlling or extinguishing fires </li></ul>
  16. 16. <ul><li>Upright </li></ul>Sprinkler Head Designs: <ul><li>Pendent </li></ul><ul><li>Sidewall </li></ul><ul><li>*Water spray - specific pattern (conical) to protect a 3D hazard </li></ul>
  17. 17. <ul><li>Standard size is 1 / 2 ” opening </li></ul><ul><li>Flow 15-50 gpm </li></ul><ul><li>Large- and Small-Orifice sprinklers do exist </li></ul>Discharge Orifice :
  18. 18. Sprinkler System Components 1. Water Supply 2. Distribution piping 3. Nozzles a.k.a. Sprinkler Heads 4. Valves 2. Distribution Piping
  19. 19. Sprinkler System Piping Material: <ul><li>Ferrous metal (a.k.a. Steel, Black Steel) - most common, heavy, corrodes </li></ul><ul><li>Copper Tubing - lighter, resists corrosion, less FL, expensive </li></ul><ul><li>Galvanized - steel or iron coated with zinc to protect against corrosion </li></ul><ul><li>Plastic (PVC) - lightest, least expensive, cannot within high ambient temps, needs fire resistant covering </li></ul>
  20. 20. Sprinkler System Piping Size: <ul><li>Hydraulically calculated - mathematical formulas used to calculate flow volume and pressure determine pipe size; requires initial $$$ for engineer but saves money in long run </li></ul><ul><li>Pipe Schedule Method - pipe size (diameter & thickness of pipe wall) determined by # of sprinkler heads to be supplied, excellent performance, may be more $$$ </li></ul>
  21. 21. Sprinkler System Piping Terminology: <ul><li>Water supply main </li></ul><ul><li>System riser </li></ul><ul><li>Spring-up </li></ul><ul><li>Riser </li></ul><ul><li>Feed main </li></ul><ul><li>Cross main </li></ul><ul><li>Branch line </li></ul>
  22. 22. Sprinkler System Components 1. Water Supply 2. Distribution piping 3. Nozzles a.k.a. Sprinkler Heads 4. Valves 4. Valves
  23. 23. Sprinkler System Valves <ul><li>Control valve - shuts off main water supply; normally kept in OPEN position </li></ul><ul><li>Check valves - ensures water flows in only ONE direction </li></ul><ul><li>Automatic Drain valves - allow water to automatically flow out of the piping; used to drain FDCs </li></ul>Operating valves: <ul><li>Alarm check valves - opens when water begins to flow out of a sprinkler head & allows water to flow into small pipe which activates an alarm; needs a retard chamber to prevent accidental alarms </li></ul>
  24. 24. Sprinkler System Valves Operating valves: <ul><li>Globe valves - small handwheel-controlled valves used to open & close small portions of the system (for testing or draining) </li></ul><ul><li>Ball-Drip valves - small quarter-turn valves also used to open & close small portions of the system </li></ul><ul><li>Test valves - controls flow of water to certain areas & allows personnel to verify proper system operation </li></ul>
  25. 26. <ul><li>Gate, indicating </li></ul><ul><li>Gate, non-indicating </li></ul><ul><li>Butterfly, non-indicating </li></ul>a b c
  26. 27. Sprinkler System Components 1. Water Supply 2. Distribution piping 3. Nozzles a.k.a. Sprinkler Heads 4. Valves 1. Water Supply
  27. 28. Sprinkler System Water Supply <ul><li>Public water supply / Fire Pump </li></ul><ul><li>Storage tanks / Fire Pump </li></ul><ul><li>FDC / Engine </li></ul>