Essentials

							Essentials of Fire Fighting,
         5th Edition

 Chapter 16 — Fire Detection,
Alarm, and Suppression Systems
        Firefighter II
Chapter 16 Lesson Goal

• After completing this lesson, the
 student shall be able to operate
 different types of fire detection, alarm,
 and suppression systems and identify
 the different types of alarm and
 auxiliary systems following the policies
 and procedures set forth by the
 authority having jurisdiction (AHJ).
                 Firefighter II
                     16–1
Specific Objectives

 1. Describe types of heat detectors.
 2. Describe types of smoke
    detectors/alarms.
 3. Explain how flame detectors and fire-
    gas detectors operate.


                                      (Continued)


                 Firefighter II
                     16–2
Specific Objectives

 4. Discuss combination detectors and
    indicating devices.
 5. Describe types of automatic alarm
    systems.
 6. Discuss supervising fire alarm systems
    and auxiliary services.

                                      (Continued)


                 Firefighter II
                     16–3
Specific Objectives

 7. Describe the operation of an
    automatic fire sprinkler system.
 8. Discuss water supply for sprinkler
    systems.
 9. Describe major applications of
    sprinkler systems.


                 Firefighter II
                     16–4
Fixed-Temperature Heat
Detectors

• Relatively inexpensive compared to
  other types of systems
• Can be slowest to activate
• Activate when heated to temperature
  for which rated


                                   (Continued)


                Firefighter II
                    16–5
Fixed-Temperature Heat
Detectors

• Installed in highest portions of room
• Should have activation temperature
 rating slightly above highest ceiling
 temperatures normally inspected in
 space


                                         (Continued)


                 Firefighter II
                     16–6
Fixed-Temperature Heat
Detectors

• Activate by one or
  more of three
  mechanisms
• Fusible device
• Frangible bulb
• Continuous line
  detector

                    Firefighter II
                        16–7
Rate-of-Rise Heat Detectors

• Operate on assumption that
  temperature in room will increase
  faster from fire than from normal
  atmospheric heating
• Designed to initiate signal when rise in
  temperature exceeds 12° to 15°F
  (-11°C to -9°C) in one minute
                                      (Continued)


                 Firefighter II
                     16–8
Rate-of-Rise Heat Detectors

• Can be initiated at room temperature
  far below that required for initiating
  fixed-temperature device
• Reliable, not subject to false activations
• Pneumatic rate-of-rise spot detector


                                        (Continued)


                  Firefighter II
                      16–9
Rate-of-Rise Heat Detectors

• Pneumatic rate-of-rise line detector
• Rate-compensated detector
• Thermoelectric detector




                 Firefighter II
                    16–10
Smoke Detectors




• Detect presence of smoke; must
  transmit signal to another device that
  sounds alarm
• Respond to smoke or other products of
  combustion
• Preferred over heat detectors
                Firefighter II
                   16–11
Smoke Alarms




• Capable of
  – Detecting presence of smoke
  – Sounding an alarm


                 Firefighter II
                    16–12
Photoelectric Smoke Detectors




• Use photoelectric cell coupled with
  tiny light source
• Function in two ways to detect smoke
                Firefighter II
                   16–13
Ionization Smoke Detectors

• Detect minute particles, aerosols
  produced during combustion
• Use a tiny amount of radioactive
  material to ionize air molecules as
  they enter chamber within detector


                                      (Continued)


                Firefighter II
                   16–14
Ionization Smoke Detectors

• Respond
  satisfactorily to
  most fires
• Respond faster to
  flaming fires than
  smoldering ones


                 Firefighter II
                    16–15
Power Sources of Smoke Alarms

• Battery-operated
• Household current




                Firefighter II
                   16–16
Flame Detectors

• Types
• Among most sensitive detectors used to
  detect fires
• Prone to being activated by nonfire
  conditions


                                        (Continued)


                 Firefighter II
                    16–17
Flame Detectors

• Usually positioned in areas
  where other light sources
  unlikely
• Positioned to have
  unobstructed view of
  protected area

                                  (Continued)


                 Firefighter II
                    16–18
Flame Detectors

• Some single-band IR detectors sensitive
  to sunlight, should be installed in fully
  enclosed areas
• UV detectors virtually insensitive to
  sunlight, can be used in areas not
  suitable for IR detectors



                  Firefighter II
                     16–19
Fire-Gas Detectors

• Monitor levels of carbon dioxide, carbon
  monoxide because these are only
  chemicals released from all fires
• Initiate alarm signal faster than heat
  detector but not as quickly as smoke
  detector

                                       (Continued)


                  Firefighter II
                     16–20
Fire-Gas Detectors

• Can be more discriminating than other
  types
• Can be designed to be sensitive only
  to specific gases



                                    (Continued)


                Firefighter II
                   16–21
Fire-Gas Detectors




• Use semiconductors/catalytic elements
  to sense gas, transmit signal to initiate
  alarm
• Not used as frequently as other types
                  Firefighter II
                     16–22
Combination Detectors




Various combinations of previously
described means of detection may be
used in single device
                Firefighter II
                   16–23
Indicating Devices

• Some produce loud signal
  to attract attention in
  high-noise areas
• Some generate electronic
  tone audible in almost any type of
  environment
• Some employ bells, horns, chimes
                                       (Continued)


                Firefighter II
                   16–24
Indicating Devices

• Others use speakers that
  broadcast prerecorded
  evacuation instructions
• May include visual
  alarm indicators to
  accommodate special
  circumstances/populations
                                (Continued)


               Firefighter II
                  16–25
Indicating Devices

         • May include strobe
           indicators — Must meet
           requirements of Americans
           with Disabilities Act in
           areas where there may be
           people with hearing
           impairments


             Firefighter II
                16–26
Automatic Alarm Systems

• Transmit signal to off-site location to
  summon organized assistance
• Produce automatic response upon
  activation of local alarm
• May be installed to complement wet-
  pipe or dry-pipe sprinkler systems


                  Firefighter II
                     16–27
Auxiliary Systems

• Local energy systems
• Shunt systems
• Parallel telephone
 systems




                Firefighter II
                   16–28
Remote Station Systems

• Similar to auxiliary systems but
   connected to fire department
   telecommunication center
   directly/through answering service by
   some means other than municipal fire
   alarm box system

                                     (Continued)


                 Firefighter II
                    16–29
Remote Station Systems

• Can be connected by leased telephone
  line or radio signal on dedicated
  frequency
• Common in localities not served by
  central station systems


                                       (Continued)


                 Firefighter II
                    16–30
Remote Station Systems

• May transmit coded or noncoded
  signal
• Must have ability to transmit trouble
  signal to fire alarm center when
  system impaired


                                     (Continued)


                 Firefighter II
                    16–31
Remote Station Systems




• May not have local alarm capabilities if
  evacuation is not desired action in fire
• May be monitored by entity besides fire
  department
                  Firefighter II
                     16–32
Proprietary Systems

• Used to protect
   large commercial,
   industrial buildings,
   high-rise buildings,
   groups of
   commonly owned
   buildings in single
   location                        (Continued)


                  Firefighter II
                     16–33
Proprietary Systems

• Each building/area has own system
  wired into a common receiving point
  somewhere on facility
• The receiving station
• Capabilities



                Firefighter II
                   16–34
Central Station Systems

• Very similar to proprietary systems;
   instead of having alarm-receiving
   point monitored by occupant’s
   representative on protected premises,
   receiving point is at off-site,
   contracted service point called a
   central station
                                     (Continued)


                Firefighter II
                   16–35
Central Station Systems

                      • Central station is
                          alarm company
                          that contracts
                          with individual
                          customers



                                       (Continued)


             Firefighter II
                16–36
Central Station Systems

• When alarm initiated at contracting
  occupancy, central station employees
  take information, initiate appropriate
  emergency response
• Response usually includes calling fire
  department, representatives of
  protected occupancy
                                     (Continued)


                 Firefighter II
                    16–37
Central Station Systems

• Alarm systems at protected property
 and central station most commonly
 connected by supervised telephone
 lines




                Firefighter II
                   16–38
Supervising Fire Alarm Systems

• Designed to be self-supervising
• Older systems
• Newer systems




                                    (Continued)


                Firefighter II
                   16–39
Supervising Fire Alarm Systems

• Sounds of alarm, trouble signals may
  differ with each brand
• Many fixed fire suppression systems
  depend on signal from manual pull
  station/from automatic fire detection
  device to trigger suppression system



                 Firefighter II
                    16–40
Auxiliary Services Available on
Newer Systems

• Shutting down, altering airflow in
  heating, ventilating, and air-
  conditioning (HVAC) systems for
  smoke control
• Closing smoke/fire-rated doors,
  dampers

                                       (Continued)


                 Firefighter II
                    16–41
Auxiliary Services Available on
Newer Systems

• Facilitating evacuation by increasing air
  pressure in stairwells to exclude smoke
• Overriding elevator controls
• Monitoring operation of commercial
  incinerator management systems


                                       (Continued)


                  Firefighter II
                     16–42
Auxiliary Services Available on
Newer Systems

• Monitoring refrigeration systems, cold-
  storage areas
• Controlling personnel access to
  hazardous process/storage areas
• Detecting combustible/toxic gases



                 Firefighter II
                    16–43
Principle Parts of Automatic
Sprinkler System

•   Water supply
•   Sprinkler valve
•   Alarm
•   Manual valve
•   System drain

                                       (Continued)


                      Firefighter II
                         16–44
Principle Parts of Automatic
Sprinkler System

•   Test connection
•   Sprinkler head
•   Riser
•   Feed main
•   Cross mains



                  Firefighter II
                     16–45
Sprinklers

• Discharge water after release of cap
   or plug activated by some heat-
   responsive element such as fusible
   link



                                        (Continued)


                Firefighter II
                   16–46
Sprinklers

• Identified by temperature at which
 designed to operate, either by color-
 coding, using different colored liquid,
 stamping temperature on sprinkler



                                       (Continued)


                 Firefighter II
                    16–47
Sprinklers

• Fusible link


• Frangible bulb


                                    (Continued)


                   Firefighter II
                      16–48
Sprinklers

• Chemical pellet




                    Firefighter II
                       16–49
Sprinkler Position

• Pendant


• Upright


                              (Continued)


             Firefighter II
                16–50
Sprinkler Position

• Sidewall
• Special-purpose




                Firefighter II
                   16–51
Sprinkler Storage

• Storage cabinet to house spare
  sprinklers, a sprinkler wrench usually
  installed near sprinkler rise, main
  shut-off valve
• Cabinets hold a minimum of six
  sprinklers and sprinkler wrench in
  accordance with NFPA® 13 and 13D
                                     (Continued)


                 Firefighter II
                    16–52
Sprinkler Storage

• In many jurisdictions, job of changing
 sprinklers must be performed by
 representatives of building’s occupants
 qualified to perform work on sprinkler
 systems


                                      (Continued)


                 Firefighter II
                    16–53
Sprinkler Storage

• In other jurisdictions, firefighters
  allowed to replace fused/damaged
  sprinklers to restore system to service
  sooner




                   Firefighter II
                      16–54
Water Supply

• Minimum water supply has to deliver
  required volume of water to highest
  sprinkler in building at residual
  pressure of 15 psi (105 kPa)
• Minimum flow depends on hazard to
  be protected, occupancy, building
  contents
                                   (Continued)


                Firefighter II
                   16–55
Water Supply

• In most cases, water supply for
  sprinkler systems designed to supply
  only fraction of sprinklers actually
  installed on system
• If large fire occurs/pipe breaks,
  sprinkler system will need outside
  source of water and pressure
                                     (Continued)


                 Firefighter II
                    16–56
Water Supply

• Sprinkler FDCs should be supplied with
 water from pumpers that have capacity
 of at least 1,000 gpm (4 000 L/min) or
 greater; minimum of two 2½-inch (65
 mm) or larger hoses should be attached
 to the FDC

                                     (Continued)


                 Firefighter II
                    16–57
Water Supply

• After water flows through FDC into
  system, passes through check valve
• Proper direction of water flow through
  check valve usually indicated by arrow
  on valve or appearance of valve casing




                 Firefighter II
                    16–58
Water Supply

• Departmental preincident plans may
 identify the pressure at which a
 sprinkler system should be supported




                Firefighter II
                   16–59
Wet-Pipe Systems

• Used in locations where
  temperatures below 40°F
  (4°C) not expected
• Simplest type of
  automatic fire sprinkler
  system

                                 (Continued)


                Firefighter II
                   16–60
Wet-Pipe Systems

• Generally require little maintenance
• Contain water under pressure at all
  times
• Connected to public/private water
  supply so fused sprinkler immediately
  discharges water spray, actuates alarm

                                         (Continued)


                 Firefighter II
                    16–61
Wet-Pipe Systems

• Usually equipped with alarm check
  valve installed in main riser adjacent to
  where feed main enters building
• Newer versions may have a backflow
  prevention check valve and electronic
  flow alarm.

                                       (Continued)


                  Firefighter II
                     16–62
Wet-Pipe Systems

• May be equipped with retarding device
 as part of alarm check valve




                Firefighter II
                   16–63
Dry-Pipe Systems

• Used in locations
   where piping may
   be subjected to
   temperatures below
   40°F (4°C)


                                 (Continued)


                Firefighter II
                   16–64
Dry-Pipe Systems

• Have pitched (sloped) pipes to help
  drain water in system back toward main
  drain
• Replace water in sprinkler piping with
  air under pressure


                                        (Continued)


                 Firefighter II
                    16–65
Dry-Pipe Systems

• Designed so small amount of air
  pressure above dry-pipe valve will hold
  back much greater water pressure on
  water supply side of dry-pipe valve
• Equipped with electric or hydraulic
  alarm-signaling equipment

                                      (Continued)


                 Firefighter II
                    16–66
Dry-Pipe Systems

• Larger systems may have several-
 minute delay while air expelled from
 system




                Firefighter II
                   16–67
Preaction Systems

• Dry systems that employ deluge-type
  valve, fire detection device, closed
  sprinklers
• Used when especially important to
  prevent water damage, even if pipes
  broken

                                    (Continued)


                Firefighter II
                   16–68
Preaction Systems

• Will not discharge water into sprinkler
  piping except in response to smoke- or
  heat-detection system actuation
• Sound alarm to give warning before
  opening of sprinklers




                 Firefighter II
                    16–69
Deluge Systems

• Similar to dry-pipe system in no water
  in distribution piping before system
  activation
• Differ from dry-pipe systems in
  sprinklers have no fusible links, do not
  function as fire detection devices

                                      (Continued)


                 Firefighter II
                    16–70
Deluge Systems

• Designed to quickly supply large volume
  of water to protected area
• Sometimes used to discharge
  foam/other extinguishing agents in
  occupancies containing flammable
  liquids, other volatile fuels



                 Firefighter II
                    16–71
Residential Systems

• Installed in one- and two-family
  dwellings
• Designed to give occupants of
  dwelling chance to escape, prevent
  total involvement in room of origin
• Employ quick-response sprinklers
                                     (Continued)


                Firefighter II
                   16–72
Residential Systems

• Use several types of piping systems
• Must have pressure gauge, flow
  detector, means for draining and testing
  system
• Can be either connected directly to
  public water supply or to dwelling’s
  domestic water system
                                        (Continued)


                 Firefighter II
                    16–73
Residential Systems

• Require control valve to turn off water
 to sprinkler system and to domestic
 water system if connected; if sprinkler
 system supplied separately from
 domestic water system, sprinkler
 control valve must be supervised in
 open position
                                      (Continued)


                 Firefighter II
                    16–74
Residential Systems

• Operate in same manner as other wet-
  pipe/dry-pipe systems
• May be equipped with fire department
  connection (FDC); FDC may be 1½-inch
  (38 mm) connection




                Firefighter II
                   16–75
Summary

• Many of the buildings to which
   firefighters are called for emergency
   operations are protected partially or
   fully by automatic fire detection
   and/or suppression systems.


                                      (Continued)


                 Firefighter II
                    16–76
Summary

• Firefighters need to familiarize
  themselves with the types of systems
  installed in their area of responsibility.
  They should also learn the locations of
  these systems as well as the capabilities
  and limitations of each type of system.



                  Firefighter II
                     16–77
Review Questions

1. How does a photoelectric smoke
   detector work?
2. How do flame detectors work?
3. Describe the three basic types of
   auxiliary automatic alarm systems.


                                    (Continued)


                Firefighter II
                   16–78
Review Questions

4. What is a proprietary automatic alarm
   system?
5. Describe commonly used release
   mechanisms to activate sprinklers.




               Firefighter II
                  16–79