Fire detection, alarm, and suppression systems are installed to:

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3 Fire detection, alarm, and suppression systems are installed to: Notify occupants to escape a fire Summon emergency responders Initiate suppression systems Supervise suppression systems for operational status Initiate environmental and utility controls

4 Fire fighters must understand the various types of fire protection systems which may be encountered in different occupancies and How these systems function Their role when these systems function in an emergency

5 TYPES OF ALARM SYSTEMS PROTECTED PREMISES FIRE ALARM SYSTEMS LOCAL FIRE ALARM SYSTEM Designed to be initiated manually by pull stations Designed to only alert the building's occupants Does not notify the fire department Automatic detection devices may be added to the system to detect a fire and initiate the signal

6 Respond to the thermal energy of a fire Slowest type of system to activate Activate at a predetermined temperature or when a specified temperature rate of rise occurs

7 Used in areas unoccupied or environmentally unsuitable for application of smoke detectors Typically used as a property protection device

8 Activate when heated to the rated temperature, usually 135 o F or higher In a large area, a fire could burn for some time without activating a fixedtemperature detector

9 Operate identically to fusible links or frangible bulbs used in automatic sprinkler systems To restore a fusible device/frangible bulb detector, the entire detector must be replaced Many of these devices are still in service, however, they are no longer manufactured

10 A fusible device is held in place with solder with known melting temperature When the temperature rises to the fusing temperature, the solder melts, a spring closes the contact points and initiates the alarm signal A frangible bulb may be used to hold the electrical contacts apart like a fusible link does

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12 One type is a cable with a conductive metal inner core sheathed in stainless steel tubing The core and sheathing are separated by an insulating material At a predetermined temperature, the insulation loses some of its electrical resistance The current flow between the core and sheathing increases and initiates the alarm

13 Another system uses two insulated wires with an outer covering When the rated temperature is reached, the insulation melts and the wires touch The circuit is then completed and the alarm initiated

14 Uses two metals with different heat expansion rates When heated, one metal expands faster, causing the strip to bend The deflection makes or breaks the circuit causing alarm activation Most bimetallic detector reset automatically when cooled

15 Operates on the assumption that the temperature from a fire will increase faster than normal atmospheric heating Designed to operate when the temperature rise exceeds 12 o F to 15 o F in one minute Most are reliable and not subject to false activations Automatically reset if undamaged

16 Most common type of rate-ofrise detector used Consists of a dome-shaped air chamber with a flexible metal diaphragm in the base During a fire, the air in the chamber expands faster than it can escape The expansion causes the pressure in the chamber to increase and forces the metal diaphragm against the contact points, initiating the alarm

17 Consists of an outer metallic sleeve housing two bowed struts with slower expansion rates than the sleeve When heated rapidly, the outer sleeve expands in length The tension is reduced on the inner strips causing the contacts to come together

18 SMOKE DETECTORS Typically installed in nonresidential and multifamily occupancies Detects smoke and transmits a signal to another device that sounds the alarm

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20 A beam of light is focused onto a photoelectric cell which converts the beam into an electric current When smoke obscures the light beam, the amount of current is reduced and an alarm sounds

21 When smoke enters the chamber, the light beam is refracted in all directions and strikes the photocell, activating the alarm A light beam passes through a small chamber away from the light source The light does not strike the photocell and no current is produced

22 Ionization Chamber Tiny particles and aerosols are produced during combustion These particles can be detected by devices using a small amount of radioactive material to ionize air molecules as they enter the detector

23 The ionized air particles allow an electrical current to flow between plates in the ionization chamber When smoke enters the chamber, its particles attach to the air ions making the air less conductive The decrease in current activates the alarm

24 Reacts the fastest to fire Prone to activation by sunlight, welding and other bright lights Usually positioned where other light sources are unlikely Must have an unobstructed view of the protected area Used where immediate reaction is necessary such as flammable liquid manufacturing and dispensing facilities

25 Sensitive to sunlight and usually installed in fully enclosed areas Most are designed to require flickering motion of flame to activate Virtually insensitive to sunlight Not suitable when arc welding is done

26 Used to detect the gases produced by a fire in a confined space The gases produced will vary depending on the chemical makeup of the burning fuel Will initiate an alarm more quickly than a heat detector but slower than a smoke detector Very few fire-gas detectors are used except in special occupancies

27 Combination detectors: makes detectors more responsive to fire conditions Fixed temperature/rate-of-rise heat detectors Smoke/heat detectors Smoke/fire-gas detectors Detectors have a variety of audible and visual indicating devices

28 Fire department response to alarm calls Normally a full structure fire response is dispatched to the location of a activated smoke or heat alarm If there are no signs of smoke or fire when they arrive, a fire fighter with a portable radio should go to the alarm control panel to silence the alarm so it can be further investigated

29 Fire department response to alarm calls The system must not be reset or turned off until fire fighters determine the cause of the alarm The individual assigned to the alarm panel must remain and monitor the panel in case of another alarm If a second alarm sounds, the Incident Commander should be immediately notified

30 AUTOMATIC ALARM SIGNALING SYSTEMS Auxiliary systems Local energy systems: used only in communities with municipal fire alarm box systems An occupancy's alarm system is directly connected to the municipal master alarm box When the occupancy's alarm activates, it trips the alarm box to which it is attached and transmits the alarm to the alarm center

31 AUTOMATIC ALARM SIGNALING SYSTEMS Auxiliary systems Shunt systems where the municipal alarm circuit extends ( is shunted ) into the protected property Parallel telephone systems Not connected to the municipal alarm system Transmits the alarm over municipally controlled telephone circuits, which are not used for any other purpose

32 AUTOMATIC ALARM SIGNALING SYSTEMS REMOTE STATION SYSTEM

33 AUTOMATIC ALARM SIGNALING SYSTEMS REMOTE STATION SYSTEM Protected Properties Public Dispatch Center

34 AUTOMATIC ALARM SIGNALING SYSTEMS PROPRIETARY SYSTEM Used for large commercial and industrial buildings, high rises, and commonly owned facilities in a single location (campus or industrial complex) Alarms are transmitted to a supervising stations where operators can call the fire department or the fire department is automatically notified

35 AUTOMATIC ALARM SIGNALING SYSTEMS PROPRIETARY SYSTEM

36 AUTOMATIC ALARM SIGNALING SYSTEMS CENTRAL STATION ALARM SYSTEM Typically a company that sells alarm services to individual customers at different properties When an alarm is received, central station employees initiate an appropriate emergency response

37 AUTOMATIC ALARM SIGNALING SYSTEMS CENTRAL STATION ALARM SYSTEM Central Station Center Protected Properties Public Dispatch Center

38 Fire alarm systems are designed to be self-supervising A distinct trouble signal is generated anytime the system is not operating normally, such as when: A utility power outage occurs and the system switches to battery power A break in a detector or notification circuit occurs

39 Older systems use closed, supervised circuits where a tiny current always flows Newer systems microprocessors do an internal diagnostic system test at specified intervals Alarm signals must be distinctively different from trouble signals

40 Some fixed suppression systems depend on a signal from a manual pull station or an automatic detection device Alarm systems must also be addressable, indicating the location of an activated detector or pull station or a trouble signal

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42 Consists of a series of sprinkler heads arranged to automatically apply water directly on a fire to either extinguish it or control it until fire fighters arrive

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44 Complete system: protects an entire building Partial system: protects only certain areas, such as high hazard areas and exit routes

45 Factors affecting sprinkler system reliability and performance: Partially or completely closed valves Poor or improper maintenance Improper design Hazards of the occupancy Distribution obstructions Deficient water supply Partial sprinkler protection Frozen or broken pipes Damaged or painted sprinkler heads Tampering or vandalism

46 Properly operating sprinkler systems: Improve the life safety of a building's occupants by applying water when a fire is relatively small Prevent vertical fire spread in multistory buildings Protect occupants in other parts of a building from fire spread

47 Sprinklers alone may not be as effective if: Fires are too small to activate the sprinkler system Smoke reaches the occupants before the system activates Sleeping, intoxicated, or handicapped people occupy the building

48 SPRINKLER SYSTEM COMPONENTS Water Supply Public water systems

49 SPRINKLER SYSTEM BASIC PIPING Cross Main Branch lines: piping on which sprinkler heads are installed Riser: larger vertical piping Supply Main

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51 Temperature ratings: may be identified by color-coded frame arms, colored liquid, or temperature stamped into the head 135 o to 170 o : uncolored or black 175 o to 200 o : white 250 o to 300 o : blue 325 o to 375 o : red

52 Temperature ratings: Frangible bulbs 135 o to 170 o : orange or red glass bulb 175 o to 200 o : yellow or green bulb 250 o to 300 o : blue bulb 325 o to 375 o : purple bulb

53 Fusible Link Frangible Bulb Chemical Pellet Quick-Response

54 FUSIBLE LINK OPERATION Two lever arms press against the frame arms and valve cap to hold back the water The fusible link holds the levers together The link melts or fuses when exposed to heat and the water pushes the levers and cap out of the way Water strikes the deflector and becomes a spray

55 FRANGIBLE BULB OPERATION The bulb filled with liquid and a bubble holds the orifice shut Heat expands the liquid until the bubble is absorbed by the liquid The increase in internal pressure shatters the bulb and the orifice opens Water strikes the deflector and becomes a spray

56 SPRINKLER HEAD POSITIONS Extends down from the underside of the piping Sidewall Sits on top of Extends the from piping the side of the pipe and has a special deflector to create a fan-shaped pattern

57 A storage cabinet for extra heads and a wrench should be installed near the sprinkler system Normally holds minimum of six extra heads

58 CONTROL INDICATOR VALVES Located between water source and sprinkler system to shut off water supply Visually show if opened or closed Has a yoke on the outside with a threaded stem which controls the valve gate Threaded stem is out of yoke when open

59 CONTROL INDICATOR VALVES Post Indicator Valve (PIV) Valve stem inside of hollow post Has small window on post where OPEN or SHUT displayed

60 CONTROL INDICATOR VALVES Wall Post Indicator Valve (WPIV) Similar to PIV but extends through wall Post Indicator Valve Assembly (PIVA) Has a sight area that is open when the valve is open

61 OPERATING VALVES Alarm test valve: simulates activation of the system Main drain valve: to drain water from the system for maintenance Inspector's test valve: equipped with a same size opening as a sprinkler head to simulate activation of a head

62 WATER FLOW ALARMS Hydraulically Operated To alert occupants and a passerby that water is flowing through the system

63 WATER FLOW ALARMS Electrically Operated Alerts occupants and transmits an alarm that water is flowing through the system

64 FIRE DEPARTMENT CONNECTION (FDC) A check valve is located between the FDC and the system to prevent water from the system flowing into the FDC Usually a clappered siamese with at least two 2½ female connections

65 FIRE DEPARTMENT SUPPORT Supply pumper should have a capacity of at least 1,000 gpm Using same water main as that supplying system will rob the sprinkler system of water

66 FIRE DEPARTMENT SUPPORT A minimum of two 2 1 / 2 or larger lines should be attached to the FDC Most sprinkler systems are supplied at 150 psi

67 Wet Pipe Systems Used in locations not subject to freezing Contain water under pressure at all times Sprinkler heads discharge water immediately on activation Usually equipped with an alarm check valve on the main riser

68 Newer systems may have a backflow prevention check valve and electronic flow alarm instead of an alarm check valve ( straight stick systems ) Maybe equipped with a retard chamber to catch excess water that may come through the alarm valve in a water pressure surge

69 Wet Pipe Systems Gauges Installed above and below each alarm check valve Riser pressure gauge showing pressure in system Owner or owner's representative should check and record monthly to ensure normal water supply pressure

70 Dry Pipe Systems Used in areas subject to freezing Contains air under pressure instead of water When a sprinkler head opens, air leaves piping and dry-pipe valve automatically opens to fill the system with water

71 Dry Pipe Systems Gauges One on water side and another on the air side of dry pipe valve and at the air pump supplying air Owner should check and record gauge readings weekly to ensure normal air and water pressures are being maintained

72 Used in properties to prevent water damage, even if pipes are broken System pipes are dry until water is released into system in response to detectors Uses a deluge type valve, fire detection devices, and closed sprinkler heads Sprinkler heads open only from functioning of fusible links

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74 RESIDENTIAL SYSTEMS Used to prevent fire involvement in area of origin and allow occupants to escape Typically equipped with quick-response sprinkler heads May be wet or dry system May use plastic or steel piping

75 Whenever possible, pumpers supplying hose streams should operate from mains other than that supplying system Control valves should not be closed until fire has been extinguished unless the incident commander determines need to prevent further damage

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77 Restoring the system to service should be done by representatives of the owners or a commercial sprinkler service company

78 CONTROL OF WATER FLOW FROM SPRINKLERS Remove sprinkler wedge or clamp from apparatus Raise ladder under activated head Insert wedge or clamp into flowing head Gently tap wedge in place to stop flow

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80 Class I For use by fire fighting personnel Have 2 1 / 2 -inch hose connections attached to standpipe risers Class II Have 1 1 / 2 -inch single jacket hose with a lightweight nozzle attached Designed for use by building occupants with no fire training

81 Class III Have 2 1 / 2 -inch hose connections and 1 1 / 2 -inch single jacket linen hose with a lightweight nozzle attached Designed for use by building occupants or fire fighters

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