1 Fire Detection, Protection, and Suppression Systems (Fire Fighter II)© Ocean/Corbis CHAPTER 37 Fire Detection, Protection, and Suppression Systems (Fire Fighter II) 1
2 Fire Fighter II ObjectivesDescribe the basic components and functions of a fire alarm system. Describe the basic types of fire alarm initiation devices and indicate where each type is most suitable. 2
3 Fire Fighter II ObjectivesDescribe the fire department’s role in resetting fire alarms. Describe the basic types of alarm notification appliances. Describe the basic types of fire alarm annunciation systems. 3
4 Fire Fighter II ObjectivesExplain the different way that fire alarms may be transmitted to the fire department. Identify the four types of sprinkler heads. Identify the different styles of indicating valves. 4
5 Fire Fighter II ObjectivesDescribe the operation and application of the following types of automatic sprinkler systems: wet-pipe system, dry-pipe system, preaction system, and deluge system. Describe the differences between commercial and residential sprinkler systems. 5
6 Fire Fighter II ObjectivesIdentify the three types of standpipes and point out the differences among them. Describe two problems that fire fighters could encounter when using a standpipe in a high- rise building. 6
7 Fire Fighter II ObjectivesIdentify the hazards that specialized extinguishing systems can pose to responding fire fighters.
8 Introduction Fire prevention and building codes require that most new structures have some sort of fire protection system installed. Understanding how these systems operate is important for fire fighter safety and effective customer service. 8
9 Introduction From a safety standpoint:The operations and limitations of fire detection and suppression systems From a customer service standpoint: Help dispel misconceptions about fire protection systems. Advise building owners and occupants after an alarm is sounded. 9
10 Introduction “False alarms”Sensors record an error somewhere in the system Detectors too close to the kitchen People become used to nuisance alarms and fail to respond accordingly 10
11 Fire Alarm and Detection SystemsA fire detection system recognizes when a fire is occurring and activates the fire alarm system. Alerts occupants May alert the fire department May automatically activate fire suppression systems 11
12 Fire Alarm and Detection SystemsFire alarm and detection systems can be very simple or very complex. These systems generally have the same basic components. 12
13 Fire Alarm System ComponentsThree basic components in a fire alarm system: Alarm initiation device Alarm notification device Control panel 13
14 Fire Alarm System Control PanelsServes as the “brain” of the system Manages and monitors the proper operation of the system Can indicate the source of an alarm Also manages primary power supply and provides backup power supply for the system 14
15 Fire Alarm System Control PanelsMay perform additional functions May interface with other systems Vary greatly Courtesy of Honeywell/Gamewell 15
16 Fire Alarm System Control PanelsUsed to silence alarm and reset system Many buildings have a remote annunciator In some systems, a battery will automatically activate when the external power is interrupted. 16
17 Residential Fire Alarm SystemsSingle-station smoke alarm most common type of residential fire alarm system Includes both a smoke detection device and an audible alarm within a single unit Courtesy of Kidde Residential and Commercial Division 17
18 Residential Fire Alarm SystemsSmoke alarms can be battery powered or hard- wired to a 110-volt electrical system. Up-to-date codes require a smoke alarm in every bedroom and on every floor level. Many home fire alarm systems are part of security systems. 18
19 Ionization Versus Photoelectric Smoke DetectorsIonization detectors are triggered by the invisible products of combustion. Photoelectric detectors are triggered by the visible products of combustion. 19
20 Ionization Versus Photoelectric Smoke DetectorsCourtesy of Kevin Reed © Brendan Byrne/age fotostock 20
21 Alarm-Initiating DevicesComponents that activate a fire alarm system Manual initiation devices require human activation. Automatic devices function without human intervention. 21
22 Manual Initiation DevicesDesigned so that building occupants can activate the fire alarm system Primary manual initiation device is the manual fire alarm box or manual pull- station. © rob casey/Alamy Images Courtesy of Honeywell/Fire-Lite Alarms 22
23 Double-Action Pull StationsDesigned to prevent malicious false alarms, is covered with a piece of clear plastic Often used in areas where malicious false alarms frequently occur Courtesy of STI-USA 23
24 Automatic Initiating DevicesDesigned to function without human intervention Can use several different types of detectors Some detectors activated by smoke or by invisible products of combustion Others react to heat, light produced by an open flame, or specific gases. 24
25 Smoke Detectors Designed to sense the presence of smokeMost common are ionization and photoelectric detectors. 25
26 Heat Detectors Can provide property protectionUsed where smoke alarms cannot be used Often installed in unheated areas Generally very reliable and less prone to false alarms than smoke alarms 26
27 Fixed Temperature Heat DetectorsDesigned to operate at a preset temperature Usually use a metal alloy that will melt at the preset temperature Courtesy of Firetronics Pte Ltd. 27
28 Rate-of-Rise Heat DetectorsWill activate if air temperature rises more than a set amount in a given period. Most are self- restoring Generally respond faster to most fires than fixed-temperature heat detectors 28
29 Line Heat Detectors Use wires or a sealed tube to sense heat Wire-typeTwo wires separated by insulating material, or Measures changes in electrical resistance of a wire as it heats up Tube-type Has a sealed metal tube filled with air 29
30 Flame Detectors Specialized devices that detect the electromagnetic light waves produced by a flame Complicated and expensive 30
31 Gas Detectors Calibrated to detect the presence of a specific gasNeed regular calibration Usually found only in specific commercial or industrial applications Most common is carbon monoxide detector 31
32 Air Sampling DetectorsContinuously capture air samples and measure the concentrations of specific gases or products of combustion 32
33 Residential Carbon Monoxide DetectorsSound a visible alarm when concentration is high enough to pose health risk Must be investigated by personnel who can detect gas All occupants must be checked for carbon monoxide poisoning. 33
34 Alarm Initiation by Fire Suppression SystemsSystem alerts building occupants and the fire department to a possible fire. Ensures that someone is aware water is flowing in case of an unin- tentional discharge 34
35 False, Unwanted, and Nuisance AlarmsMalicious false alarms Individuals deliberately activate a fire alarm Unwanted alarms Alarm is activated by a condition that is not really an emergency Nuisance alarms Improper functioning of an alarm system 35
36 Alarm Notification AppliancesProduce an audible signal when fire alarm is activated Some signals play a recorded announcement in conjunction with the temporal-3 pattern. Courtesy of Honeywell/Fire-Lite Alarms 36
37 Alarm Notification AppliancesMany new systems incorporate visual notification devices. 37
38 Other Fire Alarm FunctionsMay also control other building functions, such as air-handling systems, fire doors, and elevators Responding fire personnel must understand which building functions are being controlled by the fire alarm. 38
39 Fire Alarm Annunciation SystemsZoned system Alarm control panel will indicate where in the building the alarm was activated. Coded system Zone is identified at alarm control panel and through audio notification device. 39
40 Noncoded Alarm System No information indicating where in the building the fire alarm was activated Typically sounds a bell or horn Fire department personnel must search the entire building to find which initiation device was activated. 40
41 Zoned Noncoded Alarm SystemMost common type of system, particularly in newer buildings Building divided into multiple zones, often by floor or by wing Alarm control panel indicates in which zone the activated device is located. 41
42 Zoned Coded Alarm In addition to having all the features of a zoned alarm system, also indicates which zone has been activated over the announcement system Hospitals often use this type of system. 42
43 Master-Coded Alarm Audible notification devices for fire alarms also are used for other purposes. Most of these systems have been replaced by modern speaker systems that use the temporal-3 pattern fire alarm signal and have public address capabilities. 43
44 Fire Department NotificationFire alarm systems can be broken down into five categories based on how the fire department is notified of an alarm: Local alarm system Remote station system Auxiliary system Proprietary system Central station 44
45 Fire Department NotificationLocal alarm system Does not notify the fire department The alarm sounds only in the building to notify the occupants. 45
46 Fire Department NotificationRemote station system Sends signal directly to fire department or to another monitoring location via a telephone line or a radio signal Auxiliary system Building’s fire alarm system is tied into a master alarm box located outside. 46
47 Fire Department NotificationProprietary system Building’s alarms are connected directly to monitoring site owned and operated by building owner. 47
48 Fire Department NotificationCentral stations Third-party, off-site monitoring facility An activated alarm transmits a signal to the central station by telephone or radio. Personnel notify the appropriate fire department. Courtesy of Doug Beaulieu. 48
49 Fire Suppression SystemsInclude automatic sprinkler systems, standpipe systems, and specialized extinguishing systems, such as dry chemical systems Understanding how these systems work is important because they can affect fire behavior. 49
50 Automatic Sprinkler SystemsIn most automatic sprinkler systems, the sprinkler heads open one at a time as they are heated to their operating temperature. One of the major advantages of a sprinkler system is that it can function as both a fire detection system and a fire suppression system. 50
51 Automatic Sprinkler System ComponentsFour major components: Automatic sprinkler heads Piping Control valves A water supply, which may or may not include a fire pump 51
52 Automatic Sprinkler HeadsWorking ends of a sprinkler system Composed of: A body including the orifice (opening) A release mechanism A deflector that directs the water in a spray pattern 52
53 Fusible Link Sprinkler HeadsUse a metal alloy that melts at a specific temperature Alloy links two other pieces of metal that keep the cap in place. When designated operating temperature is reached, the cap is released. 53
54 Frangible Bulb Sprinkler HeadsUse a glass bulb filled with glycerin or alcohol to hold the cap in place As bulb is heated, liquid absorbs the air bubble and expands until it breaks the glass, releasing the cap. 54
55 Chemical-Pellet Sprinkler HeadsUse a plunger mechanism and a small chemical pellet to hold the cap in place Pellet will liquefy at a preset temperature. When pellet melts, liquid compresses the plunger, releasing the cap and allowing water to flow. 55
56 Special Sprinkler HeadsDesigned for special applications Early-suppression, fast-response sprinkler heads have improved heat collectors to speed up response and ensure rapid release. 56
57 Deluge Heads Easily identifiable because they have no cap or release mechanism Orifice is always open. Only used in deluge sprinkler systems Courtesy of Tyco Fire & Building Products 57
58 Temperature Ratings Typical rating in a light hazard occupancy would be 165ºF (74ºC). Temperature rating must match the anticipated ambient air temperatures. Spare heads that match those used in the system should always be available on site. 58
59 Mounting Position Courtesy of Tyco Fire & Building Products 59
60 Sprinkler Piping Network of pipes that delivers water to sprinkler heads Usually made of steel Plastic pipe sometimes used in residential systems © ImageState/Alamy Images 60
61 Valves Sprinkler system includes several valves:Main water supply control valve Alarm valve Other, smaller valves used for testing and service Play a critical role in the design and function of the system 61
62 Water Supplies Water may come from municipal water system, on-site storage tanks, or static water sources. Preferred source for a sprinkler system is a municipal water supply. 62
63 Fire Pumps Used when the water comes from a static sourceMay also be used to boost the pressure in some sprinkler systems, particularly for tall buildings 63
64 Fire Department Connection (FDC)Allows the department’s engine to pump water into the sprinkler system Used as either a supplement or the main source of water 64
65 Water Flow Alarms Water-motor gong.When system is activated and main alarm valve opens, water is fed through a pipe to a water- powered gong located outside the building. 65
66 Types of Automatic Sprinkler SystemsDivided into four categories: Wet sprinkler systems Dry sprinkler systems Preaction sprinkler systems Deluge sprinkler systems 66
67 Wet Sprinkler Systems Most common and the least expensive type of automatic sprinkler system Piping always filled with water. As sprinkler head activates, water is immediately discharged onto the fire. Major drawback: Cannot be used in areas where temperatures drop below freezing 67
68 Dry Sprinkler Systems Operate much like wet sprinkler systems, except that the pipes are filled with pressurized air instead of water A dry-pipe valve keeps water from entering the pipes until the air pressure is released. 68
69 Dry Sprinkler Systems 69
70 Preaction Sprinkler SystemsSimilar to a dry sprinkler system with one key difference: A secondary device must be activated before water is released into the sprinkler piping. When the system is filled with water, it functions as a wet sprinkler system. 70
71 Deluge Sprinkler SystemsWater flows from all of the sprinkler heads as soon as the system is activated. Does not have closed heads that open individually at the activation temperature; all of the heads in a deluge system are always open. 71
72 Deluge Sprinkler Systems72
73 Residential Sprinkler SystemsRelatively new Typically use smaller piping and sprinkler heads with smaller orifices and less water discharge Reduce fire death by 82% © AbleStock. © AbleStock 73
74 Standpipe Systems Network of pipes and outlets for fire hoses to provide water for firefighting purposes Usually used in high- rise buildings, although they are found in many other structures as well. 74
75 Class I Standpipes Designed for use by fire department personnel onlyEach outlet has a 2½" (6.35-cm) male coupling and a valve to open the water supply after the hose is connected. © Stephen Coburn/ShutterStock, Inc. 75
76 Class II Standpipes Outlets generally equipped with a length of 1½" (3.81-cm) single- jacket hose preconnected to the system. Intended to enable occupants to attack a fire Courtesy of Ralph G. Johnson (nyail.com/fsd) 76
77 Class III Standpipes Have the features of both Class I and Class II standpipes in a single system Have 2½" (6.35-cm) outlets for fire department use as well as smaller outlets with attached hoses for occupant use 77
78 Water Flow in Standpipe SystemsFlow-restriction devices or pressure-reducing valves often installed at outlets to limit pressure and flow If not properly installed and maintained, these devices can cause problems for fire fighters. 78
79 Water Supplies Wet standpipe systems are connected to a public water supply with an electric or diesel fire pump to provide pressure. Most dry standpipe systems must use the FDC to pump water into the system. 79
80 Specialized Extinguishing SystemsSpecialized extinguishing systems are often used in areas where water would not be an acceptable extinguishing agent. 80
81 Dry Chemical Extinguishing SystemsFinely powdered agents Agent kept in self- pressurized tanks or in tanks with an external cartridge of carbon dioxide. 81
82 Wet Chemical Extinguishing SystemsUsed in most new commercial kitchens Use a proprietary liquid extinguishing agent Much more effective on vegetable oils than the dry chemicals used in older kitchen systems 82
83 Initiation Devices Fusible links are placed above the target hazard.Manual discharge button also provided so that workers can activate the system if they discover a fire. 83
84 Clean Agent Extinguishing SystemsInstalled in areas where computers or sensitive electronic equipment are used or where valuable documents are stored Nonconductive and leave no residue Halogenated agents or carbon dioxide are generally used. 84
85 Clean Agent Extinguishing SystemsShould be completely discharged before fire fighters arrive Should be tied to building’s fire alarm system and indicated as a zone on the control panel 85
86 Carbon Dioxide Extinguishing SystemsDesigned to protect a single room or series of rooms Should be connected to fire alarm system Creates oxygen- deficient atmosphere Courtesy of Chemetron Fire Systems 86
87 Summary Fire protection systems include fire alarms, automatic fire detection, and fire suppression systems. Fire alarm and detection systems range from simple to complex. A fire alarm system has three basic components. 87
88 Summary The most common residential alarm system is a single-station smoke alarm. There are two types of fire detection devices used in a smoke alarm to detect combustion. Alarm initiation devices begin the fire alarm process manually or automatically. 88
89 Summary There are nine types of automatic initiation devices.Residential carbon monoxide detectors create an audible or visual alarm. It is important to know how to handle false, unwanted, and nuisance alarms. There are three types of false alarms. 89
90 Summary There are two methods that can be used to reduce unwanted and nuisance alarms. Alarm communication systems are classified into four categories. There are five categories of fire department notification systems. 90
91 Summary Fire suppression systems include sprinkler systems, standpipe systems, and specialized extinguishing systems. The most common fire suppression system is the automatic sprinkler system. Basic operating principles of an automatic sprinkler system are simple. 91
92 Summary Automatic sprinkler systems include four major components.Automatic sprinkler systems are divided into four categories.
93 Summary There are three types of standpipe systems.Specialized extinguishing are installed in areas where water may not be used.