Essentials of Fire Fighting, 5th Edition

Chapter 16 — Fire Detection, Alarm, and Suppression

Systems

Firefighter I

Firefighter I16–2

Chapter 16 Lesson Goal

• After completing this lesson, the student shall be able to operate various fire detection, alarm, and suppression systems and operate at fires in protected properties following the policies and procedures set forth by the authority having jurisdiction (AHJ).

Firefighter I16–3

Specific Objectives

1.List functions of fire detection, alarm, and suppression systems. 2.Discuss general automatic sprinkler protection and types of coverage. 3.Describe control valves and operating valves used in sprinkler systems. (Continued)

Firefighter I16–4

Specific Objectives

4.Describe major applications of sprinkler systems. 5.Discuss operations at fires in protected properties. 6.Operate a sprinkler system control valve. (Skill Sheet 16-I-1)

(Continued)

Firefighter I16–5

Specific Objectives

7.Manually stop the flow of water from a sprinkler. (Skill Sheet 16-I-2)8.Connect hoseline to a sprinkler system FDC. (Skill Sheet 16-I-3)

Firefighter I16–6

Functions of Fire Detection, Alarm, Suppression Systems

• To notify occupants of facility to take necessary evasive action to escape dangers of hostile fire

• To summon organized assistance to initiate or assist fire control activities

(Continued)

Firefighter I16–7

Functions of Fire Detection, Alarm, Suppression Systems

• To initiate automatic fire control, suppression systems, sound alarm

• To supervise fire control, suppression systems to ensure operational status maintained

(Continued)

Firefighter I16–8

Functions of Fire Detection, Alarm, Suppression Systems

• To initiate wide variety of auxiliary functions involving environmental, utility, process controls

(Continued)

Firefighter I16–9

Automatic Sprinkler Protection

• Consists of series of sprinklers arranged so system will automatically distribute sufficient quantities of water directly onto fire

• Water supplied to sprinklers through system of piping

(Continued)

Firefighter I16–10

Automatic Sprinkler Protection

• Sprinklers can extend from exposed pipes or protrude through ceiling or walls from hidden pipes

• Sprinkler coverage; complete or partial

(Continued)

Firefighter I16–11

Automatic Sprinkler Protection

• Standards used as guides for installing sprinkler protection in most occupancies

• Sprinkler system should be listed by nationally recognized testing laboratory

• Automatic sprinkler systems fail to operate only in rare instances

Firefighter I16–12

Effects of Sprinkler Systems on Life Safety

• Safety of building occupants enhanced by presence of sprinkler system because it discharges water directly onto fire while still relatively small

(Continued)

Firefighter I16–13

Effects of Sprinkler Systems on Life Safety

• Because fire extinguished/controlled in early growth stage, combustion products limited

• Sprinklers also effective in other situations

• There are times when sprinklers alone are not as effective

Firefighter I16–14

Control Valves

• Part of every sprinkler system

• Used to turn off water supply to system in order to replace sprinklers, perform maintenance, interrupt operations

(Continued)

Firefighter I16–15

Control Valves

• Located between source of water supply, sprinkler system

• Usually located immediately under sprinkler alarm valve, dry-pipe or deluge valve, or outside building near sprinkler system it controls

(Continued)

Firefighter I16–16

Control Valves

• Either secured in open position with chain and padlock or electronically supervised to make sure not inadvertently closed

Firefighter I16–17

Indicating Control Valves

• Show at glance whether open or closed

• Outside stem and yoke (OS&Y) valve

(Continued)

Firefighter I16–18

Indicating Control Valves

• Post indicator valve (PIV)

(Continued)

Firefighter I16–19

Indicating Control Valves

• Wall post indicator valve (WPIV)(Continued)

Firefighter I16–20

Indicating Control Valves

• Post indicator valve assembly (PIVA)

Firefighter I16–21

Operating Valves

• Alarm test valve• Inspector’s test valve• Main drain valve

Firefighter I16–22

Wet-Pipe Systems

• Used in locations where temperatures below 40°F (4°C) not expected

• Simplest type of automatic fire sprinkler system

(Continued)

Firefighter I16–23

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 I16–24

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 I16–25

Wet-Pipe Systems

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

Firefighter I16–26

Dry-Pipe Systems

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

(Continued)

Firefighter I16–27

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 I16–28

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 I16–29

Dry-Pipe Systems

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

Firefighter I16–30

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 I16–31

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 I16–32

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 I16–33

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 I16–34

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 I16–35

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 I16–36

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 I16–37

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 I16–38

Important Factors in Occupancies With Activated Sprinkler Systems

• Early-arriving pumper should connect to FDC in accordance with preincident plan

• Firefighters should make every effort to supply adequate water to operating sprinkler system

(Continued)

Firefighter I16–39

Important Factors in Occupancies With Activated Sprinkler Systems

• Water supply may have to be conserved to supply sprinkler system

• Sprinkler system control valves must be open

(Continued)

Firefighter I16–40

Important Factors in Occupancies With Activated Sprinkler Systems

• Sprinkler control valves should not be closed until fire officers convinced further operations will simply waste water, produce heavy water damage, hamper progress of final extinguishment

(Continued)

Firefighter I16–41

Important Factors in Occupancies With Activated Sprinkler Systems

• When a sprinkler control valve closed, firefighter with portable radio should be stationed at valve in case it needs to be reopened

• In some departments, SOP to plug open sprinklers rather than shut entire system down

(Continued)

Firefighter I16–42

Important Factors in Occupancies With Activated Sprinkler Systems

• Pumpers should not be disconnected from FDC until after extinguishment confirmed by thorough overhaul

• Sprinkler equipment should be restored to service before leaving premises

(Continued)

Firefighter I16–43

Important Factors in Occupancies With Activated Sprinkler Systems

• Firefighters may be required to stop flow of water from single sprinkler that has been activated

Firefighter I16–44

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 I16–45

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 I16–46

Review Questions

1.What are the functions of fire detection, alarm, and suppression systems?2.What are the two general types of sprinkler coverage?3.What is the function of control valves?

(Continued)

Firefighter I16–47

Review Questions

4. What is the difference between a wet-pipe system and a dry-pipe system? 5.When should sprinkler control valves be closed?