As 1851-2005 Maintenance of Fire Protection Systems and Equipment
Chapter 12 Fire Protection Systems and Equipment
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Transcript of Chapter 12 Fire Protection Systems and Equipment
Chapter 12
Fire Protection Systems and Equipment
Introduction
• Water is the most common extinguishing agent used for combating fires
• Automatic firefighting devices have been developed to aid in the application of water and other firefighting agents
• In occupancies or applications where water may cause damage or be ineffective, other extinguishing agents have been developed
WATER SUPPLY SYSTEM
• All systems must have storage capability• Capacity and adequacy• Adequacy gauged in several areas
Average daily consumption Maximum daily consumption Peak hourly consumption
Learning Objective 1Components of a Water Supply System
DISTRIBUTION SYSTEM
• Underground piping called water mains• Largest are primary feeders• Intermediate are secondary feeders• Distributor piping• Common sizes are 8, 12, and 16 inch
Learning Objective 1Components of a Water Supply System
TYPES OF HYDRANTS IN USE TODAY
• Wet barrel hydrant
• Dry barrel hydrant
• Dry hydrant
• Hydrant installation
Cont.
Learning Objective 1Components of a Water Supply System
TYPES OF HYDRANTS IN USE TODAY
• Airport or special property
• Complete prefire program
• Flushing hydrants
• Hydrant testing
• Hydrant painting
Learning Objective 1Components of a Water Supply System
Learning Objective 2Importance of Dependable
Water Supply SystemPUBLIC WATER COMPANIES
• Set up under public utility laws
• Provide for everyday needs of customers
• Usually have elected officials to administrate
PRIVATE WATER COMPANIES
• Maintain their own distribution and storage equipment
WATER SYSTEMS PROGRAM
• Letter of working agreement
• Grid map
• Hydrant survey andservice records
• PreplanningCont.
Learning Objective 3Components of Water Supply Program
WATER SYSTEMS PROGRAM
• Auxiliary sources of water supply Reservoirs Cisterns Swimming pools Canals Rivers
Learning Objective 3Components of Water Supply Program
PRIVATE FIRE PROTECTION SYSTEMS
• Designed to protect individual occupancies from fire
• Private homes, businesses, manufacturing plants, or public buildings
• Main purpose is to alert occupants
• Some systems alert and extinguish
Learning Objective 4Fire Detection Systems and Their Components
DETECTION SERVICES
• Smoke detector
• Ionization chamber detector
• Flame or light detector
• Visible smoke detector
Cont.
Learning Objective 4Fire Detection Systems and Their Components
DETECTION SERVICES
• Rate of rise detector
• Fixed temperature detector
• Carbon monoxide (CO) detector
• Manual pull alarm
• Water flow switch or excess flow alarm
Learning Objective 4Fire Detection Systems and Their Components
MONITORED ALARMS
• Combination of alarms
• Must be monitored at some level
• Transmits to fire department
• Sometimes plagued with frequent false alarms
Learning Objective 4Fire Detection Systems and Their Components
SPRINKLER SYSTEMS
• Residential sprinklers• Commercial and industrial• Wet pipe system• Dry pipe system• Deluge system
Cont.
Learning Objective 5Extinguishing Systems and Their Components
SPRINKLER SYSTEMS
• Preaction sprinkler system• Sprinkler heads• Standpipe systems• Foam systems• Carbon dioxide
Cont.
Learning Objective 5Extinguishing Systems and Their Components
SPRINKLER SYSTEMS
• Dry chemical systems• Wet chemical extinguishing systems (Class K)• Fire extinguishers• Obsolete agents• Fire pumps• Pressure-reducing devices
Learning Objective 5Extinguishing Systems and Their Components
WATER
• Most common fire extinguishing agent in use today• Extinguished through cooling and smothering• Highest specific heat of any known substance• Latent heat of vaporization• Numerous delivery systems available
Learning Objectives 6 and 7Different Types of Extinguishing AgentsHow Various Extinguishing Agents Work
FOAM PROPERTIES
• Its effectiveness over plain water is becoming popular
• Properties of extinguishing fires• Components are water and foam concentrate• Traditional purpose is to
extinguish flammable liquids
Learning Objectives 6 and 7Different Types of Extinguishing AgentsHow Various Extinguishing Agents Work
CLASS B FOAM
• Forms a layer above the surface of the liquid• Chemical foams• Mechanical foams• Protein foam• Fluoroprotein foam
Cont.
Learning Objectives 6 and 7Different Types of Extinguishing AgentsHow Various Extinguishing Agents Work
CLASS B FOAM
• Alcohol-type protein foams• Aqueous film-forming foam (AFFF)
Most popular type of synthetic foam• High-expansion foams
Will reduce visibility to nearly zero
Learning Objectives 6 and 7Different Types of Extinguishing AgentsHow Various Extinguishing Agents Work
CLASS A FOAM
• Much lower concentration than class B• Can stick to vertical surfaces• Can pre-treat areas in advance• Blocking gel• Wetting agents• Fire retardant
Learning Objectives 6 and 7Different Types of Extinguishing AgentsHow Various Extinguishing Agents Work
CARBON DIOXIDE
• Extinguishes by smothering• Installed where water is not the agent of choice
HALOGENATED AGENTS• Break the chemical chain reaction• Concern about their effect on the ozone layer
Learning Objectives 6 and 7Different Types of Extinguishing AgentsHow Various Extinguishing Agents Work
CLEAN AGENTS
• Do not deplete the Earth’s ozone layer
DRY CHEMICAL• Mixture of finely divided powders
DRY POWDER• Used on combustible metals (Class D)
Learning Objectives 6 and 7Different Types of Extinguishing AgentsHow Various Extinguishing Agents Work
Summary
• The fire department should have a close working relationship with the local water company
• A thorough knowledge of the strengths and weaknesses of the water system is necessary for decision-making purposes at the fire scene
• Firefighting agents are all applied through some type of system
• Pre-plan what is necessary to support these systems in case of fire