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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
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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
Learning Objective 1 Components of a Water Supply System • 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 1 Components 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 1 Components of a Water Supply System • TYPES OF HYDRANTS IN USE TODAY • Wet barrel hydrant • Dry barrel hydrant • Dry hydrant • Hydrant installation • Cont.
Learning Objective 1 Components 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 2 Importance of Dependable Water Supply System • PUBLIC 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
Learning Objective 3 Components of Water Supply Program • WATER SYSTEMS PROGRAM • Letter of working agreement • Grid map • Hydrant survey and • service records • Preplanning • Cont.
Learning Objective 3 Components of Water Supply Program • WATER SYSTEMS PROGRAM • Auxiliary sources of water supply • Reservoirs • Cisterns • Swimming pools • Canals • Rivers
Learning Objective 4 Fire Detection Systems and Their Components • 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 4 Fire Detection Systems and Their Components • DETECTION SERVICES • Smoke detector • Ionization chamber detector • Flame or light detector • Visible smoke detector • Cont.
Learning Objective 4 Fire 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 4 Fire 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 5 Extinguishing Systems and Their Components • SPRINKLER SYSTEMS • Residential sprinklers • Commercial and industrial • Wet pipe system • Dry pipe system • Deluge system • Cont.
Learning Objective 5 Extinguishing Systems and Their Components • SPRINKLER SYSTEMS • Preaction sprinkler system • Sprinkler heads • Standpipe systems • Foam systems • Carbon dioxide • Cont.
Learning Objective 5 Extinguishing 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 Objectives 6 and 7 Different Types of Extinguishing Agents How Various Extinguishing Agents Work • 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 7 Different Types of Extinguishing Agents How 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 7 Different Types of Extinguishing Agents How 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 7 Different Types of Extinguishing Agents How 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 7 Different Types of Extinguishing Agents How 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 7 Different Types of Extinguishing Agents How 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 7 Different Types of Extinguishing Agents How 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)
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