Chapter 12

Systems and Equipment for Fire Protection

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