In order that a fire takes place, there has to be :-

In order that a fire takes place, there has to be :-

Oxygen to sustain combustion.
•Heat to raise the material to its ignition temperature.
• Oxygen to sustain combustion.
•Fuel or combustible material.
A combination of ‘all’ of the above creates a fire!!
• Heat to raise the material to its ignition
temperature.
• Fuel or combustible material.
A combination of ‘all’ of the above creates a fire!!

A chemical that is likely to burn or support fire..

The materialistic society as per the western concept has brought out huge
industrialization which is totally based on fuel consumption and energy
utilization.

Most of the energy utilization processes are hazardous, especially fire based,
electrical and fuel burning processes.
FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION
BUILDING SERVICES-III
Fire hazards are generally categorized into four groups:
I. Ignition Sources,
II. Materials,
III. Building Hazards and, most importantly, (
IV. Personnel Hazards.

All forms and types of energy can be considered a potential ignition

source. Some frequent types of ignition sources found in industry are:
• Open flames Friction
• Electrical wiring / devices Sparks and Arcs
• Smoking
• Static sparks
• Welding and cutting
• Chemical reactions
• Gas Compression
• Heat / Hot surfaces

FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
There are few materials that will not ignite and burn. Materials in a liquid, gas,
or vapor state are typically more ignitable than solid fuels.
Materials are rate by their combustibility and their ability to ignite and burn.
Information is readily accessible to determine a materials-combustibility rating.
Some common types of combustible materials found in industry are:
Wood Paints
Solvents Cloth
Cleaning fluids Plastics
Hydraulic fluids Fuels

FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
Fire can spread rapidly through a building, causing major structural failure of
roofs and walls. Depending on a building's design, fires can travel horizontally
and vertically. Listed below are examples of how fire can travel throughout a
building: •The building's structural materials will
determine its ability to withstand a fire.
•Doorways •Structural framing of wood is considered to
have a limited resistance to fire.
•Hallways
•Steel members are subject to significant
•Ceiling spaces structural decreases at low fire
•Floor spaces temperatures unless they are protected by
•Utility openings enclosures or treated with fire-resistive
chemical coatings
•Conveyor shafts

•Stairways
•Elevator shafts
•Material shafts
•Utility openings
•Conveyor shafts
FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
 :
The primary fire hazards to personnel are escape routes to safety. The following
considerations must be examined in determining the best methods of escape:

•Travel distance to an exit

•Illumination of exiting paths
•Number and arrangement of exits
•Identification of exits
•Exit pathways
•Exit doors
•Exit capacities
Stairwells

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BUILDING SERVICES-III
•Electrical systems that are overloaded, resulting in hot wiring
or connections, or failed components.
•Combustible storage areas with insufficient protection.
•Candle.
•Smoking (Cigarettes, cigars, pipes, lighters, etc.).
•Equipment that generates heat and utilizes combustible
materials.
•Flammable liquids.
•Fireplace chimneys not properly or regularly cleaned.
•Cooking appliances - stoves, ovens.
• Heating appliances - wood burning stoves, furnaces, boilers,
and portable heaters.
•Electrical wiring in poor condition.
•Batteries.
•Personal ignition sources - matches, lighters.
•Exterior cooking equipment.
•Campfires.
FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
The goal of a fire hazards analysis (FHA) is to determine the expected outcome
of a specific set of conditions called a fire scenario.
The scenario includes details of the room dimensions, contents, and materials
of construction; arrangement of rooms in the building; sources of combustion
air; position of doors; numbers, locations, and characteristics of occupants.

Hazard analysis can be used for two purposes.

•Hazards that are Present in an existing or planned facility
• The other use is for design, where trial design strategies.
are evaluated to determine whether they achieve a set of fire safety goals

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BUILDING SERVICES-III
There have been numerous studies completed of human behaviour in fire
conditions conducted . A general finding is that occupant and occupancy
characteristics can vary significantly among a variety of different building uses –
examples of such characteristics are given below;
Building population and density, Groups or lone individuals, Building familiarity,
Distribution and activities, Alertness, Physical/cognitive abilities, Role/
responsibilities, Ccommitment to task, Focal point, Gender, Culture, Age
Prior fire/evacuation experience.
These aspects of human behaviour affect both occupants' recognition of, and
response to, fire cues and their ability to affect an evacuation.
During cue validation, our brain will process all information as follows:

FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
 There are three key areas to be considered, when human
behavior related to fire:
•Behaviors that cause or prevent fires;
•Behaviors that affect fires; and
•Behaviors that increase or reduce harm from fires.

The critical human responses or behaviors that contribute to the

evacuation process. The time delay associated with cue validation
will depend on the variety of characteristics of the evacuation scenario, such as the
occupancy type, the nature of warning systems, the evacuation procedures and the
nature and number of cues given at the time of a fire.
The principals of human behaviour are listed that address the importance and potential
impact of the time delay.
• Deaths in large scale fires attributed to "panic" are far more likely to have been caused
by delays in people receiving information about a fire.
•Fire alarms cannot always be relied upon to move immediately to safety.
•The „start-up‟ time (i.e. people's response to an alarm) can be more important than the
time it takes to physically reach an exit.
•Much of the movement in the early stages of fires is characterized by activities such as
investigation, rather than escape.
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BUILDING SERVICES-III
Most of the deaths due to fire are happening either by direct burning, smoke
etc.the other reasons may be by heart failure, direct jumping from high floors
etc.The death is caused by following reasons:
•Smoke
•burning
•Panic
•vision obscurity due to smoke
•Toxic gases and vapour
•Psychological disorder

FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
The design fire curve

DO NOT WASTE TIME FOR

MAKE EXIT TO GROUND LEVEL COLLECTING VALUABLES
INSTEAD OF TERRACE
DO NOT RUN

L I F TIF POSSIBLE, USE FIRE

EXTINGUISHER
INFORM FIRE BRIGADE
DO NOT PANIC DO NOT USE LIFT TO ABOUTFIRE
ESCAPE ALERT NEIGHBOURS
FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
Fire protection is the study and practice of mitigating the unwanted effects of
potentially destructive fires. It involves the study of the behavior,
compartmentalization, suppression and investigation of fire and its related
emergencies, as well as the research and development, production, testing and
application of mitigating systems.

Fire safety of buildings in wider perspective is deemed to cover the following

aspects:
•Fire prevention/protection means.
•Fire fighting and extinguishing methods.
•Fire salvage operations.

Fire safety aspects are of two types:

•Passive fire prevention/protective means
•Active fire prevention/protective means

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BUILDING SERVICES-III
Passive protection are those which are taken care –off during designing of a
building structure and does not need any energy consumption. They directly
affect the architecture and construction value of a building. Such means
envisage the methods of assembling the components of the building in such a
way as to achieve a structure in which spread of fire is limited to barest
minimum. Following passive fire safety aspects are to be taken care of:
1)Internal hazard
i. The fire resistance of building structure.
ii. Fire integration of building
iii. Compartmentation
iv. Fire and smoke venting for smoke extraction.
2) Personal hazard the internal means of evacuation
3) Exposure hazard
i. Isolation from neighboring structures.
ii. Access for outside emergency services
iii. site planning

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BUILDING SERVICES-III
This is very much dependent on :

• Size, Shape and height.

• Material and design of construction
• Contents of the building
• Behavior of occupants

Internal hazard concerns damage or destruction of the building and influences

directly personal hazard. The internal hazard is directly related to fire load,
which in turn, enables the building to be graded when considered along with the
duration of the fire.

Structural precautions aid in giving a building the necessary to a complete burn

out and restrict any spread of fire and also minimize the personal hazard.

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BUILDING SERVICES-III
More provisions for escape of the population of a building when fire is vital and
all routes shall be constructed to ensure that the population reaches a place of
safety in the shortest period of time, without undue hindrance by smokes,
fumes, debris etc.

The aim of compartmentation is to contain

the fire within the building to minimum area.
Several types of compartmentation exist:
• Partitioning of buildings by fire resistant walls designed to stop a fire
spreading. In general, floors form the principal element of compartmentation.
• Compartmentation of buildings with a particularly high risk of fire.
• Permanent protection of exit routes inside the building (corridors, stairs,
landings) against penetration by fire.
• Compartmentation of ducting and air space linking several different areas
of the building. This is a rather complex problem in view of the range of
techniques involved(lifts, ducting for fluids, air shaft etc).

BUILDING SERVICES-III
Following points must be taken care of while planning access ways:
•The access and manoeuvring roads for fire engines.
•The facades which must be accessible from these roads depending on
•The number of occupants in the building
•The height of the building(less or more than 8m)
•Its interior design(compartmented or in zone)

In the site planning, following work stations should be kept in isolation with
respect to, are buildings as they involve special fire risks
•Garage areas
•Loading bays
•Water disposal areas
•Areas containing central heating plant
•Fuel stores
•Areas containing refrigeration plant other than small units and display cabinets
•Medium and high voltage transformers
•Ventilation plant rooms
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. Since 1971, the Chennai Metropolitan Area (CMA) has doubled million.

Passive fire protection is the primary measures integrated within the fabric
of a building to provide fire safety by responding against flame, heat and
smoke. Passive fire protection attempts to contain fires or slow the spread,
through use of fire-resistant walls, floors, and doors etc.
The choice of building materials and how they are used to provide the required level of passive fire
control depends on two factors - their „reaction to fire‟ and their „fire resistance‟.
Reaction to fire performance is a measure of the extent to which internal surfaces will contribute to
the spread of flame. The main aim is to ensure that fire will not spread with dangerous rapidity over
wall or ceiling surfaces, particularly in circulation spaces.
The fire resistance requirements for individual building elements relate to integrity and insulation.
the aim is to restrict the spread of fire from one space to another and prevent collapse. It is
particularly important that any construction used to protect escape and fire access routes has the
necessary fire resistance.
Smoke ventilation system:

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BUILDING SERVICES-III
Systems which require a certain amount of motion/or action in order to work
properly. Some of these actions could be slowing the progress of the fire,
putting out the fire, or notifying of the fire and smoke conditions.
Fire suppression systems and fire detection systems together forms active fire
protection system.
The active fire security methods can be in general divided in following heads:
•Portable fire extinguishes
•Fixed first-aid fire fighting equipment like hose-reels
•Fire hydrant installations like wet risers and yard hydrant
•Manual/automatic fire detection and alarm systems
•Fixed automatic fie fighting systems
Water sprinklers and emulsifier systems
Co2 fire fighting system
Halon fire fighting systems
•Mobile fire fighting systems and fire brigades
•Dry chemical and foam installations
•Fire salvage corps
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BUILDING SERVICES-III
 Fire hydrants are used to supply a large flow of
water to fight fires .They are positioned in public
roads and within large building complexes.
The fire brigade uses the hydrant as a quick and
easy method of obtaining water from the mains
water system, instead of having to rely solely on
water tanks in tenders.

Types of Fire Hydrants.

Wet-barrel type
The wet barrel hydrant is used in areas
where freezing does not occur. The parts of
wet-barrel hydrant are:
• Operating nut - turns hydrant on and off
• Bonnet - top of the hydrant
• Barrel - main body of hydrant, contains
operating stem
• Discharge outlet - where fire hose is hooked
up to allow water to flow from hydrant
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BUILDING SERVICES-III
Dry-Barrel Type
The dry-barrel hydrant is used in areas where freezing temperatures occur.
The parts of dry-barrel hydrant are:
• Operating nut - turns hydrant on and off
• Bonnet - top of the hydrant
• Barrel - main body of hydrant, contains operating stem
• Discharge outlet - where fire hose is hooked up to allow water to flow from
hydrant

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BUILDING SERVICES-III
A fire sprinkler system is an active fire protection measure, consisting of a
water supply system, providing adequate pressure and flow rate to a water
distribution piping system, onto which fire sprinkler are connected.
A sprinkler is a device that when activated will automatically douse a fire with
water.
A glass bulb breaks with heat build up at between 60oC and 260oC depending
on the risk and location. A fire is doused with water below the sprinkler. Other
nearby sprinklers may be also activated at the same time.

Types:
Wet pipe systems
Dry pipe systems
Deluge systems
Pre-Action Systems
Foam water sprinkler systems Fire sprinkler control
Water spray valve assembly.
Water Mist systems
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BUILDING SERVICES-III
A wet pipe system is permanently charged with water,
thus water is instantaneously discharged from a
sprinkler when it actuates. This system is suitable for
premises with adequate heating or normal conditions.
Installed more often than all other types of fire
sprinkler systems.
Most reliable, because they are simple, with the only
operating components being the automatic sprinklers
and (commonly, but not always) the automatic alarm
check valve.

FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
A dry pipe system is suitable for premises where low temperatures could cause
a wet pipe system to freeze e.g. Cold Stores.
Dry pipe systems are charged with compressed air or nitrogen under pressure,
the release of which allows the water pressure to open a valve (known as a dry
pipe valve) and the water then flows into the piping system and out from the
opened sprinklers.

FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
A deluge system is sprinkler system employing
open sprinklers that are attached to a piping system
that is connected to a water supply through a valve
that is opened by the operation of a detection
system installed in the same areas as the
sprinklers.
These systems are used for special hazards where
rapid fire spread is a concern, as they provide a
simultaneous application of water over the entire
hazard.
When this valve opens, water flows into the piping
system and discharges from all sprinklers attached
thereto.
Deluge systems are used where large quantities of
water are needed quickly to control a fast-
developing fire. Deluge valves can be electrically,
pneumatically or hydraulically operated.
FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
Pre-action sprinkler systems are specialized for
use in locations where accidental activation is
undesired, such as in museums with rare art
works, manuscripts, or books; and Data Centers,
for protection of computer equipment from
accidental water discharge.
"A pre-action sprinkler system is similar to a deluge
sprinkler system except the sprinklers are closed.
The pre-action valve is normally closed and is
operated by a separate detection system.
Activation of a fire detector will open the pre-action
valve, allowing water to enter the system piping.
Water will not flow from the sprinklers until heat
activates the operating element in individual
sprinklers. Opening of the pre-action valve
effectively converts the system to a wet pipe
sprinkler system.
FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
 Pre-Action System,
Pre-Discharge

Pre-Action System,
Non Fire Pre-Action System,
Discharge

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BUILDING SERVICES-III
"A foam-water sprinkler system is a special system that is pipe-connected to a
source of foam concentrate and to a water supply. The system is equipped with
appropriate discharge devices for extinguishing agent discharge and for
distribution over the area to be protected. The piping system is connected to the
water supply through a control valve that usually is actuated by operation of
automatic detection equipment that is installed in the same areas as the
sprinklers. When this valve opens, water flows into the piping system, foam
concentrate is injected into the water,
and the resulting foam solution discharging
through the discharge devices generates
and distributes foam. Foam-water systems
shall be of the wet pipe, dry pipe, deluge,
or pre action type. These systems are
usually used with special hazards occupancies associated with high challenge
fires, such as flammable liquids, and airport
hangars

FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
"There are four different types or classes of fire extinguishers,
each of which extinguishes specific types of fire.
Fire extinguishers use a picture/labelling system to designate
which types of fires they are to be used on. Most fire
extinguishers are labelled with coloured geometrical
shapes with letter designations.
Traditionally, the labels A,B, C or D have been used to
indicate the type of fire on which an extinguisher is to be used.

The National Fire Protection Association has classified fires into four types,
determined by the materials or fuel being burned:
Type A: Fires with combustible materials as its source,
such as wood, cloth, paper, rubber, and many plastics
Type B: Fires in flammable liquids, oils, greases, tars,
oil-base paints, lacquers, and flammable gases
Type C: Fires that involve electrical equipment
Type D: Fires with ignitable metals as its fuel source
FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
Dry Powder extinguishers are usually rated for multiple
purpose use. They contain an extinguishing agent and use
a compressed, non-flammable gas as a propellant.

Water These
extinguishers
contain water and
compressed gas
and should only
be used on Class
A (ordinary
combustibles)
fires.
Foam extinguishers have a smothering affect, depriving fire
of oxygen. These type of fire extinguishers are especially
effective on Class B (flammable liquid) fires, it can also be
used on Class A (carbonaceous) fires, paper and wood.
Carbon Dioxide (CO2) extinguishers are most effective on Class B
and C (liquids and electrical) fires. Since the gas disperses quickly,
these extinguishers are only effective from 3 to 8 feet. The carbon
dioxide is stored as a compressed liquid in the extinguisher; as it
expands, it cools the surrounding air. The cooling will often cause ice
to form around the “horn” where the gas is expelled from the
extinguisher. Since the fire could re-ignite, continue to apply the
agent even after the fire appears to be out.
CLEAN AGENT FIRE EXTINGUISHER
These are suitable for A B & C Class of Fire. They are
environmental friendly. They are harmless to your electric and
other equipment. They leave no residue! Hence, they are called
„Clean Agents‟!!
HOW TO OPERATE A FIRE EXTINGUISHER. Firstly, READ the
instructions on the sticker on the extinguisher!!!!
Remember (P.A.S.S.): Pull, Aim, Squeeze, Sweep.
P - Pull the safety pin from the handle.
A - Aim the extinguisher nozzle or hose at the base of the fire.
S - Squeeze the handle to discharge the agent.
S - Sweep side to side.
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BUILDING SERVICES-III
 These are used to protect vulnerable plant and
equipment in the event of a fire. A foam spreader allows
foam to be pumped into the area through pipe work and
a foam entry box. This is used in fuel storage areas
where the location of the oil or gas tank may cause
danger in the event of a fire.
The fire brigade carry foam making equipment on tenders
so that they can connect to the inlet box in a convenient
location. Foam concentrates are mixed with water to form
a foam solution. Foam concentrates are either specific to
the fuel or chemical that they are to protect or are specific
to the type of discharge device through which the solution
will be discharged.
Foams are defined by their expansion ratios. Low-
expansion foams expand 1 to 20 times greater than their
original volume, medium-expansion foams expand 20 to
200 times greater than their original volume, and high-
expansion foams expand 200 to 2000 times greater than
their original volume.
FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
 A Hose Reel is a cylindrical spindle
made of either metal, fiber glass or
plastic and is used for storing
a hose. The most common styles of
hose reels are spring driven (which
is self retracting), hand crank, or
motor driven.
Hose reels are categorized by the A fire hose is a high-
pressure hose used
diameter and length of the hose they
to carry water or
hold, the pressure rating and the other fire retardant
rewind method. Hose reels can (such as foam) to a
either be fixed in a permanent fire to extinguish it.
location, or portable and attached to Outdoors, it is
a truck, trailer, or cart. attached either to
There are various types of hose reel a fire engine or a fire
available, recessed into wall , flush hydrant.
mounted, automatic and manual.
Indoor fire hose
FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
 (International Journal on
Engineering Performance-Based Fire Codes, Volume 6, Number 4, p.230-233, 2004)

The term "water mist" refers to fine water sprays in which 99% of the volume of the
spray is in drops with diameters less than 1000 microns. A water mist system uses water
and compressed air to generate a very fine water droplet. These systems use
significantly less water than standard sprinkler systems. They are specifically
engineered to protect special hazard applications including combustion turbines,
machinery spaces, generator enclosures and flammable liquid storage areas .

FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
The use of water mist in fire suppression, compared to the
use of gaseous agents and conventional sprinkler systems,
has demonstrated advantages including the following:
(1) no toxic and asphyxiation problems;
(2) no environmental problems;
(3) low system cost;
(4) limited or no water damage; and
(5) high efficiency in suppressing certain fires.

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BUILDING SERVICES-III
. Since 1971, the Chennai Metropolitan Area (CMA) has 3.5 to 7.0
million.

FIRE SAFETY SYSTEMS-GENERAL &SUPPRESSION

BUILDING SERVICES-III
. Since 1971, the Chennai Metropolitan Area (CMA) has.5 to 7.0
million.

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BUILDING SERVICES-III
 FIRE FIGHTING

 FIRE FIGHTING can be defined in three separate categories:

1. FIRE PROTECTION, by design features in the construction

of the building and subsequent control of human behavior.

2. FIRE DETECTION, using artificial systems or human

senses.

3. FIRE SUPPRESSION using a number of fixed or portable

systems.
ALL FIRE FIGHTING STARTS WITH THE IDEA OF WHAT IS NEEDED FOR FIRE

ALL FIRE FIGHTING STARTS BY BREAKS THE TRIANGLE

REMOVAL
REDUCE TO

o
C
OR
LESS THAN
STOPPAGE
10% OXYGEN
 FIRE DETECTION AND ALARM SYSTEMS
 A key aspect of fire protection is to identify a developing fire emergency in a
timely manner, and to alert the building's occupants and fire emergency
organizations.
 This is the role of fire detection and alarm systems. Depending on the
anticipated fire scenario, building and use type, number and type of
occupants and criticality of contents and mission, these systems can
provide several main functions:
 First, they provide a means to identify a developing fire through either
manual or automatic methods.
 Second, they alert building occupants to a fire condition and the need
to evacuate.
 Another common function is the transmission of an alarm notification
signal to the fire department or other emergency response
organization.
 They may also shut down electrical, air handling equipment or special
process operations, and they may be used to initiate automatic
suppression systems.
 FIRE DETECTION

 A fire detection system consists of the following elements:

 Human observation
 Manual fire alarms
 Automatic Fire detectors-smoke, flame, heat (gas, H2S)
 Combinations of the above
 FIRE DETECTION PRINCIPLES
MANUAL FIRE DETECTION - PULL STATIONS
 MANUAL FIRE DETECTION IS THE OLDEST METHOD OF
DETECTION. In the simplest form, a person yelling can provide
fire warning.
 In buildings, however, A PERSON'S VOICE MAY NOT ALWAYS
TRANSMIT THROUGHOUT THE STRUCTURE. FOR THIS
REASON, MANUAL ALARM STATIONS ARE INSTALLED.

 The general design philosophy is TO PLACE STATIONS WITHIN

REACH ALONG PATHS OF ESCAPE. It is FOR THIS REASON
THAT THEY CAN USUALLY BE FOUND NEAR EXIT DOORS IN
CORRIDORS AND LARGE ROOMS.

 The advantage of manual alarm stations is that, upon

discovering the fire, they provide occupants with a readily
identifiable means to activate the building fire alarm system.
 The alarm system can then serve in lieu of the shouting
person's voice.
 The key disadvantage is that they will not work when the
building is unoccupied.
 FIRE DETECTION PRINCIPLES

AUTOMATIC DETECTORS – SPOT TYPE

 SPOT TYPE DETECTOR.
 A device in which the detecting Element is concentrated at a particular
location.
 Typical examples are Bimetallic detectors, fusible alloy detectors,
certain pneumatic rate-of-rise Detectors, certain smoke detectors, and
thermoelectric detectors.
 FIRE DETECTION PRINCIPLES

AUTOMATIC DETECTORS – PHOTOELECTRIC

 In the normal case, the light from the light

source on the left shoots straight across
and misses the sensor.

 When smoke enters the chamber, however,

the smoke particles scatter the light and
some amount of light hits the sensor.

Light Obscuration Type

 In a projected Beam Detector, alarms are

generated by diffusing the projected light
beam by a specified percentage of
obscuration.

 Total beam blockage generally results in a

trouble signal.
 FIRE DETECTION PRINCIPLES

AUTOMATIC DETECTORS – FLAME

 Due to their fast detection capabilities, flame detectors are generally used
only in high-hazard areas, such as fuel-loading platforms, industrial process
areas, hyperbaric chambers, high-ceiling areas, and atmospheres in which
explosions or very rapid fires may occur.

 Because flame detectors must be able

to 'see' the fire, they must not be blocked
by objects placed in front of them.

 The infrared-type detector, however,

has some capability for detecting
radiation reflected from walls.
 FIRE DETECTION PRINCIPLES

AUTOMATIC DETECTORS – AIR SAMPLING

 Air Sampling-Type Detector. A detector that consists of a piping or tubing
distribution network that runs from the detector to the area(s) to be
protected.
 An aspiration fan in the detector draws air form the protected area back to
the detector through air sampling ports, piping, or tubing. At the detector,
the air is analyzed for fire products.
 FIRE DETECTION PRINCIPLES

 AUTOMATIC DETECTORS – FIXED TEMP.

 Fixed-temperature heat detectors are designed to alarm when the
temperature of the operating elements reaches a specific point.
 The air temperature at the time of alarm is usually considerably higher than
the rated temperature because it takes time for the air to raise the
temperature of the operating element to its set point.
 This condition is called thermal lag. Fixed-temperature heat detectors are
available to cover a wide range of operating temperatures - from about
135'F (57'C) and higher.
 Higher temperatures detectors are also necessary so that detection can be
provided in areas normally subject to high ambient temperatures, or in
areas zoned so that only detectors in the immediate fire area operate.

 Fixed-Temperature Detector. A device that responds

when its operating element becomes heated to a
predetermined level.
 FIRE DETECTION PRINCIPLES

 AUTOMATIC DETECTORS – RATE-OF-RISE

 RATE-OF-RISE DETECTOR.

A device that responds when the temperature rises at a rate exceeding a

predetermined value

 One effect that flaming fire has on the surrounding area is to rapidly
increase air temperature in the space above the fire.

 Fixed-temperature heat detectors will not initiate an alarm until the air
temperature near the ceiling exceeds the design operating point.

 The rate-of-rise detector, however, will function when the rate of

temperature increase exceeds a predetermined value, typically around
12 to 15'F (7 to 8'C) per minute.

 Rate-of-rise detectors are designed to compensate for the normal

changes in ambient temperature that are expected under non-fire
conditions.
 FIRE DETECTION PRINCIPLES

AUTOMATIC DETECTORS – COMBINATION

 Combination detectors contain more than one element which responds to

fire. These detectors may be designed to respond from either element, or
from the combined partial or complete response of both elements.

 An example of the former is a heat detector that operates on both the rate-
of-raise and fixed-temperature principles. Its advantage is that the rate-of-
rise element will respond quickly to rapidly developing fire, while the fixed-
temperature element will respond to a slowly developing fire when the
detecting element reaches its set point temperature.

 The most common combination detector uses a vented air chamber and a
flexible diaphragm for the rate-of-rise function, while the fixed-temperature
element is usually leaf-spring restrained by a eutectic metal. When the
fixed-temperature element reaches its designated operating temperature,
the eutectic metal fuses and releases the spring, which closes the contact .
 FIRE DETECTION PRINCIPLES
AUTOMATIC DETECTORS – COMBINATION
 COMBINATION DETECTOR.
 A device that either responds to more than one of the fire phenomena
or employs more than one operating principle to sense one of these
phenomena.
 Typical examples are a combination of a heat detector with a smoke
detector or a combination of rate-of-rise and fixed temperature heat
detector.
 This device has listings for each sensing method employed.
 FIRE DETECTION PRINCIPLES

 DUCT DETECTORS

 Photoelectric detector mounted in housing outside the ductwork that

has probes that extend into the duct to sample the air inside the duct.

 Primarily used as a smoke control device to control the flow of air in

ductwork.
 SPRINKLER SYSTEMS

 2 MAJOR DIFFERENT TYPES OF WATER SPRINKLER SYSTEMS

1. WET PIPE SYSTEM

2. DRY PIPE SYSTEM

WET-PIPE SYSTEMS
DRY PIPE SYSTEM
 LOCATION AND SPACING OF SPRINKLERS

 Spacing depends on the class of hazard of occupancy and the type of

ceiling construction

 Light hazard - 15' maximum between sprinklers

 Ordinary hazard - 12-15' ft. depending on use of area
 Extra hazard - 12' maximum

 Sprinklers must also be spaced so that each sprinkler does not

protect more than a specified area:

 Light hazard occupancy—floor area/sprinkler maximum of 130-200

square feet, depending on type of ceiling

 Ordinary hazard occupancy--max. area per sprinkler 100-130 square

feet, depending on use of space

 Extra hazard occupancy--90 square feet sprinkler maximum

SPRINKLER PIPING
Sprinkler Valves
The purpose of a sprinkler valve is to retain &
control flow of water and to isolate individual
risers.

TYPES OF CONTROL VALVES

OS&Y (Outside Screw and Yoke) PIV (Post Indicator Valve)
WPIV (Wall Post Indicator Valve)
 SPRINKLER HEADS

Type based on position

The different colours denote different operating temperatures, but the

alcohol is the same, only the size of the air bubble changes.
 RELEASING MECHANISMS

 Heat causes alcohol inside bulb to expand, shatter bulb and water flows.
 RELEASING MECHANISMS
 SPRINKLER DESIGNS
 HIGH FOG

A single stage low pressure centrifugal pump, with a screw inducer fitted in the
eye takes suction direct from the domestic fresh water tank.
 DRY CHEMICAL FIRE EXTINGUISHING SYSTEMS

 DRY CHEMICAL POWDER TOTAL FLOODING SYSTEM

Dry chemical fixed pipe fire suppression systems are self contained units,
designed by factory trained personnel, consisting of a pressure vessel
constructed to ASME standards, nitrogen cylinders , automatic detection
devices and electric/pneumatic manual actuation devices.
 GAS EXTINGUISHING
 FM-200® Fire Suppression agent was the first environmentally acceptable
replacement for Halon 1301.
 FM-200® has zero ozone depleting potential, a low global warming
potential and a short atmospheric lifetime. It is particularly useful where an
environmentally acceptable agent is essential, where clean up of other
media presents a problem, where weight versus suppression potential is a
factor, where an electrically non-conductive medium is needed, and people
compatibility an overriding factor.
 FM-200® is a colorless, liquefied compressed gas. It is stored as a liquid
and dispensed into the hazard as a colorless, eclectically non-conductive
vapour that is clear and does
FIRE FIGHTING FOAM PRINCIPLES AND ETHANOL-BLENDED FUEL

 Production of ethanol large & likely to continue to increase

 Predominate danger from tanker trucks & rail cars carrying large
amounts of ethanol, manufacturing facilities, & storage facilities

 Responders need to be prepared for large-scale emergencies &

prepared with most effective techniques & extinguishing media
 FOAM

 …an aggregate of air-filled bubbles formed from aqueous solutions

which is lower in density than flammable liquids.

 It is used principally to form a cohesive floating blanket on flammable

and combustible liquids, and prevents or extinguishes fire by excluding
air and cooling the fuel. It also prevents re-ignition by suppressing
formation of flammable vapors.

 It has the property of adhering to surfaces, which provides a degree of

exposure protection from adjacent fires
 Why use foam?
 Only agent capable of suppressing vapors & providing visible proof of
security .

 Foam blanket on un-ignited spill Can provide post-fire security by

protecting hazard until it can be secured / removed

 Can provide protection from flammable liquids for fire & rescue
personnel during emergency operations
 BASIC FOAM PRINCIPLES

 HOW FOAM WORKS:

Foam can:

 Exclude oxygen from fuel vapors

 Cool fuel surface with water content of foam
 Prevent release of flammable vapors from fuel surface
 Emulsify fuel
 Before being used must be proportioned & aerated

 4 elements:

1. Foam concentrate
2. Water
3. Air
4. Aeration
 WHAT IS FOAM NOT EFFECTIVE ON?
 Foam is not effective on Class C electrical fires:
 Foam contains 94–97% water & water conducts electricity
 Class C fires can be extinguished using nonconductive extinguishing
agents.
 TYPES OF FOAM:
 Protein foam
 Fluoroprotein foams
 AFFF
 FFFP
 AR foam
 Foam characteristics:

 Knockdown
 Heat resistance
 Fuel tolerance
 Vapor suppression
 Alcohol tolerance