Fire protection SYSTEMS in Buildings

1. FIRE
PROTECTION
EQUIPMENTS
MUHAMMAD ASAD ZAKA
2010-BA-42
CONTACT : 0346-4410825
SUBMITTED TO SIR AHMED SALEEM
UNIVERSITY OF ENGINEERING &
TECHNOLOGY LAHORE

2. FIRE PROTECTION SYSTEMS
Fire protection systems are used in buildings depending upon the type of use of the
building. Fire suppression systems are used in conjunction with smoke
detectors and fire alarm systems to improve and increase public safety. Suppression
systems are governed by the codes under the NFPA 13 handbook.
Types
 Gaseous agents
 Wet and dry chemical agents( Foams)
 Fire sprinkler systems (wet, dry, pre-action, and deluge)
 Gaseous agents:

3. The system typically consists of the agent, agent storage containers, agent
release valves, fire detectors, fire detection system (wiring control panel,
actuation signaling), agent delivery piping, and agent dispersion nozzles. Less
typically, the agent may be delivered by means of solid propellant gas generators
that produce either inert or chemically active gas. Gaseous fire suppression is a
term to describe the use of inert gases and chemical agents to extinguish a fire.
There are four means used by the agents to extinguish a fire. They act on the
"fire tetrahedron”
 Inhibiting the chain reaction of the above components
 Reduction or isolation of fuel
 Reduction of heat
 Reduction or isolation of oxygen
Methods for applying an extinguishing agent :
 Total flooding
 Local application
i. Systems working on a total flooding principle apply an extinguishing agent to a
three dimensional enclosed space in order to achieve a concentration of the
agent (volume percent of the agent in air) adequate to extinguish the fire. These
types of systems may be operated automatically by detection and related
controls or manually by the operation of a system actuator.
ii. Systems working on a local application principle apply an extinguishing agent
directly onto a fire (usually a two dimensional area), or into the three dimensional
region immediately surrounding the substance or object on fire. The main
difference in local application from total flooding design is the absence of
physical barriers enclosing the fire space.
In the context of automatic extinguishing systems, local application normally does
not refer to the use of manually operated wheeled or portable fire extinguishers,
although the nature of the agent delivery is similar.
 Wet and dry chemical agents( Foams)
Fire-fighting foam is a foam used for fire suppression. Its role is to cool the fire
and to coat the fuel, preventing its contact with oxygen, resulting in suppression
of the combustion.
Depending on the type of foam system, this is done in several ways:

4.  Foam blankets the fuel surface smothering the fire.
 The fuel is cooled by the water content of the foam.
 The foam blanket suppresses the release of flammable vapors that can mix with
the air.
1. Class “A” foam :
Class A foams were developed in mid-1980s for fighting wildfires. Class A
foams lower the surface tension of the water, which assists in the wetting and
saturation of Class A fuels with water. This aids fire suppression and can
prevent reigniting. Favorable experiences led to its acceptance for fighting
other types of class A fires, including structure fires.
2. Class “B” foam :
Class B foams are designed for class B fires — flammable liquids (such as
nail polish and White Out). The use of class A foam on a class B fire may
yield unexpected results, as class A foams are not designed to contain the

5. explosive vapors produced by flammable liquids. Class B foams have two
major subtypes.
a) Synthetic foams :
Synthetic foams are based on synthetic surfactants. Synthetic foams provide
better flow and faster knockdown of flames, but limited post-fire security.
Aqueous film forming foams (AFFF) are water-based and frequently contain
hydrocarbon-based surfactant such as sodium alkyl sulfate,
and fluorosurfactant — such as fluorotelomers,perfluorooctanoic acid (PFOA),
or perfluorooctanesulfonic acid (PFOS). They have the ability to spread over
the surface of hydrocarbon-based liquids.
Alcohol-resistant aqueous film-forming foams (AR-AFFF) are foams resistant
to the action of alcohols, able to form a protective film when they are present.
b) Protein foams :
Protein foams contain natural proteins as the foaming agents. Unlike
synthetic foams, protein foams are bio-degradable. They flow and spread
slower, but provide a foam blanket that is more heat-resistant and more
durable.
Protein foams include regular protein foam (P), fluoroprotein foam (FP), film-
forming fluoroprotein (FFFP), alcohol-resistant fluoroprotein foam (AR-FP),
and alcohol-resistant film-forming fluoroprotein (AR-FFFP).
Protein Foam from non-animal sources is preferred because of the possible
threats of biological contaminants like prions.
 Fire sprinkler systems (wet, dry, pre-
action, and deluge)
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 sprinklers are connected. Although
historically only used in factories and large commercial buildings, home and
small building systems are now available at a cost-effective price.

6. SPRINKLING PROCESS :
Each closed-head sprinkler is held closed by either a heat-sensitive glass bulb or
a two-part metal link held together with fusible alloy. The glass bulb or link
applies pressure to a pip cap which acts as a plug which prevents water from
flowing until the ambient temperature around the sprinkler reaches the design
activation temperature of the individual sprinkler head. In a standard wet-pipe
sprinkler system, each sprinkler activates independently when the predetermined
heat level is reached. Because of this, the number of sprinklers that operate is
limited to only those near the fire, thereby maximizing the available water
pressure over the point of fire origin.
A sprinkler activation will do less damage than a fire department hose stream,
which provide approximately 900 liters/min (250 US gallons/min. A sprinkler will
usually activate between one and four minutes, whereas the fire department
typically takes at least five minutes to arrive at the fire site after receiving an
alarm, and an additional ten minutes to set up equipment and apply hose

7. streams to the fire. This additional time can result in a much larger fire, requiring
much more water to extinguish.