FMT 101
Building Services
STUDY UNIT 2
Fire Protection
The Education and Research arm of the Building and Construction Authority
Lesson Objectives
1. FIRE TETRAHEDRON of combustion.
2. FIRE HYDRANT, RISERS & HOSEREEL SYSTEMS (SS 575-2012)
a) HYDRANT SYSTEM, its Provisions and Locations.
b) Types of RISING MAINS SYSTEM
• Types and their requirements in buildings.
• Breeching Inlets and their requirements.
• Functions of Landing Valves and their requirements.
3. Electrical Fire Alarm Systems (SS 645-2019)
• Components and functions
• Two (2) different types of automatic electrical fire alarm systems
➢ Conventional & Addressable (Advantages vs Disadvantages)
4. Automatic Fire Sprinkler Systems (CP 52-2004)
• Principles and operations
• Potential benefits of sprinkler systems
• System components and types of sprinkler systems
• Major components of sprinkler installation for proper operation of the systems
• Different types of sprinkler systems and their applications.
FIRE CODES &
CODE OF PRACTICE
Fire Authority & Regulatory Requirements
❖ FIRE CODES 2013
▪ Fire Code 2007 Master Version
▪ Fire Code Handbooks 2013
• https://www.scdf.gov.sg/home/fire-safety/downloads/acts-codesregulations/fire-code-2013-handbook
▪ Key Change In 2013 Code
• new fire safety features within buildings to facilitate the evacuation of
persons with disabilities during an emergency situation.
❖ FIRE CODE 2018
• https://www.scdf.gov.sg/firecode2018/firecode2018
• https://www.scdf.gov.sg/home/fire-safety/downloads/acts-codes-regulations
Fire Authority & Regulatory Requirements
Code of Practice (CP)
▪ SS 645:2019 (formerly CP 10)
• CP for Installation and Servicing of Electrical Fire Alarm Systems
▪ SS 575: 2012 (formerly CP 29)
• CP for Fire hydrant, rising mains and hose reel systems
▪ SS CP 52: 2004
• CP for Automatic Sprinkler System
▪ SS 553: 2009 (formerly CP 13)
• CP for ACMV in Buildings
Habitable height is the height measured
from the lowest level of fire engine accessway
or access road (applicable to building under purpose Group II)
to the finished floor level of the highest habitable floor.
Fire Authority & Regulatory Requirements
• Fire Safety Act (FSA)
▪ Fire Safety (Building Fire Safety) Regulations
▪ Empowerment of SCDF
• SCDF (FSSD) Regulatory & Submission
▪ Appointment of QPs
• Trained in fire safety engineering and may design
performance-based fire safety measures
Fire Authority & Regulatory Requirements
▪ Fire Safety Act (FSA)
Engagement of Professional Engineer *
• Building Owner of Public Building responsible to
engage PE
• PE to conduct tests on fire safety systems annually
• PE to ensure that systems are in good working
condition
• SCDF will issue a Fire Certificate after the PE has
certified that the systems function properly
01 FIRE TETRAHEDRON
of COMBUSTION
Fire Tetrahedron
• Basic components of a fire are:
– Fuel
– Source of ignition
– Oxygen
– Process of combustion
• Commonly referred to as the
"fire Tetrahedron"
Fire is a process in which molecules of fuel combine with molecules of
oxygen, producing gases and energy. When this happens rapidly, as in a
fire, energy is released as heat and light, and some gases become visible
as smoke.
10
Ref: Learning resource:Chapter 1 > Concept of Fire Tetrahedron
Fire tetrahedron
• Fires start when all 4 elements are
present:
– Fuel
– Oxygen
– Heat
– Sustainable Chain Reaction
e.g., gas, liquid, any
combustible
materials
another
oxidizer
• These 4 elements are called the
Fire Tetrahedron
i.e. flammable
and/or combustible
material
Fire Tetrahedron
Fire tetrahedron
• Fire can be extinguished by removing any one of the 4 elements
of the tetrahedron
– Cooling, lowering temperature, remove heat
• Application of water acts by removing heat from the
fuel faster than combustion generates it.
Heat
– Smoother Air Supply, oxygen starvation
• Putting a fire blanket to cut off the oxygen supply
Chemical
Chain
Reaction
– Remove Fuel Source
• Physically removing fuel(s)
Fuel
Oxygen
– Interrupt Reaction
• Interference of Chemical Reaction - Other gaseous fire suppression agents,
such as halon or HFC-227, interfere with the chemical reaction itself.
02 FIRE HYDRANT, RISER &
HOSEREEL SYSTEMS
02a HYDRANT SYSTEM
its PROVISIONS and
LOCATIONS
Reference:
Fire Code 2013 Handbook
Chapter 4 – SITE PLAN & EXTERNAL FIRE FIGHTING PROVISION
Location of Fire Hydrant (FH)
• Where can you find FH?
– Along The Roads
• Public Hydrants installed by the Authority
– Within The Private Compound
• Private Hydrants provided and installed by
the building owner (yellow band)
Regulatory
Requirements
Requirements of Provision (and Location) of
Private Hydrant
• Where so required by the Fire Authority after
consultations with them.
• Fire hydrants should be positioned:
– within 100 m from an entry to any building on the
lot and not more than 100 m apart.
• In the case of a building where rising mains are
installed:
– the 100 m distance may be measured up to the
breeching inlets of the rising mains.
• Fire hydrants should be included as part of a
ring fire main system if there is a ring fire main
system.
Surface Box & Cover
Main
Gate
≤100m
≤ 100m
Distance between breeching inlet and fire hydrant
≤ 100m
Water Supply and Pumping Arrangement of
Fire Hydrants
1. Comply with the modes of supply in SS 636:2018 - CP on Water
Services (formerly CP48)
2. Only private hydrants below 125 m RL can receive direct supply
3. Pressures and flows must be adequate (38 l/s at 3.5 bar) at all
times to serve the required number of jets likely to be used.
4. Even though direct supply is possible, storage cistern of sufficient
capacity with pumping facilities may be required
• to meet SCDF's requirements on flow rates and pressure.
Water Supply and Pumping Arrangement of
Fire Hydrants
5. Independent Supply to FH
• Water supply to FH - kept entirely independent of water
supplies feeding other installations
• Include those for other fire fighting systems.
• Does not include (exceptions):
a) The Y-connection from PUB main with one branch for the FH and
the other branch fitted with a control valve, for other uses provided the flow rate for the FH or rising main is adequate.
b) Where a number of FHs are required because of the extensive
area of the premises to be covered, the mains supplying these FHs
should be in the form of a ring main to form a complete circuit of
the site
Water Supply and Pumping Arrangement of
Fire Hydrants
6.
Supply pipes feeding FHs from PUB mains shall branch off at a point
upstream of the domestic supply line.
7.
A gate valve shall be provided to cut off the supply to the domestic line
in the event of fire.
(1) Supply Pipe to FH
(2) Upstream of Domestic Supply Line
(3) Gate Valve
(4) Supply Pipe to Domestic Line
Water Supply and Pumping Arrangement of
Fire Hydrants
• Fire Hydrants Located Above 125 m RL
– Water storage tank capacity
• For residential & non-residential developments
• Table 1 for FHs located above RL 125 m within the same Plot.
Examples
A) A 3-storey residential development has 1 FH in its compound and the ground level
is 126m RL. Is there a need to have a water tank for the FH?
B) If required, what is the effective capacity of the water tank for the FH?
C) If tank is required, does the following rectangular tank with a 10m x 10m base area
meets the requirement?
3m
10 m
1.5 m
Water Supply and Pumping Arrangement of
Fire Hydrants
• Table 1 for FHs located above RL 125 m within the same Plot.
Water Level
1.02m < 1.5m
Minimum Storage Capacity
= 38 L/s x 45 x 60 s
= 102,600 L
= 102.6 m3
= 10m x 10m x 1.02m
Typical Structure and Components of Water Storage Tank
02b TYPES of RISING MAINS
and THEIR REQUIREMENTS
in BUILDINGS
Reference:
Chapter 6 – FIRE FIGHTING SYSTEMS
Section 6.2 – Rising Main & Hose Reel System
Ref: Chapter 2 > Main Risers & General Regulatory Requirements
Reasons for installing dry rising mains
• For Building height > reach of fire engines
– render external fire fighting not possible
– rising main or Dry Riser will be required
• Dry Riser System
– main pipe installed vertically through the building
– an inlet or breeching inlet provided at street level,
– fire brigade can pump water into pipe via breeching inlet
• Outlets (Landing Valves)
– provided at each level except the ground floor
– fire brigade can attach fire-fighting hoses.
– strapped & padlocked - property of SCDF
Dry Riser
Breeching
Inlet
Distance between breeching inlet and fire hydrant
Breeching Inlet
100m
Outlet Landing Valve
Source: http://www.nfec.gov.sg/firePg_HDB_guidelines.html
Dry rising mains
• For purpose groups II, III, IV, V,
VI, VII and VIII.
• On every floor, water is available
for fire-fighting via the landing
valves.
• Hoses
– connected at the landing valve,
and
– run off to the location of fire
Buildings are divided into 8 purpose groups (fire code)
Purpose Group
Description
I
Small residential
II
Other residential
III
Institutional
IV
Office
V
Shops
VI
Factories
VII
Place of Public Resorts
VIII
Storage
Fire Codes 2013
Purpose Group I
Private dwelling
house such as
bungalows, semidetached houses
and terraces
houses.
Reasons for installing wet rising mains
• Requirements for Wet Riser
– For building height > fire brigade pumping capacity
– Rising main shall be fitted
• c/w own water supply arrangement
• primed at all time
Water Supply
Arrangement
Among other things, wet riser requires water
tank (on roof or low level) and one or more
set of pumps, see next slide for example.
Example of a wet riser system with lower level water tank
Number of Rising Mains
• Requirements on the number and distribution of rising mains
are as follows:
(a) All parts of any floor (of the building) not more than 24m above
the ground level is within 38 m from a landing valve
•
the distance to be measured along a route suitable for hose lines,
including any distance up or down a stairway.
(b) One (1) rising main is provided for one or a series of floors higher
than 24 m above ground level
•
•
with each rising main serving not more than 930 m2 of any floor and
subject to all parts of the floor to be within 38 m from a landing valve.
Floor
Landing
Valve
Location of Rising Mains and Landing Valves
• The rising mains and the associated landing valves shall be positioned
in the following manner:
a. Within smoke-stop lobby
b. In the common area and within a protected shaft
c. Immediately outside the exit staircase if there is no smoke-stop lobby
d. Inside exit staircase where smoke-stop lobby and common area are not
provided
e. Rising mains shall be so located that they are protected against
mechanical and fire damage
f. No part of a rising main shall be placed in any shaft containing gas, steam
or fuel pipelines or electrical cables and wirings
Size of Rising Mains
• Minimum nominal bore of a rising main shall be:
a. 100 mm
• where the rising main does not exceed 45 m in habitable
height
• only ONE (1) landing valve is provided at each floor
b. 150 mm
• where the rising main either:
➢ Exceeds 45 m in habitable height or
➢ Is permitted to have TWO (2) landing valves on any floor.
Rising main does not exceed 45 m in habitable
height and only one (1) landing valve is
provided at each floor
< 45m
Two (2) landing valves
on any floor.
> 45m
< 45m
Breeching inlets
The requirements of the breeching inlets are
as follows:
1. Inlets with instantaneous male couplings for
connecting to the SCDF's 63.5 mm diameter
standard hose shall be fitted to each rising
main as follows:
a. A two-way breeching inlet for a 100 mm
bore rising main.
b. A four-way breeching inlet for a 150 mm
bore rising main.
Breeching Inlets Location
The breeching inlets shall be located as with the following
consideration (Some common considerations):
•
•
•
•
•
Available of fire hydrants,
The possibility of damage resulting from falling glass from
windows, and
Other possible occurrences during a fire.
On an external wall or in a boundary wall of a building and to
be within 18 m of the adjacent fire appliances access road
At street level
Max 100m and Min 6 m
≤18m
≤18m
Water supply and Pumping Arrangements
• The requirements of the water supply to the wet risers are
(some salient points):
1.
Shall comply with the modes of supply stipulated in SS 636:2018 Water Services
2.
Essential that pressures and flows be adequate at all times to serve
the required number of jets likely to be used, irrespective of the
source of water supply.
3.
The storage cistern of sufficient capacity with pumping facilities is
required to meet SCDF's requirements on flow rates and pressure.
Ref: Chapter 2 > Main Risers & General Regulatory Requirements
Flow Requirements for Wet Rising Mains
(salient points)
• The following minimum water supply flow-rate shall be maintained in
the wet rising system during operation of the system:
Water Supply For Design Of Wet Riser System
(Min duration=30 minutes)
The minimum water storage capacity shall be capable of supply water at the above said
flow rate for the periods as specified in SS 575: 2012 CP for Fire hydrant, rising mains and
hose reel systems (SS 575)
• A minimum running pressure of 3.5 bar and a maximum of 5.5 bar shall
be maintained at each landing valve when any number, up to 3, are fully
opened.
Wet Riser Tank
Exercise 2
What is the minimum effective
capacity of the wet riser tank?
03 ELECTRICAL
FIRE ALARM SYSTEM
Reference:
Chapter 6 – FIRE FIGHTING SYSTEMS
Section 6.3 – Electric Fire Alarm System
Fire Alarm System- overall schematics
44
For details of each sub-systems ( circled above) , see next slide
Fire Detection and Alarm
• Roles
– 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.
• Main Functions
1. Firstly, they provide a means to identify a developing fire through
either manual or automatic methods
2. Secondly, they alert building occupants to a fire condition and the
need to evacuate.
3. Another common function is the transmission of an alarm notification
signal to the fire department or other emergency response
organization.
• Actions
– They may also shut down electrical, air handling equipment or special
process operations, and they may be used to initiate automatic
suppression systems.
Fire Alarm Control Panels
• Function of Control Panel
– Control panel is the "brain" of the fire detection and alarm system
– It is responsible for monitoring the various alarm "input" devices such
as manual and automatic detection components
– It then activates alarm "output" devices such as horns, bells, warning
lights, emergency telephone diallers, and building controls
• Design
– Control panels may range from simple units with a single input and
output zone, to complex computer driven systems that monitor several
buildings over an entire campus.
• Types
– There are two main control panel arrangements
• conventional and
• addressable.
Conventional or "Point Wired" Fire Detection
and Alarm Systems
• Conventional
– One or more circuits are routed through the protected
space of the building.
– Along each circuit, one or more detection devices are
placed.
• Factors for Selection & Placement
– depends on need for automatic or manual initiation
– ambient temperature & environmental conditions
– anticipated type of fire
– desired speed of response
Conventional or "Point Wired" Fire Detection
and Alarm Systems
• Fire Occurrence Situation
– One or more detectors will operate.
– Action will closes the circuit, which the fire control panel recognizes as
an emergency condition.
– Panel will then activate one or more signaling circuits to sound building
alarms and summon emergency help
– Panel may also send the signal to another alarm panel so that it can be
monitored from a remote point.
• Fault Monitoring
– To help insure that the system is functioning properly, these systems
monitor the condition of each circuit by sending a small current through
the wires.
– Should a fault occur, such as due to a wiring break, this current cannot
proceed and is registered as a "trouble" condition.
– The indication is a need for service somewhere along the respective
circuit.
Electrical Fire Alarm System
Advantages and disadvantages
Advantages
Disadvantages
1. Relatively simple for
small to intermediate
size buildings.
1. For large buildings, they can be expensive to install because
2. Servicing does not
require a large amount
of specialized training.
of the extensive amounts of wire that are necessary to accurately
monitor initiating devices.
2. Inherently labour intensive and expensive to maintain.
Each detection device may require some form of operational test to
verify it is in working condition. Smoke detectors must be
periodically removed, cleaned, and recalibrated to prevent
improper operation.
There is no accurate way of determining which detectors are in
need of servicing. Consequently, each detector must be removed
and serviced, which can be a time consuming, labour intensive,
and costly endeavour.
3. Does not specifically state where the problem
If a fault occurs, the "trouble" indication only states that the circuit
has failed, but does not specifically state where the problem is
occurring. Subsequently, technicians must survey the entire circuit
to identify the problem.
Fire Indicator Board and Sub Indicator Board
Fire indicator board (fib)
Fault
Fire
Zone
location
BLK A
Sub Alarm Panel
BLK B
Sub Alarm Panel
Sub Indicator Board (SIB)
Sub Indicator Board
BLK A
Fault
Fire
Zone
Location
1st Storey
Manual Callpoint
Addressable (or Intelligent) Systems
• Addressable System versus Conventional Methods
– Addressable System is the state-of-the-art in fire detection and
alarm technology.
– Addressable System monitors and controls the capabilities of
each alarm initiating and signalling device through
microprocessors and system software.
– Major difference - involves the way in which each device is
monitored.
– In an addressable system, each initiating device (automatic
detector, manual station, sprinkler water-flow switch, etc.) is
given a specific identification or "address".
➢This address is correspondingly programmed into the control panel's
memory with information such as the type of device, its location, and
specific response details such as which alarm devices are to be activated.
Addressable (or Intelligent) Systems
• Operations
– The control panel's microprocessor sends a constant interrogation signal over
each circuit
– Each initiating device is contacted to inquire its status (normal or emergency).
– This active monitoring process occurs in rapid succession, providing system
updates every 5 to 10 seconds.
– The addressable system also monitors the condition of each circuit, identifying
any faults which may occur.
– Therefore, instead of merely showing a fault along a wire, they will indicate the
location of the problem.
– This permits faster diagnosis of the trouble, and allows a quicker repair and
return to normal.
Addressable (or Intelligent) Systems
Advantageous and disadvantageous
Advantageous
Stability
Ease of Modification
Enhanced Maintenance
If a detector recognizes a
condition which could be
indicative of a fire, the control
panel will first attempt a quick
reset.
Any connection or
removal of devices from
the addressable circuitonly require changing
the appropriate
memory section.
Able to monitor the status of each detector. As a
detector becomes dirty, the microprocessor
recognizes a decreased capability, and provides a
maintenance alert.
This feature, known as Listed Integral Sensitivity
Testing, allows facilities personnel to service only
those detectors which need attention, rather than
requiring a labour and time consuming cleaning of
all units.
Drift compensation. The software adjusts the
detector's sensitivity to compensate for minor dust
conditions. This avoids the ultra sensitive or "hot"
detector condition which often results as debris
obscures the detector's optics. When the detector
has been compensated to its limit, the control
panel alerts maintenance personnel so that
servicing can be performed.
For most spurious situations
such as insects, dust, or
breezes, the incident will often
remedy itself during this reset
procedure, thereby reducing
the probability of false alarm.
If a genuine smoke or fire
condition exists, the detector
will re-enter the alarm mode
immediately after the reset
attempt.
This memory change is
accomplished either at
the panel or on a
personal computer, with
the information
downloaded into the
panel's microprocessor.
Addressable (or Intelligent) Systems
Advantageous and disadvantageous
Disadvantageous
Own Unique Operating Characteristics
1. The main disadvantage of addressable systems is that each
system has its own unique operating characteristics.
2. Therefore, service technicians must be trained for the
respective system.
3. The training program is usually a 3-4 day course at the
respective manufacturer's facility.
4. Periodic update training may be necessary as new service
methods are developed.
Principles of fire detection
• Fires are detected by means of installing Fire Detectors or
FDs
• FDs are designed to detect the following characteristics (1
or more of 3 products of emission):
– Fire
– Heat
– Smoke or Flame
• No one type of FD is the most suitable for all applications
– Final choice will depend on individual circumstances
– Some premises may require a combination of different
types of FDs to achieve the best results.
Thermal (heat) detectors
• Key Features
– Highly reliable and have good resistance to operation
from non-hostile sources.
– Very easy and inexpensive to maintain.
– Do not function until room temperatures have reached a
substantial temperature - such point the fire is well
underway and damage is growing exponentially
– Not permitted in life safety applications.
– Not recommended if FD is required before substantial
flames occur - such as spaces where high value thermal
sensitive contents are housed.
Thermal (heat) detectors
• Thermal Detectors
– 2 Types of Thermal Detectors
• Spot Type Detector
• Fixed Temperature Line Type Detector
Spot Type Detectors
– Predetermined Temperature
• e.g. room with relatively high and rapidly fluctuating air temperature, e.g., kitchen, boiler
room.
– Rate-of-rise Detector
• identifies an abnormally fast temperature climb over a short time period.
Fixed Temperature Line Type Detector
– Two (2) cables and an insulated sheathing that is designed to breakdown when
exposed to heat.
Smoke detectors
• Identify a fire while in its smouldering or early flame
stages.
• There are 2 main types of Smoke Detectors:
– ionization
– photoelectric
 Ionization
– Sensitive to invisible particles released in initial stage of fire
 Photoelectric
– bigger combustion particles released in later stage of fire
Flame detectors
• The properly selected and installed automatic detector
can be a highly reliable fire sensor.
• Line of sight devices that operate on either an infrared,
ultraviolet or combination principle
• Advantageous
– extremely reliable in a hostile environment
– used in high value energy and transportation applications where
other detectors would be subject to spurious/false activation.
• Disadvantageous
– expensive and labour intensive to maintain
– must be looking directly at the fire source, cannot identify
migrating fire signatures
Alarm output devices
• Upon Receiving An Alarm Notification
– fire alarm control panel must now tell someone that an
emergency is underway.
• Primary Alarm Output Devices
– this is the primary function of the alarm output aspect of a
system.
• Occupant Signalling Components
– include various audible and visual alerting components, and are
the primary alarm output devices.
Alarm output devices
Audio
Alerts
Visual
Alerts
Telephone or
Radio Signal
Other
output
1) Bells
2) Horns - for areas where
a loud signal is needed
such as library stacks,
and architecturally
sensitive buildings
where devices need
partial concealment.
3) Chimes - where a soft
alarm tone is preferred,
such as health care
facilities and theatres.
4) Speakers - sound a
reproducible signal such
as a recorded voice
message, often ideally
suited for large, multistory or other similar
buildings where phased
evacuation is preferred.
1) Strobe and
flashing light
devices
1) An automatic
telephone or
radio signal communicated
to a constantly
staffed
monitoring
centre.
Include shutting down
electrical equipment .
Eg computers, shutting off
AHU fans to prevent smoke
migration, and shutting
down operations such as
chemical movement through
piping in the alarmed area.
May activate fans to extract
smoke, which is a common
function in large atria spaces.
Can also activate discharge
of gaseous fire extinguishing
systems, or pre-action
sprinkler systems.
04 AUTOMATIC FIRE
SPRINKLER SYSTEM
Reference:
Chapter 6 – FIRE FIGHTING SYSTEMS
Section 6.4 – Sprinkler Installation
Automatic Fire Extinguishing Systems
- Automatic sprinkler System
- Types
- Components
- Sprinkler system design
- Others:
- Water mist system;
- Foam system;
- Gas suppression system
73
AUTOMATIC SPRINKLER SYSTEM
 Effective for life safety as it gives warning of the
existence of fire, at the same time fight the fire
74
Methods of extinguishing fire:
Cooling
Starvation
Smothering
Inhibiting
75
Automatic Sprinkler System
• Automatically
–distributes water upon a fire
–transmits signal to the fire station through
the alarm monitoring station
• Holds the fire /cools the environment to
reduce fire spread before arrival of the
Fire Brigade
• Reduce smoke intensity and making the
smoke less harmful by cooling the
smoke/fire zone
76
Sprinkler System - Statutory Requirements
• Sprinkler system shall be installed in accordance to
- Fire Code 2013
- Singapore Standard CP52 : 2004 Code of
Practice for Automatic Fire Sprinkler System
- On operation of sprinkler head, fire signal shall be
AUTOMATICALLY transmitted to the fire station
through an approved alarm monitoring station
77
Sprinkler System - Provisions
• Required when compartment requirements of Fire
code cannot be complied with
• All buildings other than purpose groups I & II with
habitable height > 24m
• For mixed occupancy building (residential & non
residential) floors that are >24m, every floor of the
non-residential portion shall be sprinklered
➢ Group I: Small residential
➢ Group II: other residential
78
Fire Code 2013
79
Sprinkler System - Provisions
• All basement floors except Groups I & II
(residential) shall be sprinklered
• Basement car parks for Group II buildings shall be
sprinklered
–Exception: When there is only 1 basement and
adequate openings are provided for cross
ventilation
80
Sprinkler System - Provisions
EXCEPTIONS
• For special rooms, sprinklers can be exempted if the
rooms are properly fire compartmented:
– HT/LT switch rooms
– Transformer Rooms
– Electric Lift Motor room
– Electrical room
– Emergency lighting battery room
– MDF and PABX room
81
Sprinkler System – Main Components
• Breeching inlet
• Water storage tank
• Sprinkler pumps
• Sprinkler control valves
• Sprinkler heads
• Sprinkler pipe network,
• Fire alarm system
Sprinkler System - Types
• Wet pipe system
• Dry pipe system
• Pre-action sprinkler system
• Deluge System
83
Sprinkler System – Wet Pipe
• Simplest and most common type of installation
• System is permanently charged with water under
pressure up to sprinkler heads
• Installed where the potential for
freezing does not exist
84
Sprinkler System – Wet Pipe
OPERATIONS
• When the heat of the fire rises to the sprinkler head operating
temperature, the sprinkler head “bursts” and releases water
• A flow switch activated by the water flow movement activates
the fire alarm system
• As water pressure
in the pipe drops,
the pressure sensor
activates the
sprinkler pump
into operation to
provide the
required water
supply
Fire
Panel
Sprinkler System – Wet Pipe
FS
FS
FS
Schematic diagram of
A Wet-pipe Sprinkler
System
sprinkler heads
FS
FS
A flow switch (FS)
activated by the water
flow movement
activates the fire alarm
system
FS
WATER SUPPLY
Check valve
CONTROL
VALVES
Gate valve
SPRINKLER TANK
DUTY
PUMP
STANDBY
PUMP
1ST STOREY
Sprinkler System – Wet Pipe
Schematic diagram of
a Wet-pipe Sprinkler
System
Sprinkler System – Wet Pipe
Control Valves
89
Sprinkler System – WET PIPE
Ancillary Equipment
Installation control valves and
ancillary equipment:
A main stop valve
- An alarm valve
-
-
fitted on main supply line
When water flows, it cause the alarm gong to sound
A water motor alarm and gong
- Plates with essential information on the
installation
- Alarm equipment for automatic transmission to
fire service (flow switch)
-
90
Sprinkler System – DRY PIPE
• Above the control valve, system is charged with compressed
air/ nitrogen instead of water
• Dry pipe valve held closed by air pressure
• Upon activation of sprinkler head, air is released, and water
flows into the pipework
• For areas subject to freezing
temperatures
Compressed air
Dry pipe valve
91
Sprinkler System – PRE-ACTION
• For areas where accidental discharge of water is unacceptable
• Pipes filled with low pressure air
• Heat/ smoke detector send signal to valve to release water to pipework
and sound alarm
• When sprinkler burst, water is discharged
• Prevent unwanted water flow
when a pipe or sprinkler
is accidentally broken
• E.g. computer rooms,
Low pressure air
detector
libraries
92
92
Sprinkler System – DELUGE
• Pipes are usually empty, sprinklers are open
• Detectors activate control valve to allow water to flow
• Water is discharged simultaneously through all the open sprinklers
in the area
• Thus providing fast and total wetting of protected areas
Open
sprinkler
• For areas that require total water coverage
(extra high hazard area such as
aircraft hangars, power generating
detector
stations, and petrochemical
facilities)
Breeching
Inlet
Sprinkler
Pump
93
93
Thank
You
end