Fire Protection Overview2008

Overview of Fire Protection System

in Buildings

Conducted by Er. Koh Kin Teng, 13 Oct 2008

Fire Protection System in Buildings

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.

Fire has a triangle of needs: fuel, high temperature and oxygen. Active Fire Protection System serves to deprive fire of its needs.


Buildings commonly contain 3 basic sources of ignition: chemical, electrical and mechanical

Objectives of Fire Protection System– Protection of Life– Protection of Property– Continuity of Operation


Fire Protection System is divided into:

– Passive Fire Protection Provision: Examples are fire compartments, fire resistance, fire stops,fire collars

– Active Fire Protection Provision: Examples are automatic sprinklers, wet & dry rising mains, detectors, hydrants, extinguishers, smoke controls, etc.


Acts, Regulations & Codes in Singapore– Fire Safety Act;– Fire Safety Regulations;– Code of Practice For Fire Precautions in Buildings– Code of Practice for Automatic Fire Sprinkler System (CP 52)– Code of Practice for Fire Hydrant Systems and Hose reels (CP 29)– Code of Practice for the Installation and servicing of Electrical Fire Alarm Systems

(CP 10)– Code of Practice of Emergency Voice Communication System in Buildings (CP 25)– Code of Practice For the Storage of Flammable Liquids (SS 532)– Code of Practice For Use and Maintenance of Portable Fire Extinguishers (CP55)

Automatic Fire Sprinkler System

Why Sprinklers?Water cools, smothers, emulsifies and dilutes. It removes 2256 kJ/kg of heat as it vaporizes. It expands 1700 times and helps push away the oxygen needed by the fire.

Why not Sprinklers?Water damages content of buildings, conducts electricity as a stream and it is heavier than oil


SS CP52 was evolved from AS 2118, FOC and NFPA.Some old buildings were designed using AS 2118 or FOC. Hence care must be taken in dealing with A&A works of these buildings.Use of NFPA in industrial projects needs waiver from FSSD.For special premises and system, FSSD accepts NFPA. E.g. Wafer Clean Room, Aircraft Hangar, Hydrogen storage system and other industrial gases system.


Areas to be Protected:Buildings which is required to be sprinkler protected shall be sprinkled throughout.Areas exempted:– protected stairs with cut-off sprinklers at door openings; – 2-hr fire-rated rooms containing only electrical equipment; – non-industrial canopies external corridors and linkways (with

condition); – roof overhang (with conditions); – computer rooms (with conditions);– indoor pools.– Atrium space more than 12m height (with conditions)


Classification of Occupancies– Light hazard: sauna, boarding houses, churches,

hospitals, libraries, clinic, museums, prisons, schools.– Ordinary Hazard 1: Offices, Hotels, Restaurants, Cafes,

Clubs– Ordinary Hazard 2: Car parks, laundries, breweries,

bakery and biscuit manufacturers, Wafer Fab, etc.– Ordinary Hazard 3: Retail shops, department store,

cinemas, electronic manufacturing and assembly (predominantly metal), theatre and music halls, etc.


Classification of Occupancies– Ordinary Hazard Group 3 Special: Exhibitions, Film

and television studios– High Hazard (process risk): Aircraft hangars, foam

plastic/rubber and their goods manufacturers– High Hazard (high piled storage risk): divided into

four categories based on type of storage, wrappings and storage method and heights


Components of Automatic Fire Sprinkler System:

Sprinkler TankSprinkler Pump SetSprinkler Control Valve

Breeching Inlet

Sprinkler Flow Switch

Sprinkler Heads


R O O F T A N K

( C P 5 2 )S P R I N K L E R S Y S T E M

M

P U M P F E E D 1 9 T H T O R O O FO F F I C E( O H I )

B U L K W A T E R M E T E R

4 W A Y B R E E C H I N G I N L E T

G R A V I T Y F E E D 7 T H T O 1 8 T H S T YO F F I C E( O H I )

B A S E M E N T T A N K

P U M P F E E D B A S E M E N T T O 6 T H S T Y C A R P A R K / P L A N T R O O M / C A F E ( O H I I )

Watch out for the maximum allowable stage height above the lowest sprinklers – 75 metres

Automatic Fire Sprinkler SystemWater Supply– Elevated gravity tank– Pump supply from a pump suction tank– Booster pump supply drawing from an elevated tank

Pump Suction Tanks– Non-combustible, 2 compartments. FRP not permitted.– Shall be capable of completely refilling within 6hr for

capacity <500m3 and 24hr for capacity >500m3

– Negative suction pumps are not allowed.


Pump Suction Tanks shall have minimum effective capacityas stated in Table 16 & 24 for OH & HH.With auto inflow, tank storage capacity can be further reduced (Clause 11.2.2.2). CHECK with Project Director.In 2001, FSSD has further reduced the requirement of minimum capacity for non-industrial buildings with OH Group <60m. Full hydraulic calculations must be adopted to justify tank capacity. We do not recommend this.In 2003, FSSD allows combined sprinkler & wet riser tank. CHECK with Project Director before committing.


Sprinkler Pumps– Shall be listed by PSB, FM or UL or LPC.– Two pumps, one duty and one standby.– Either both pumps are connected to emergency power supply

or one is engine-driven.– Fuel tank & pipe: full load operation for 4 hrs; separate &

independent for each engine.

Automatic Fire Sprinkler SystemSprinkler Pumps– Must be housed in a sprinkler protected room.– Must meet the water and pressure requirement

stipulated in Table 14, 17 or 23 of CP52:2004– Pumps shall be installed under positive head

condition. Pumps installed under suction head is NOT allowed.

– Jockey pump (small flow and high head) is required for pressure maintenance.

– Starts automatically when system pressure drop to predetermined level and stops only manually.

Sprinkler PipesBlack steel pipe to BS 1387Class B or C

Control ValvesAlso known as Alarm ValvesFor water proving purposeShall be located near FCC, in FLL or protected area accessible from common areaAlarm and valve status connects to BMS or guard houseArea controlled by one control valve:

9,000 m2 for LH/OH8,000 m2 for HH4,000 m2 for HH in-rack sprinklers



Types of Sprinkler heads– Temperature ratings: 68°C, 79°C, 93°C, 141°C– K factors: 2.8, 4.2, 5.6, 8.0, 11.2, 14.0 liters/(min.kPa)– Mounting: pendent, upright, sidewall, recessed

pendent (Royal Flush)– Type of response: standard [RTI ≤50(m/s)½ ] and

quick response [RTI ≥80(m/s)½]– Type of coverage: Standard and extended coverage


Sprinkler spacing (see Fig. 14 & 15 in CP52:2004)Sprinklers are required in – lift pits and shafts; – escalator boot and motor spaces; – spaces under escalators and unenclosed staircases, – under rectangular duct>800mm width, – roof overhangs >1.5m, ext. corridor>4m, ext. linkway >3m

Sprinklers may be required for concealed ceiling and floor spaces exceeding 400mm in depth (see Clause 6.6.2 in CP52:2004)


Pre-action Sprinkler SystemStandard sprinkler system + detector system installed within the same areas.fire→ detectors operate→ opens pre-action valve→water charges sprinkler pipes→ first sprinkler activates when temperature is reached.

Commonly used in data centers.Pre-action valve- housed in a fire compartment.Pre-action panel-outside protected area; reflects status of flow switch, detectors, solenoid valve, air pressure, etc. ; linked to the SFIB.


Dry Pipe SystemSprinkler system - pipework is permanently charged with air under pressure above the dry-pipe alarm valve and with water under pressure below the valve. It is only allowed in rooms close to freezing or boiling.When sprinkler heads burst, air pressure in pipeline drops and valve opens, allowing water to charge in and be discharged from the sprinkler heads.

Deluge SystemSeries of open sprinklers (nozzles) controlled by a quick opening valve (deluge valve) which is operated by a system of detectors installed within the same area.


Sprinkler pipe sizing– Partly pre-calculated pipe sizing

Table 18 for OH groupTable 25 of CP52:2004 for EH groupThe pressure loss from each Design Point to the control valve shall not exceed 150kPa with a flow of 1800 L/min (see sample calculations).

– Full hydraulic calculations shall be discussed in separate session (see sample calculations with FHC software).


Caution:– Minimum range pipe size is 25mm.– Only used in areas where future alteration works are

known to be minimal, such as the upright sprinklers in the concealed ceiling space of office.

– It is NOT recommended to be used in commercial area, whether pendent or upright.

– Pipe directly feeding a dropper more than 300mm length is considered a distribution pipe (see Fig. 4 of CP52:2004). In this case, 25mm is NOT allowed.


Common Mistakes in Submission Plans– Submission areas are not clearly edged out– Affected Control Valves not highlighted/indicated– Table indicating Control Valve No, Hazard Group, Area

Served, Density of Discharge, Pressure & Flow requirement, No. of Sprinklers not provided

– Calculations not submitted for partly pre-calculated system and gravity fed system (see sample calculation)

– Design Points not indicated– Undersized pipe (partly pre-calculated system)

Dry & Wet Rising Main System

Dry Rising Mainfor 10m<building with any habitable floor<60mWet Rising Mainfor building with any habitable floor>60mCode: CP29:1998Architect is required to indicate No. of rising mains, locations of landing valves and breeching inlets in their fire plan submission.


Dry Riser Landing Valve is painted in yellow.Wet Riser Landing Valve is painted in red.The valves shall be strap-locked in the closed position.


Wet Riser Zone Height Limitation– Maximum zone height shall not exceed 120m.– Pressure regulating device regulate to 3.5-5.5 bar.

Number of Rising Main– All parts of any floor is within 38m from a landing

valve, the distance to be measured along a route suitable for hose lines.

– Each rising main shall serve not more than 930m2 of any floor and subject to all parts of the floor to be within 38m from a landing valve.


Locations of rising mains and landing valves in the following order of priority:– Within smoke stop lobby;– In the common area and within a protected shaft,

immediately outside the exit staircase if there is no smoke stop lobby;

– Inside exit staircase where smoke-stop lobby and common area are not provided.

Protected against mechanical and fire damage;Shall not be placed in shaft containing gas, steam, fuel pipes or electrical cables.


Size of rising main:-100mm when habitable height<45m and one landing valve per floor-150mm when either habitable height>45m or >1 landing valve per floorBreeching Inlets– Within 18m of adjacent fire engine

access road– 2-way for 100mm riser– 4-way for 150mm riser


Landing Valve– Installed at 760mm~1000mm above ground– Recessed clearance as per Fig. 3 in CP29:1998

Water supply for wet rising main– Reliable water supply source– Pump suction tank shall be non-combustible and

twin-compartmented. FRP tank not permitted.– Transfer tank effective capacity shall be at least

11.5m3 per rising main.


Water storage for wet rising mains– Generally roof tank capable of 30 min water supply rate.– Generally tank receiving from PUB shall be sized to 45

min water supply rate.Flow Requirement for wet rising mainsWhen 3 landing valves are in fully opened position:– 27L/s for residential building;– 38L/s for non-residential or mixed occupancy– Running pressure within 3.5bar to 5.5bar.


For common water supply to more than one rising main (max. total 9 rising mains)– For residential building:

27 + 13.5 (n-1) L/s up to max. 67.5L/s– For non-residential or mixed occupancy:

38 + 19 (n-1) L/s up to max. 95L/s

Where n is the no. of rising main.


Wet Riser Pump– Must be listed by PSB and FM, UL or LPC;– Arrangement is the same as sprinkler pumps, i.e one

duty and one standby.– Either both are connected to emergency power supply

or one of them is engine-driven type.– Starts automatically when pressure in the main drops by

more than 5% of the churning pressure and stop only manually.

– Must be housed in a fire-resistant room housing fire pumps only.


Other things to note:– Galvanized steel pipe is commonly used.– Rising mains must be electrically earthed.– Automatic air release valve must be installed at top of

the rising main.– No-drain wet riser landing valves– Landing valves are required at roof.– Testing facilities to be provided.– Standby Fire Hose next to landing valve (except

residential).

Fire Hydrants

Fire hydrants location and quantity to be determined by Architect.Pillar type with two 63.5mm outlets or three outlets (1×114mm & 2×63.5mm).SS CP29:1998 governs the design & installation

Fire Hydrants

Private fire hydrants shall be painted with a 100mm yellow band on the stem.Water supply– Hydrants installed below 125mRL can receive direct

supply from PUB mains. Otherwise, storage tank and pumping facilities shall be provided.

– Refer to Table 4.4.2 of Code of Practice for Fire Precautions for Buildings 2007 for storage tank capacity for hydrants.

Fire Hydrants

Pressure and flow requirement for private hydrants installed below 125m RL:– Running pressure at hydraulically most unfavourable

private hydrant 0.9 × (running pressure of nearest public hydrant – ∆P across bulk meter)

– Flow at hydraulically most unfavourable private hydrant 0.9 × water flow of nearest public hydrant or total flow demand as required in Table 4.4.2 of Code

of practice for Fire Precautions in Buildings 2007

Fire Hydrants

Fire Hydrant Mains– Ductile iron cement-lined pipe– Valve pit and cover on road must be able to

withstand vehicular load for that road– Hydrant mains trespassing a building shall have its

full length within the building protected with fire-resistance construction of same fire resistance as the element of structure.

Fire Hose Reel

Hose reel locations and quantity to be determined by Architect.Comes with or without cabinet, but our specifications call for it.Fixed type and swing type.Automatic type: valve automatically turn on after one revolution of reel.

Fire Hose Reel

All part of each floor shall be within 6m of the nozzle attached to not more than 30m of hose.Preferable sited outside protected corridors, lobbies or staircases on exit routes.Do not form obstruction on escape route.Recessed doors can open 180° and should not be fitted with locks. If locked, they shall be tempered glass panel to facilitate unlocking from the inside, without using a key.

Fire Hose Reel

Water supply– Hydraulically most unfavourable hose reel shall

provide a jet of 6m in length at 0.4 L/s. With 6mm nozzle, this means a running pressure of 2 bar is required at entry to each reel.

– Pipe commonly used is galvanized steel.– Hose reel pumps shall be one duty & one standby

and connected to emergency power supply.– Hose reel pumps starts automatically with a drop in

pressure and stopped manually.

Fire Hose Reel

Water storage:– Minimum capacity 1100 L.– Shared with domestic tank or sprinkler tank shall be

such a manner that the hose reel suction pipe is located below the domestic water suction pipe. In this way, requisite reserve of water for hose reels is always preserved. Provisions to be allowed to prevent contamination.

Automatic Fire Alarm System

System consists of:– Main Fire Alarm Panel– Sub Fire Alarm Panel– Mimic panels– Detectors, either heat, smoke

or flame;– Manual call points (break

glass)– Alarm bells– Optional items such as

repeater panels, computer desktop & printers


SS CP 10: 2005 governs the installation and servicing of electrical fire alarm systemsManual or Automatic Fire Alarm? Refer to Table 6.3A of Code of Practice for Fire Precautions in Building 2007. It depends on type of building, floor area & No. of storey.For commercial-cum-residential occupancy, the residential floors shall be provided with manual alarm system at common area. If height<24m, only alarm bells are extended to residential floor.For residential apartments above car park, alarm bells of the fire alarm system shall be extended to residential floors


Architect to advise manual or automatic fire alarm system. (They have to state in their BP)Only automatic fire alarm system requires submission to FSSD and connection to DECAM.Area exempted from detector protection:– Raised floor < 150mm depth;– Sanitary spaces < 3.5m2;– Open-side linkway;


Type of Automatic Fire Alarm System– Conventional System

• A hard-wiring system in which only signals from each alarm zone are identified at the control panel.

– Addressable System• A microprocessor-based system in which signals from each

detector, call point and/or activating devices are individually identified at the control panel.

• Each device is coded with an unique address and these addresses are programmed into the memory of MFAP.

• Scanning, interrogation, decision and other signal processing• Loop configuration, thereby flexible for additions and

alterations.


Main Fire Alarm Panel– controls the receipt and transmission of signals within the

fire alarm system– initiates other actions, e.g. lift homing.– provides alarm and fault signal in visual and audio form.

Sub Fire Alarm Panel– is located remotely from MFAP– have either alarm zone facilities or indicators to identify

alarm location and transmit such alarm to MFAP.


Main Fire Alarm Panel shall consists of:– Indication facilities for alarm, fault, system

energization and isolation .– Monitoring facilities for power supply;– Warning buzzer for fault and alarm;– Signal transmitter to DECAM– Fire alarm sounder acknowledge/silencing switch

(only allowed to silenced after 3 minutes for buildings without EVC)

– Output drivers for interfacing with lifts, life saving fans, fire shutters, secured doors, etc.


Sub Fire Alarm Panel– In conventional system, alarm and fault indicators,

and isolation facility shall be provided.– In addressable system, only alarm indicators.

Mimic Panel– Shows alarm zone indication in a diagrammatic form.

It must be installed in accordance with its floor and building orientation.

Repeater Panel– Duplicate panel installed in locations other than FCC

Automatic Fire Alarm SystemSmoke Detectors– Optical Type (or Photoelectric)

• Infra-red light beam and a photosensor inside the optical chamber. Normally very little light from the beam reaches the sensor, but smoke causes the beam to scatter & reach sensor, triggering the alarm

• Application – detecting visible smoke from smouldering fires, e.g. plastic foam, cables

– Ionization Type• Uses radioactive source to ionize the air. Smoke in

ionization chamber changes balance voltage, which is then compared against a level and raise alarm.

• Application – fast burning, high energy fires which generate very small sized smoke aerosol products.


Heat Detectors– Fixed Temperature Type

• Operating when temperature at the detector reaches a preset level of temperature

• Suited for areas where temperature can fluctuate for natural reasons

– Rate of Rise Type• Operating when temperature rises quickly• Ideal for areas where temperature is normally fairly stable.• A fixed temperature “backstop” circuit at preset temperature for greater safety.

– Combined Fixed Temperature & Rate of Rise


Flame Detector– Designed to respond to fires involving

petrol or gases like methane.Duct Detector– For installation on air stream at return air

duct for AHU exceeding 15,000 cmH.High Performance Optical Detector– Combines optical & heat detector

technology– From slow smouldering fire to open fire

flames


Detector spacingBetween detectors Detector to wall

Smoke Detector 10.2m 5.1m

Heat Detector 7.2m(other areas) 3.6m(below 3.5m height) 10.2m(corridor) 5.1m

Flame Detector requires unobstructed line of sight to “see”


Manual Call Point– Break-glass type– MUST be in red colour.– Locations to be advised by Architect– Should be fixed at 1.4m above floor– “In case of fire, please call 995” for manual

fire alarm system

Alarm Bell– Our specification calls for 85dBA @ 3m

Very Intelligent Early Warning System

Very Intelligent Early Warning (VIEW)– In critical areas, very early warning of a potential fire in advance of

damage to equipment is vital, e.g data centre.– It can be combined with clean agent fire extinguishing system such

as FM200™, INERGEN, etc to complement fire extinguishing.– Allows area personnel to investigate and handle without system

discharge.– VESDA (Very Early Smoke Detection Alarm) System is the most

widely used air sampling system.


Air samples are drawn into the sampling pipe and carried through to the Detector by the aspirator.

Sampling point

Detail of Sampling

point

Sampling pipe

Air samples

Overview of VESDA


Clean Agent Fire Extinguishing System

Cannot substitute sprinklers unless otherwise permitted– Inert Gas Agent reduces oxygen level

• INERGEN® (52% nitrogen, 40% argon and 8% carbon dioxide)

• ARGONITE (50% argon, 50% nitrogen)• Argon• Carbon dioxide

– Halocarbon Agents extinguishes by chemical reaction

• Zero ODP, low GWP and toxicity• FM200® (HFC-227ea)• FE-13, FE-25 and NAFG S111

Mostly used in Data Centres and Server RoomsSystem must comply with NFPA 2001;Must meet minimum design concentration for the specific fire class:– Class A: Ordinary combustible material such as wood, cloth, paper, rubber and

many plastics;– Class B: Flammable liquids, oils, greases, tars, oil-based paints, lacquers, and

flammable gases– Class C: Energized electrical equipment where electrical non-conductivity of

extinguishing media is of importanceTypically for Data Centre, minimum design concentration (by volume) shall be 7% for FM-200 and 40% for INERGENINERGEN is not effective on Class D – Combustible metals such as sodium, potassium, magnesium, titanium and zirconium; or Cellulose Nitrate which contains its own oxygen supply; or metal hydrides.



--Unoccupied Areas. No exposure

C>62%

Means provided to limit exposure and personnel can escape within 30 secs

30 secondsNormally Unoccupied, possible exposure

52%≤C<62%

Means provided to limit exposure3 minutesNormally Occupied43%≤C<52%

Means provided to limit exposure5 minutesNormally OccupiedC<43%

INERGEN® and other Inert Gas Agents

Means provided to limit exposure and personnel can escape within 30 secs

0.49 to 1.13 minutes

Normally Unoccupied, possible exposure

C>LOAEL

Means provided to limit exposure5 minutesNormally OccupiedNOAEL<C≤LOAEL

--Normally OccupiedC ≤ NOAEL

FM-200® only (NOAEL is 9% and LOAEL is 10.5%)

RemarksMax. Exposure

Time

OccupancyAcceptable Concentration, C

When Clean Agents are discharged into a room, air and small amount of clean agent is displaced out of the room.


510 ft3 INERGEN

1,000 ft3 Room

400 ft3 INERGEN

600 ft3 Air

110 ft3 INERGEN

400 ft3 Air

INERGEN going into the room = Flooding Factor = 51%

INERGEN remaining in room = Design Concentration = 40%

Flooding Factor – Design Concentration = INERGEN displaced

Fire Extinguishers

Fire Extinguishers– Dry Chemical (ABC Dry Powder) Type

• Suitable for Class A, B and C fire– Carbon Dioxide Type

• Suitable for Class B and C fire

Emergency Voice Communication System

Emergency Voice Communication System– CP25 governs the design, installation, testing & commissioning

of EVC system in buildings.– Architect to advise as to whether EVC (one-way or two-way) are

required in the proposed development.– For buildings (Group 3,4,5,7) 24m~60m habitable height, two-

way EVC is required in FCC & every fire fighting lobby– For buildings (Group 3,4,5,7)) >60m, one-way EVC shall be

provided in additional to two-way EVC provided in FCC, fire fighting lobbies, fire-related plant rooms, AHUs, lift motor rooms

– Fire alarm to override normal PA system during fire.

Special Fire Protection System

Aircraft Hangars– NFPA 409:2001– Foam Water System– Grouping of Aircraft Hangars– 3 Options

• Overhead Foam-Water Deluge system (primary) and supplementary system to protect shadow areas under wings (secondary);

• Overhead closed head wet-pipe sprinklers (quick response) and Low-level Low Expansion Foam System

• Overhead closed head wet-pipe sprinklers (quick response) and Low-level High Expansion Foam System

Grate Nozzles

Oscillating Monitors

Special Fire Protection System


Documents

Fire Protection Overview2008