This document provides an overview of fire protection systems for buildings. It discusses the science of fire and the four main classes of fire. It then describes various active fire protection methods like fire detection, sprinkler systems, and firefighting water storage. It provides details on internal firefighting systems for residences and industries. Common fire suppression systems for different hazards are also outlined, including sprinklers, foam, dry chemical powder, and carbon dioxide systems.
2. INTRODUCTION
FIRE SAFETY IS A SUBJECT CONNECTED NOT ONLY WITH HUMAN AND
PROPERTY SAFETY BUT IS RELATED WITH DESIGN OF BUILDINGS AND THEIR
SERVICES. FIRE ALTHOUGH A GOOD FRIEND OF HUMANITY, WHEN IT SPREADS
UN-CONTROLLED, IN BUILDINGS CAN BE VICIOUS ENEMY RESULTING IN HEAVY
LOSS OF PROPERTY AND LIVES.
THEREFORE FIRE PROTECTION MEASURES, BOTH IN RESIDENTIAL BUILDINGS
AND IN COMMERCIAL/ INDUSTRIAL COMPLEXES, HAVE ASSUMED A GREAT
ROLE IN RECENT YEARS IN OUR COUNTRY.
FIRE SCIENCE
FIRE IS THE PROCESS OF BURNING. IT IS INFACT A CHEMICAL REACTION
INITIATED BY PRESENCE OF HEAT ENERGY IN WHICH A SUBSTANCE COMBINES
WITH OXYGEN IN THE AIR AND THE PROCESS IS ACCOMPANIED BY EMISSION
OF ENERGY IN THE FORM OF HEAT, LIGHT AND SOUND. THEREFORE, THREE
ELEMENTS ARE ESSENTIAL FOR COMBUSTION I.E.
ACOMBUSTIBLE MATTER I.E FUEL
OXYGEN
SOURCE OF HEAT, SPARK FLAME ETC.
THERE ARE 4 CLASSES OF FIRE
Class A
ORDINARY COMBUSTIBLES OR FIBROUS MATERIAL, SUCH AS
WOOD, PAPER, CLOTH, RUBBER, AND SOME PLASTICS.
Class B
FLAMMABLE OR COMBUSTIBLE LIQUIDS SUCH AS GASOLINE,
KEROSENE, PAINT, PAINT THINNERS AND PROPANE
Class C
ENERGIZED ELECTRICAL EQUIPMENT, SUCH AS APPLIANCES,
SWITCHES, PANEL BOXES AND POWER TOOLS.
Class D
CERTAIN COMBUSTIBLE METALS, SUCH AS MAGNESIUM,
TITANIUM, POTASSIUM, AND SODIUM.
3. FIRE PROTECTION
A METHOD OF FIRE PROTECTION INVOLVES
THE CONVEYANCE OF WATER I PIPES TO
EXTINGUISH FIRE WITHIN A BUILDING FALLS
INTO THE FIELD OF PLUMBING. WATER MAY
BE SUPPLIED THROUGH RISER PIPES OR
STANDPIPES. A RISER OR STANDPIPES WITH
HOSE CONNECTIONS IN A TALL BUILDINGS
MAY BE FED FROM STORAGE TANK, FROM
PUMP OR FROM A MOBILE PUMPING
ENGINE IN THE STREET CONNECTED TO A
BREACHING OR ‘SIAMESE POST’
AUTOMATIC SPRINKLER ARE THE DEVICES
THAT DISCHARGE WATER AUTOMATICALLY
WHEN THE TEMPERATURE OF AIR
SURROUNDING SPRINKLER REACHES A
PREDETERMINED LEVEL.
FIRE PROTECTION IN LAND-BASED BUILDINGS, OFFSHORE CONSTRUCTION
OR ONBOARD SHIPS IS TYPICALLY ACHIEVED VIA ALL OF THE FOLLOWING:
PASSIVE FIRE PROTECTION - THE INSTALLATION OF FIREWALLS AND FIRE
RATED FLOOR ASSEMBLIES TO FORM FIRE COMPARTMENTS INTENDED TO
LIMIT THE SPREAD OF FIRE, HIGH TEMPERATURES, AND SMOKE.
ACTIVE FIRE PROTECTION - MANUAL AND AUTOMATIC DETECTION AND
SUPPRESSION OF FIRES, SUCH AS FIRE SPRINKLER SYSTEMS AND (FIRE
ALARM) SYSTEMS.
COMPONENTS
4. ACTIVE FIRE PROTECTION
ACTIVE FIRE PROTECTION (AFP) = IS AN INTEGRAL PART OF FIRE
PROTECTION. AFP IS CHARACTERISED BY ITEMS AND/OR SYSTEMS, WHICH
REQUIRE A CERTAIN AMOUNT OF MOTION AND RESPONSE IN ORDER TO
WORK, CONTRARY TO PASSIVE FIRE PROTECTION.
CATEGORIES OF ACTIVE FIRE PROTECTION
FIRE DETECTION
FIRE IS DETECTED EITHER BY LOCATING THE SMOKE, FLAME OR HEAT, AND
AN ALARM IS SOUNDED TO ENABLE EMERGENCY EVACUATION AS WELL AS TO
DISPATCH THE LOCAL FIRE DEPARTMENT.
HYPOXIC AIR FIRE PREVENTION
FIRE CAN BE PREVENTED BY HYPOXIC AIR. HYPOXIC AIR FIRE PREVENTION
SYSTEMS, ALSO KNOWN AS OXYGEN REDUCTION SYSTEMS ARE NEW
AUTOMATIC FIRE PREVENTION SYSTEMS THAT REDUCE PERMANENTLY THE
OXYGEN CONCENTRATION INSIDE THE PROTECTED VOLUMES SO THAT
IGNITION OR FIRE SPREADING CANNOT OCCUR.
REQUIREMENT OF WATER
THE QUANTITY OF WATER REQUIRED FOR FIRE EXTINCTION DEPENDS UPON
THE MAGNITUDE OF FIRE AND DURATION TAKEN TO EXTINGUISH IT. THE USE
OF NON-POTABLE WATER SHOULD BE AVOIDED FOR THE FEAR OF CROSS
CONNECTION AND SUBSEQUENT HEALTH HAZARDS.
THE SIZE OF MAIN RING, DRY RISER AND WET RISER, FOR FIRE FIGHTING
WITHIN A BUILDING, IS DESIGNED KEEPING IN MIND THAT A DISTANT
HYDRANT WILL DISCHARGE ABOUT 1000 LITRES PER MINUTES AT 3.5
KG/SQ.CM PRESSURE. AND AT ANY GIVEN TIME AT LEAST TWO HYDRANTS ARE
IN OPERATION.
5. STORAGE OF WATER
A SUFFICIENT QUALITY OF WATER FOR THE PURPOSE OF FIRE FIGHTING OF
THE BUILDING MUST BE MADE AVAILABLE IN AN UNDERGROUND TANK
WITHIN THE PREMISES. TANK CAPACITY MAY BE TAKEN AS 30 MIN WATER
SUPPLY AT 1000 LITRES PER MINUTES THE WATER TANK AND COVER SHOULD
BE DESIGNED TO TAKE LOAD OF 18 TONNES VEHICULAR LOAD IF FLUSH
BELOW GROUND LEVEL.
THE FIRE FIGHTING STORAGE AND PUMPS REQUIREMENTS AS PER
DEVELOPMENT CONTROL REGULATION OF THE MUNICIPAL CORPORATION OF
DELHI
SYSTEMS OF FIRE FIGHTING
IT MAY BE BROADLY CLASSIFIED AS EXTERNAL (CITY) AND INTERNAL
( BUILDING) FIRE FIGHTING SYSTEM
EXTERNAL FIRE FIGHTING SYSTEM
FIRE HYDRANT ARE GENERALLY LOCATED AT A DISTANCE APART OF ABOUT
90 M TO 120 M IN INHABITANT AREA AND ABOUT 300 M IN AN OPEN AREA.
ONE FIRE HYDRANT FOR EVERY 4000 TO 10000 SQ. AREA IS NORMALLY
PROVIDED.
HYDRANTS ARE GENERALLY PROVIDED AT STREET CROSSINGS, WATER
DEMANDS OF ONE LITRE PER HEAD PER DAY IS CONSIDERED FOR FIRE
HYDRANTS. FIRE HYDRANTS ARE OF TWO TYPES PILLAR OR POST HYDRANT
AND SUNK OR FLUSH HYDRANTS.
PILLAR OR POST HYDRANT THESE HYDRANT REMAIN STANDING ABOVE
GROUND LIKE A POST BY ABOUT 0.9 M TO 1.2 M AND CONNECTED TO A
WATER MAIN UNDERGROUND. IT CONSISTS OF A SLUICE VALVE, A DUCK
FOOT BEND, A 65 MM DIA POST ONE, TWO OR THREE OUTLETS. THESE
OUTLETS ARE SPACED AROUND THE PERIPHERY OF THE HYDRANT BARREL
6. FLUSH HYDRANT
THESE HYDRANT ARE INSTALLED UNDERGROUND IN A BRICK OR CAST IRON
CHAMBER WITH ITS TOP COVER SLIGHTLY ABOVE THE STREET LEVEL. LETTER
F.H. ARE INSCRIBED ON THE TOP OF COVER FOR IDENTIFICATION. A FLUSH
HYDRANT CONSISTS OF FOLLOWING COMPONENTS, ONE SLUICE VALVE, A
DUCK-FOOT BEND, A 65 MM DIA INSTANTANEOUS TYPE COUPLING.
INTERNAL FIRE FIGHTING SYSTEM
THE LOCAL SELF GOVT I.E. MUNICIPAL AUTHORITIES HAVE BEEN
EMPOWERED TO MAKE BY LAWS TO PROTECT LIVES & PROPERTIES FOR FIRE
PROTECTION SYSTEM WITHIN THEIR MUNICIPAL LIMITS. THESE BYLAWS ARE
GENERALLY BASED ON NFPA (NATIONAL FIRE PROTECTION ACT).
RESIDENTIAL PREMISES FIRE PROTECTION SYSTEM
FIRE HOSE SYSTEM DRY RISER/ WET RISER
AUTOMATIC SPRINKLER SYSTEMS
POTABLE FIRE EXTINGUISHERS,
FIRE ALARM SYSTEMS
INDUSTRIAL FIRE FIGHTING SYSTEM
HIGH VELOCITY WATER SPRAY
MEDIUM VELOCITY FIRE SPRAY
FOAM
DRY CHEMICAL POWDER
CARBON DIOXIDE
ALARM GONG
PORTABLE FIRE EXTINGUISHER
FIRE ALARM SYSTEM
7. THIS SYSTEM INVOLVES THE INSTALLATION OF VERTICAL RISER PIPE WITH
HOSE CONNECTIONS AT STRATEGIC POINTS THROUGHOUT THE BUILDING.
THE STANDPIPE OR RISER CAN BE KEPT FILLED WITH WATER IS KNOW AS WET
RISER SYSTEM OTHERWISE IT IS KNOWN AS DRY RISER SYSTEM
FIRE HOSE SYSTEM
HOSE
SYSTEM
DRY RISER SYSTEM
A DRY RISER SYSTEM OR DRY PIPE SYSTEM IS MADE OF COMPLETE WATER-
DISTRIBUTION SYSTEM WITH SPRINKLER HEAD OR RISERS AND BRANCHES
WITH HYDRANTS THROUGHOUT THE BUILDINGS IN WHICH THERE IS NO
RUNNING WATER.
IN THE SPRINKLER SYSTEM THE DRY PIPE SYSTEM IS USED PARTLY TO
PROTECT THE INTERIOR OF THE BUILDINGS AGAINST HAZARDS OF BURST
AND LEAKY PIPE TO AVOID FREEZING OF WATER IN THE PIPES.
WATER IS TURNED INTO WATER DISTRIBUTION SYSTEM EITHER
AUTOMATICALLY OR MANUALLY ON THE OUTBREAK OF FIRE OR THE
SOUNDING OF ALARM GONG TO SMOTHER OR EXTINGUISH FIRE.
WHEN THE FUSE MELTS IN DUE TO THE HEAT GENERATED BY FIRE, WATER
GUSHES IN AND AIR EXHAUSTED THROUGH THE SPRINKLER HEAD QUICKLY.
IN THE PREACTION SYSTEM WATER IS ADMITTED TO THE SYSTEM BY A VALVE
ACTUATED BY A THERMOSTATIC CONTROLLED DEVICE THAT FUNCTION IN
ADVANCE OF THE SPRINKLER SYSTEM.
THE DISTRIBUTION SYSTEM IS LAID WITH A SLOPE OF ABOUT 1:200, SO THAT
THE COMPLETE WATER IS DRAINED OUT OF THE SYSTEM.
PROVISION OF NECESSARY PRESSURE GAUGES IS MADE ON MAIN WATER
SUPPLY, DISTRIBUTION, AIR TANK, PUMPS, ETC.
8. WET RISER SYSTEM
THE PROVISION OF WET RISER SYSTEM WHENEVER MADE FOR
RESIDENTIAL BUILDING SHOULD HAVE THE FOLLOWING FEATURES:
THE WET RISER ARE DESIGNED FOR ZONAL DISTRIBUTION OF WATER
ACCORDING TO HEIGHT OF BUILDING
THE FIRST RISER UP TO 60 M HEIGHT SHOULD BE 10 CM DIA
THE SECOND RISER UPTO 100M HEIGHT OF 15 CM DIA
THE THIRD RISER UPTO 150 M HEIGHT OF 15 CM DIA
THESE RISERS ARE CONNECTED TO FIRE PUMPS SEPARATELY PROVIDED FOR
THIS PURPOSE IN THE BUILDINGS
A WET RISER MUST BE PROVIDED NEAR THE ENCLOSURE STAIRCASE.
THE PIPE FITTING SHOULD BE APPROVED MAKE AND QUALITY BY THE
COMPETENT AUTHORITY.
AUTOMATIC SPRINKLER SYSTEM
AUTOMATIC SPRINKLERS ARE CONNECTED TO A WATER DISTRIBUTION
SYSTEM. A SPRINKLER NOZZLE IS CLOSED BY A FUSIBLE PLUG THAT MELTS AT A
PREDETERMINED TEMPERATURE, ABOVE NORMAL ROOM TEMPERATURE,
RELEASING WATER TO FALL ON THE SOURCE OF HEAT.
9. SPRINKLERS HAVE THE ADVANTAGE OF QUICKLY SUPPLYING WATER TO FIRE
BEFORE IT GAIN DANGEROUS HEADWAY AND OF PREVENTING THE ACCESS OF
AIR TO THE FIRE BY SMOTHERING IT WITH WATER.
IN SOME CASES AN OPEN HEAD SPRINKLER SYSTEM FOR THE PROTECTION
OF THE INTERIOR OF THE BUILDING IS PROVIDED
SPRINKLER CLASSIFICATION
SPRINKLER BASED ON RELEASE
FUSABLE ELEMENT SPRINKLER IS OPENED UNDER THE INFLUENCE OF HEAT
BY THE MELTING OF EUTECTIC METAL OR CHEMICAL
GLASS BULB SPRINKLERS ARE OPENED UNDER THE INFLUENCE OF HEAT BY
THE DESTRUCTION OF THE GLASS BULB THROUGH PRESSURE OF THE FLUID
ENCLOSED THEREIN.
GLASS BULB SPRINKLERS
CONVENTIONAL SPRINKLER
THE CONVENTIONAL SPRINKLER HAVE A SPHERICAL WATER DISTRIBUTION
DIRECTED TOWARDS THE GROUND AND THE CEILING FOR THE DEFINITE
PROTECTION AREA
SIDEWALL SPRINKLER
THE SIDEWALL SPRINKLER HAS A ONE –SIDED HALF-PARABOLIC WATER
DISTRIBUTION DIRECTED TOWARDS THE GROUND FOR A DEFINITE
PROTECTION AREA
10. INDUSTRIAL FIRE FIGHTING SYSTEM
THE CAPACITY FOR WATER STORAGE TANK FOR FIRE FIGHTING OF AN
INDUSTRIAL BUILDING IS WORKED OUT AT A RATE OF 2.5 LIT/SQM. OF
LATTABLE FLOOR AREA SUBJECTED TO MINIMUM OF 2,25000 LITRES. A SET
OF TWO PUMPS MUST BE INSTALLED TO DISCHARGED 2275 LITRES PER MIN
AT A PRESSURE OF 3.5 KG/CM2 AT A DESIRED FLOOR.
LIGHT HAZARD OCCUPANCIES: BUILDINGS WITH LOWER HAZARD SUCH
AS SCHOOL, HOSPITALS, HOTELS.
ORDINARY HAZARD OCCUPANCIES: CONSISTING OF THE MAJORITY OF
THE COMMERCIAL AND INDUSTRIAL BUILDINGS
HIGH HAZARD OCCUPANCIES: THESE OCCUPANCIES ARE DIVIDED INTO:-
PROCESS RISKS SUCH AS PAINT, FOAM, PLASTIC AND FOAM RUBBER
HIGH PILED STORAGE RISES IN PETROLEUM PRODUCTS.
METHODS OF FIRE EXTINGUISHING
FOAM SYSTEM
FOAM SYSTEM HAS EARNED RECOGNITION AS
A EFFECTIVE METHOD. FOAM SYSTEMS ARE
SPECIALLY SUITED FOR FIRES IN OIL STORAGES,
FLAMMABLE LIQUIDS SUCH AS BENZOYL,
PETROL, ALCOHOL, AND LIGHTER PETROLEUM
PRODUCTS. IN THIS SYSTEM FLUROPROTEIN
FOAM COMPOUNDS IS APPLIED FORCEFULLY.
TO BURNIN HYDROCARBON LIQUID WHICH PROHIBITS FIRE SPREAD. THIS
SYSTEM IS GENERALLY OPERATED MANUALLY
DRY CHEMICAL POWDER
DRY CHEMICAL POWDER USED TO COMBAT FIRES IN FLAMMABLE LIQUIDS,
GASES AND GREASES INCLUDE SUCH FIRES WHEN INVOLVED WITH
ENERGIZED ELECTRICAL EQUIPMENT IS A POTASSIUM BICARBONATE BASED
DRY CHEMICAL. THE CHEMICAL POWDER IS FREE FLOWING, WATER
REPELLENT AND NON ABRASIVE AND WHEN USED AS A FIRE EXTINGUISHER
AGENT WILL PRODUCE NO TOXIC EFFECTS. BECAUSE OF ITS EXCELLENT FIRE
FIGHTING EFFECTIVENESS THIS PRODUCT IS WIDELY USED IN OTHER HIGH
RISK AREAS.
CARBON DIOXIDE OR NITROGEN IS USED AS A EXPELLING GAS. THIS SYSTEM
CAN BE EFFECTIVELY INSTALLED IN RESTAURANTS, FUEL STATIONS ETC
11. CARBON DIOXIDE
CARBON DIOXIDE HAS BEEN USED FOR MANY YEARS
TO EXTINGUISH THE FLAMMABLE LIQUID FIRES AND
FIRE INVOLVING ELECTRICALLY ENERGIZED
EQUIPMENT'S. CARBON DIOXIDE ABOUT ONE AND
HALF TIMES AS HEAVY AIR, A PROPERTY THAT
ACCOUNTS FOR ITS ABILITY TO REPLACE AIR ABOVE
BURNING SURFACE AND MAINTAIN A SMOTHERING
ATMOSPHERE, IT IS NON COMBUSTIBLE AND DOES
NOT REACT WITH MOST SUBSTANCES.
a) SMOTHERING EFFECT
•CARBON DIOXIDE IS STORED UNDER PRESSURE AS LIQUID, WHEN RELEASED, IT
IS DISCHARGED INTO THE FIRE AREA PRINCIPALLY AS A GAS. WHEN RELEASED
ON BURNING MATERIAL, IT COVERS THEN AND REMOVES THE OXYGEN TO A
CONCENTRATION WHICH CANNOT SUPPORT COMBUSTION
b) COOLING EFFECT
•THE RAPID EXPANSION OF LIQUID TO GAS WHEN CARBON DIOXIDE IS
RELEASED FROM STORAGE CYLINDER PRODUCES A REFRIGERATING EFFECT
THAT CONVERTS PART OF THE CARBON DIOXIDE INTO SNOW. THIS SNOW,
WHICH HAS A TEMPERATURE OF 80 0C SOON SUBLIMES INTO GAS, ABSORBING
HEAT FROM THE BURNING MATERIAL AND SURROUNDING ATMOSPHERE
ESCAPE CHUTE
•AN ESCAPE CHUTE IS A SPECIAL KIND OF EMERGENCY EXIT, USED WHERE
CONVENTIONAL FIRE ESCAPE STAIRWAYS ARE IMPRACTICAL. THE CHUTE IS A
FABRIC (OR OCCASIONALLY METAL) TUBE INSTALLED NEAR A SPECIAL EXIT ON
AN UPPER FLOOR OR ROOF OF A BUILDING, OR A TALL STRUCTURE. DURING
USE, THE CHUTE IS DEPLOYED, AND MAY BE SECURED AT THE BOTTOM BY A
FIRE FIGHTING CREW SOME DISTANCE OUT FROM THE BUILDING. ONCE THE
TUBE IS READY, ESCAPEES ENTER THE TUBE AND SLIDE DOWN TO A LOWER
LEVEL OR THE GROUND LEVEL.
ESCAPE
CHUTE
Editor's Notes
Siamese twins: conjoined twins (= two people with the same mother who were born at the same time