Disclosure to Promote the Right To Information Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public. इंटरनेट मानक “!ान $ एक न’ भारत का +नम-ण” Satyanarayan Gangaram Pitroda “Invent a New India Using Knowledge” “प0रा1 को छोड न’ 5 तरफ” Jawaharlal Nehru “Step Out From the Old to the New” “जान1 का अ+धकार, जी1 का अ+धकार” Mazdoor Kisan Shakti Sangathan “The Right to Information, The Right to Live” “!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता ह ै” Bhartṛhari—Nītiśatakam “Knowledge is such a treasure which cannot be stolen” IS 15528 (2004): Gaseous Fire Extinguishing Systems - Carbon Dioxide Total Flooding and Local Application ( Sub-Floor and In-Cabinet), High and Low Pressure (Refrigerated) Systems [CED 22: Fire Fighting]
Transcript
Disclosure to Promote the Right To Information
Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.
इंटरनेट मानक
“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda
“Invent a New India Using Knowledge”
“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru
“Step Out From the Old to the New”
“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan
“The Right to Information, The Right to Live”
“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam
“Knowledge is such a treasure which cannot be stolen”
“Invent a New India Using Knowledge”
है”ह”ह
IS 15528 (2004): Gaseous Fire Extinguishing Systems -Carbon Dioxide Total Flooding and Local Application (Sub-Floor and In-Cabinet), High and Low Pressure(Refrigerated) Systems [CED 22: Fire Fighting]
IS 15528:2004
Indian Standard
GASEOUS FIRE EXTINGUISHING SYSTEMS —CARBON DIOXIDE TOTAL FLOODING AND
LOCAL APPLICATION ( SUB-FLOOR ANDIN-CABINET ), HIGH AND LOW PRESSURE
( REFRIGERATED) SYSTEMS
ICS 13.220.10
(3 BIS 2004
BUREAU OF INDIAN STANDARDSMANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002
Price Group 8
Fire Fighting Sectional Committee, CED 22
FOREWORD
This lndian Standard was adopted by the Bureau of Indian Standards, after the draft finalized by the FireFighting Sectional Committee had been approved by the Civil Engineering Division Council.
This standard is intended for use by those concerned with purchasing, designing, installing, testing, inspecting,approving, and operating carbon dioxide ( C07 ) total flooding and local application extinguishing systems, inorder that such equipment/system will function as intended throughout its life.
It is important that the fire protection of a building or plant be considered as a whole. Carbon dioxide systemsI_orm only a part, though an important part, of the available fire protection facilities. However, it should not beassumed that their adoption necessarily removes the need to consider supplementary measures, such as theprovision of portable fire extinguishers or mobile appliances for first aid or emergency use, or measures to deal\vitll special hazards.
Carbon dioxide is recognized as effective for extinguishing Class B fires and where electrical risks are present.I Iowever, it should not be forgotten in the planning of comprehensive schemes that there may be hazards forwhich this technique is not suitable, or that, in certain circumstances or situations, there may be dangers in itswse, requiring special precautions.
The discharge of carbon dioxide creates a dangerous oxygen deficiency, which may result in unconsciousness~ind subsequent suffocation, Carbon dioxide should be used normally in unoccupied area.
Advice on the above can be obtained from organizations involved with the installation of carbon dioxide totalflooding systems.
The objective of this standard is to provide the users of carbon dioxide systems specific requirements forthe control of fires of Class B type. It does not cover the design of explosion suppression systems.
It is essential that fire extinguishing equipment be carefully maintained to ensure instant readiness when required.
The importance of maintenance cannot be too highly emphasized.
This standard has been prepared to meet the need for the dissemination of information on establishedsystem design, Its requirements represent the best technical data known at the time of preparation but, since awide field is covered, it has been impracticable to consider every possible factor or circumstance that mightaffect implementation.
It is a basic assumption that this standard be used only by persons competent in the field of application withwhich it deals. This is of particular importance in fire protection work, Accordingly, it is emphasized that the
design requirements in this Standard are to be interpreted only by trained and experienced designers.
This standard does not include specific requirements for carbon dioxide systems for marine applications. However,
the method of calculation in this standard may be of some assistance in the design of such systems.
IS 15528:2004
Indian Standard
GASEOUS FIRE EXTINGUISHING SYSTEMS —CARBON DIOXIDE TOTAL FLOODING AND
LOCAL APPLICATION ( SUB-FLOOR ANDIN-CABINET ), HIGH AND LOW PRESSURE
( REFRIGERATED) SYSTEMS
1 SCOPE
1.1 This standard lays down the requirements for
carbon dioxide systems, utilizing high pressure orrefrigerated low pressure carbon dioxide as the fire
extinguishant system.
1.2 The carbon dioxide shall comply with therequirements of IS 15222.
1.3 General principles may well apply for other uses
such as in-cabinet subfloor for which additionalconsiderations may have to be taken into account.
2 REFERENCES
The standards listed in Annex A contain provisionswhich through reference in this text, constitute
provisions of this standard. At the time of publication,the editions listed were valid. All standards are subject
to revision and the parties to agreements based onthis standard are encouraged to apply the most recenteditions of the standards indicated in Annex A.
3 DEFINITIONS
For the purpose of this standard, the definitions given
in IS 15493 shall apply.
4 USES AND LIMITATIONS OF CARBONDIOXIDE
4.1 General
The extinguishing medium corbon dioxide is acolorless, odourless and electrically non-conductivegas. Carbon dioxide is approximately one and a halftimes heavier than air.
Carbon dioxide extinguishes fires principally byreducing the oxygen content in the atmosphere to a
point where it will not support combustion.
The relationship between the temperature and
pressure of liquid carbon dicxide is shown in Fig. 1,At31 “C, the liquid and vapour have the same density,and of course the liquid phase disappears. This iscalled critical temperature of carbon dioxide.
NOTE — Carbon dioxide concentrations, as requiredfor use in extinguishing systems, pose hazards to personnel
1
due to obscuration of vision and reduction of oxygenconcentrations below that which wi II not support Iife,not only in the immediate area of discharge, but also inadjacent areas to which the gas may migrate. Therefore,the safety requirmlents given in 5.1 shall be strictlyobserved.
4.2 Uses of Carbon Dioxide
Carbon dioxide is suitable for extinguishing thefollowing types of fire:
a)
b)
c)
d)
Under certain conditions, fires involvingcarbonaceous solid materials, usually of anorganic nature, in which combustion normally
takes place with the formation of glowingembers ( Class A fires ).
Fires involving flammable and combustibleliquids ( .Class B fires).
Fires involving combustible gases, exceptwhen, after extinguishment, an explosiveatmosphere may develop due to a
continuation of escaping gases ( Class Cfires ).
Fires involving live electrical apparatus.
4.3 Limitations of Carbon Dioxide Systems
Carbon dioxide systems are not suitable for use onfires involving the following:
a) Chemicals containing their own supply ofoxygen, such as cellulose nitrate.
b) Reactive lmetals and their hydrides ( forexample, sodium, potassium, magnesium,titanium and zirconium ).
5 SAFETY REQUIREMENTS
5.1 Safety of Personnel
5.1.1 Protection ofOccupants
The discharge of carbon dioxide in fire extinguishingconcentration creates serious hazards for personnel,such as reduced visibility and suffocation, during andafter discharge period. Suitable safeguards shall alsobe provided to ensure prompt evacuation, to prevententry into such areas and provide a means for prompt
FIG. 1 VARIATIONOF PRFSSURE OF CARBON DIOXIDE wnm CHANCE IN TEMPERATIJRE( CONSTANTVOLIJME )
rescue of any trapped personnel.
5.1.2 Precautions for Enlet-ing Confined Spaces andLow Lyit7g A i-eas
Entry into confined spaces poses additionalhazards because of restrictions on freedom ofmovement, ventilation, escape or rescue. Before entryinto floor and ceiling voids, ducts, process vessels
or similarly confined spaces, the automatic release of
2
the system shall be isolated and the lock-off controlactivated.
Entry into confined spnces for any purpose shall becontrolled by a permit-to-work system. Provisionsshall be made for ensuring that the atmosphere withinthe space is safe for entry and shall remain so for theduration of entry. In cases where effective ventilationcannot be ensured, the permit shall specify therespiratory protective equipment to be used and any
IS 15528:2004
other special precautions to be observed to ensuresafe working conditions.
Where it is possible for carbon dioxide gas to collectin low-lying areas, pits, wells and shaft bottoms,consideration shall be given to adding an odoriferoussubstance to the carbon dioxide. In such areas, theinstallation of additional ventilation systems shall beconsidered.
5.1.3 Entry to Protected Areas
Entry into a protected area shall normally only be madewhen the total flooding system has been placed under
manual control by means of a Iock-offvalve.
5.2 Safety Precautions
5.2.1 General
The minimum safety precautions associated withthe use of carbon dioxide at fire extinguishingconcentrations are as follows:
a) Inhibit switch and time delay ( with alarmhooter ),
b) Safety interlock, and
c) Lock-off valve.
5.2.2 Electrical Clearance
All system components shall be so located as tomaintain minimum clearance from live parts as perTable 1.
5.2.3 Electrostatic Discharge
The discharge of liquid carbon dioxide is known toproduce electrostatic charges which, under certain
conditions, could create a spark. Carbon dioxide fireextinguishing systems protecting areas whereexplosive atmospheres couId exist shall utilize metalnozzles and be properly bonded and earthed. Inaddition, objects exposed to discharge from carbon
dioxide nozzles shall be earthed to dissipate possibleelectrostatic charges. Where pipe work is to be bondedand earthed, it shall colmply with IS 7689.
6 SYSTEM DESIGN
6.1 General
The requirements for total flooding systems andthose for local application systems are given in 6.2
to 6.18.
6.2 Total Flooding Systems Basis for Design
The construction of the enclosure to be protected
by carbon dioxide total flooding systems shall besuch as to prevent ready escape of the gas. Openingsand ventilation systems shall be closed or shut
down automatically before, or at leastsimultaneously with, initiation of discharge of thecarbon dioxide, and remain shut. Where openingscannot be shut or where there is an absence ofwalls or ceilings, additional carbon dioxide quantitiesshall be provided as specified in 6.7. Openings to
Table 1 Clearance from Carbon Dioxide Equipment to Live Uninsulated Electrical Components
( Clause 5.2.2)
S1 No. Nominal System Maximum System Design Basic Minimum ClearanceVoltage, kV Voltage, kV Insulation Level, kV mm
(1) (2) (3) (4) (5)
i) up to 15.8 14.5 110 178
ii) 23 24.3 150 254
iii) 34.5 36,5 200 330
iv) 46 48,3 250 432
v) 69 72,5 350 635
vi) 115 121 550 1067
vii) 138 145 650 1270
viii) 161 169 750 1 473
ix) 230 242 900 19301 050 2134
x) 345 362 1 050 2134I 300 2642
xi) 500 550 1 500 3 1501 800 3658
xii) 765 800 2050 4 242
NOTE — The clearance is the air distance between equipment, including piping and nozzles, and unenclosed or un-insulated live electrical components at other than ground potential.
3
1S 15528:2004
the outside atmosphere, where wind conditions mayaffect the carbon dioxide losses, might necessitatespecial consideration.
Examples of hazards and their enclosures that canbe successfully protected by total flooding systemsinclude rooms, vaults, enclosed machines, ducts, ovens,containers, and their contents.
6.3 Design Quantity of Carbon Dioxide
6.3.1 Factors to be Considered
To determine the quantity of the carbon dioxiderequired, the volume of the room or of the enclosureto be protected shall be taken as a basis. From thisvolume only, solid structural members, such asfoundations, columns and beams, are to be deducted.The following shall be taken into account:
a) Room size,
b) Material to be protected,
c) Particular risks,
d) Openings that cannot be closed,
e) Ventilation systems which cannot be shut
down, and
f) Temperature of protected area.
For flash or surface type fires, such as will be presentwith flammable liquids, any non-closing openings shall
be compensated for by additional carbon dioxide asspecified in 6.4.5. If the quantity of carbon dioxiderequired for compensation exceeds the basic quantitiesrequired for flooding without leakage, the systemshall be designed for local application in accordancewith 7.
For deep-seated fires such as those involving solids,non-closing openings shall be restricted to thosebordering on, or actually in the ceiling, if the size ofthe openings exceed the pressure relief ventingrequirements set out in 6.5.
To prevent fire from spreading through openings
to adjacent hazards or work areas, which may bepossible reignition sources, such openings shall beprovided with automatic closures or local applicationnozzles. The gas required for such protection shallbe in addition to the normal requirement for totalflooding ( see 6.15). When neither method is practical,protection shall be extended to include these adjacenthazards or work areas.
In the case of process and storage tanks, where safeventing of flammable vapours and gases cannot berealized, external local application systems are usedfor protection across the openings, and the area pernozzle given by specific approval or listing may be
increased by 20 percent.
6.3.2 Leakage and Ventilation
Since the efficiency of carbon dioxide systems dependsupon the maintenance of an extinguishing concentrationof carbon dioxide, leakage of gas from the area shallbe kept to a minimum and compensated for by applying
extra gas.
Where possible, openings such as doorways andwindows shall be arranged to close automatically beforeor simultaneously with the start of the carbon dioxidedischarge, or the requirements of 6.7 and 6.11 shallbe followed. For personnel safety, see 5.1.
Where air handling ventilation systems are involved,they shall be shut down or isolated by dampers, orboth, before or simultaneously with the start of thecarbon dioxide discharge. Where this is not practical,
additional compensating gas shall be provided.
6.3.3 Types of Fires
Fires which can be extinguished by total floodingmethods can be divided into two categories,namely:
a) Surface fires involving flammable liquids,gases and solids; and
b) Deep-seated fires involving solids subjectto shouldering.
Surface fires are the most common hazard suitablefor extinguishment by total flooding systems. They
are extinguished promptly when carbon dioxide isintroduced into the enclosure in sufficient quantity
both to overcome leakage and to provide anextinguishing concentration suitable for theparticular materials involved.
For deep-seated fires, the extinguishing concentrationshall be maintained for a sufficient period to allowthe shouldering to be extinguished and the materialto cool to a point at which reignition will not occur
after dissipation of the inert atmosphere.
6.3.4 Pressure Adjustment
The quantity of carbon dioxide shall be adjusted
to compensate for ambient pressures that varymore than 11 percent ( equivalent to approximately915 m of elevation change ) from standard sea levelpressure ( 760 mm Hg ). The ambient pressure isaffected by changes in altitude, pressurization ordepressurization of the protected enclosure,and weather-related barometric pressure changes.The adjusted storage quantity is determined bymultiplying the number of carbon dioxide containers(IV), determined in accordance with 6.2, by the ratioof average ambient enclosure pressure to standardsea level pressure. The atmospheric correction factorsare given in Table 2.
4
IS 15528:2004
Table 2 Atmospheric Correction Factors
( Clause 6.3.4)
S1 No.
(1)
i)
ii)
iii)
iv)
v)
vi)
EquivalentAltitude
M
(2)
–0.920-0.610-0.300
0,000
0.3000,6100.920
1.2201.5201.830
2.1302.4402.740
3.050
EnclosurePressure
mndHg
(3)
840812787
760
733705678
650622596
570550528
505
AtmosphericCorrection
Factor
(4)
1.111.071.04
1.00
0.960.930.89
0.860.820.78
0.750.720,69
0.66
6.4 Carbon Dioxide Requirements for Surface Fires
6.4.1 General
The quantity of carbon dioxide for surface fires is based
on average conditions assuming reasonably promptextinguishment. An allowance for normal leakage isincluded in the basic volume factors, but corrections
shall be made for the type of material involved andfor any other special conditions.
6.4.2 Flammable Materials
Consideration shall be given to the determinationof the design concentration of carbon dioxiderequired for the type of flammable material
involved in the hazard. The design concentrationis determined by adding a suitable factor
(30 percent ) of the theoretical minimum concentration.In no case shall a concentration of less than 34 percent
be used.
Table 3 gives the theoretical minimum carbon dioxideconcentration to prevent ignition of some commonliquids and gases.
For materials not given in Table 3, the minimum
theoretical carbon dioxide concentration shall beobtained from a recognized source or determined
by test. If accepted residual oxygen values areavailable, the theoretical carbon dioxideconcentration shall be calculated by the followingequation:
21–02Percent, C02 = x 100
21
6.4.3 Volume Factor
The volume factor used to determine the basic quantity
of carbon dioxide to protect an enclosure containinga material requiring a design concentration of34 percent shall be in accordance with Table 4.
The quantity of COj required shall be further calculatedto compensate for any special conditions, such asunclosable openings, forced ventilation, the free volumeof air receivers that may discharge into the risk, altitude( substantially above or below sea level ) or any othercauses for the extinguishant loss.
As the average small space has proportionallymore boundary area per enclosed volume than alarger space, proportionally greater leakages are
anticipated and accounted for by the graded volumefactors in Table 4.
The least gas quantities for the smallest volumes aretabulated to clarify the intent of COI 2 and 3 ofTable 4 and thus avoid possible overlapping at
borderline volumes.
In two or more interconnected volumes in which the‘free flow’ of carbon dioxide is likely to take place,
the carbon dioxide quantity shall be the sum of thequantities calculated for each volume, using itsrespective volume factor from Table 4. If one volume
requires greater than normal concentration, the higher
concentration shall be used in all interconnectedvolumes.
6.4.4 Material Conversion Factor
For materials requiring a design concentration ofmore than 34 percent, the basic quantity of carbondioxide calculated from the volume factor givenin Table 4 shall be increased by multiplying thisquantity by the appropriate conversion factor given
in Fig. 2.
6.4.5 Special L’onditions — Total Flooding Systems
6.4.5.1 General
Additional quantities of carbon dioxide shall be
provided to compensate for any special conditionsthat may adversely affect the extinguishing efficiencyof the system.
6.4.5.2 Unclosable openings
Any openings that cannot be closed at the time of
extinguishment shall be compensated for by theaddition ofa quantity of carbon dioxide equal to theanticipated loss at the design concentration duringa 1 min period. This amount of carbon dioxide shallbe applied through a regular distribution system( see 6.5 and 6.6 ). For ventilating systems thatcannot be shut down, additional carbon dioxide
5
IS 15528:2004
Table 3 Minimum Carbon Dioxide Concentrations for Extinguishment
1 The theoretical minimum extinguishing concentrations in air for the above materials II ere obtained from a compilationof USA Bureau of Mines’ Limits of flammability of gases and vapours ( Bu]]etins 503 and 627 ).
2 Concentrations calculated from accepted oxygen values,
shall be added to the space through the regular when the design concentration is greater than 34distribution system, in an amount computed by dividing percent.the volume moved during the liquid discharge period
by the flooding factor. This shall be rntiltiplied by 6.4.5.3 High tenzpevut~me
the material conversion factor ( determined in Fig. 2 ) For applications where the normal temperature of the
6
Table 4 Flooding Factors
( Clauses 6.4.3 and6.4.4 )
AVolume of
Space1113
(1)
4
4 to 15
15 to 46
47 to 130
131(0 1400
> 1 400
BVolume Factor
\
m~lkg CO, kg CO@3
(2) - (3)
0.86 1.15
0.93 1.07
0.99 1.01
1,11 0,90
1.25 0.80
1.38 0.77
c:CalculatedQuantity
+ kg
(4)
4.5
15.1
45.4
I 13.5
I 135,0
enclosure is above 93°C, hazards may be moresusceptible toreignition. Therefore, additional carbondioxide is advisable to hold the extinguishing
concentrations for a longer period of time, allowingthe extinguished material to cool down and therebyreduce the chance of reignition when the carbondioxide dissipates.
One percent increase in the calculated total quantityof C02 shall be provided for each additional 5°F above200°F ( 93°C ).
IS 15528:2004
6.4.5.4 Low tetnperalure
For applications where the normal temperature ofthe enclosure is below– 8°C at one percent increasein the calculated total quantity of carbon dioxide shallbe provided for each 2.3°C below-1 8°C.
6.5 Carbon Dioxide Requirements for Deep-SeatedFires
6.5.1 General
The quantity of carbon dioxide for deep-seated
type fires is based on tight enclosures. After the designconcentration is reached, the concentration shallbe maintained for a substantial period but not lessthan 20 min. Any possible leakage shall be givenspecial consideration since no allowance is includedin the basic flooding factors.
6.5.2 Combustible Materials
For combustible materials capable of producing
deep-seated fires, the carbon dioxide concentrationscannot be determined with the same accuracy assurface burning materials. The extinguishingconcentration will vary with the mass of materialpresent because of the thermal insulating effects.Flooding factors have therefore been determined on
5
4
~
u$3
zozlx>
82c1
130 34 40 50 60 70 80 90
MINIMUM DESIGN C02 CONCENTRATION, PERCENT
FIG. 2 MArERIAL CONVERSIONFAC-IORS
7
IS 15528:2004
the basis of practical test conditions.
The design concentrations in Table 5 shall be achievedfor the hazards listed. Generally, the floodingfactors in Table 5 provide the design concentrationfor the rooms and enclosures listed.
Flooding factors for other deep-seated fires shall bejustified to the satisfaction of the appropriate authoritybefore use. Consideration shall be given to the massof material to be protected because the rate of coolingis reduced by the thermal insulating effects.
6.5.3 Volume Consideration
When calculating the net cubic capacity to beprotected, allowance should be made for the
reduction of volume by permanent non-removableimpermeable structures materially reducing thevoi Lime.
The basic quantity of carbon dioxide required toprotect an enclosure shall be obtained by treating the
volume of the enclosure by the appropriate floodingfactor given in 6.4.2.
6.5.4 Special Conditions
6.5.4.1 General
Additional quantities of carbon dioxide shall be
provided to compensate for any special conditionsthat may adversely affect the extinguishing efficiency( see 6.3.2,6.3.3 and 6.3.4).
6.5.4.2 Unclosable openings
Any openings that cannot be closed at the time ofextinguishment shall be compensated for by theaddition of carbon dioxide equal in volume to theexpected leakage volume dyring the extinguishingperiod. If leakage is appreciable, considerationshall be given to an extended discharge system( see 6.7).
6.6 Rate of Application
The minimum design rate of application shall be basedon the quantity of carbon dioxide and the maximumtime to achieve design concentration as follows:
a) For surface fires, the design concentrationshall be achieved within 1 min.
b) For high pressore systems, if a part of thehazard is to be protected by local
application, the discharge rate for the totalflooding portion shall be calculated asspecified in 6.12.
c) For deep-seated fires, the designconcentration shall be achieved within1 min and maintained for 7 rnin, but the rateshall be not less than that required to
develop a concentration of 30 percentin 2 min.
6.7 Extended Rate of Application
Where leakage is appreciable and the designconcentration must be obtained quickly and maintainedfor an extended period of time, carbon dioxide providedfor leakage compensation may be applied at a reducedrate.
Figure 3 maybe used as a guide in estimating discharge
systems.
6.7.1 This type of system is particularly applicableto enclosed rotating electrical apparatus, such asgenerators, motors and converters, but it may alsobe used on ordinary total flooding applications where
suitable.
6.7.2 The minimum design concentration shall beobtained within the time limits specified in 6.6(c).
6.7.3 The extended rate ofdischarge shall be sufficientto maintain the minimum concentration.
Table 5 Flooding Factors for Specific Hazards
(Clause 6.5.2)
SI No. Design Concentration Flooding Factor Specific Ilazarxt,-m~lkg C02
iii) 65 0.50 ( 9 I kg ) Min Bulk paper storage, ducts, and2.00 covered trenches
iv) 75 0.38 2.66 For storage vaults, dostcollectors
8
IS 15528: 2004
489.00440.10391.20342.30293.40
244.60
195.60
146.70
N
: 97.80.-E
g
2~“ 48.90
5 ‘w;& 34,23~ 29.34
j 24.45
19.58
~4.67
9.78
l=” 1 1 I I 1 I I xl
I
4 Iv4 v 1 I I I I I I ! I I I 1 I 1 I I I 1----0.3 0.6 0.9 1.2 1.51.821,2 .42!73.1 6.1 9.2 12.21 ~,318~124j731
HEIGHT OF ATMOSPHERE ABOVE CENTRE OF OPENING, METRES
FIG. 3 CALCULATEDC02 Loss RATE BASED ON AN ASS[JM~D21 “C TEMPERATURE
WITHIN THEENCLOSUREAND21 “C AMBiIiNI- OUTSIDE
6.7.4 For enclosed rotating electrical equipment, aminimum concentration of 30 percent shall bemaintained for the deceleration period, but not lessthan 20 min.
6.8 Piping Systems
Piping shall be designed in accordance with 8 andIS 15493 to deliver the required rate of application
at each nozzle.
High pressure storage temperatures can range from–18° to 54°C without requiring special methods of
compensation for changing flow rates.
6.9 Local Application/In-cabinet Subfloor Systems
Local application systems shall be designed, installedand tested in accordance with the applicablerequirements covered in 6.5 and with the additionalrequirements of this clause.
The method for the venting of flammable vapoursand pressure build-up from the discharge ofquantities of carbon dioxide into closed areas shall
be considered. The pressure venting considerationinvolves such variables as enclosure strength andinjection rate.
6.10 Hazard Specification
The hazard shall be isolated from other hazards or
combustibles in such a way that fire will not spreadoutside the protected mea. The entire hazard shall
be protected. The hazard shall include all areas thatare likely to be coated with combustible liquids or
shallow solids coatings, such as areas subject tospillage, leakage, dripping, splashing, or condensation,and all associated materials or equipment, such asfreshly coated stock, drain boards, hoods and ducts,that might extend fire outside or lead fire into theprotected area.
9
IS 15528:2004
A series of connected hazards can be subdivided into portion;
smaller groups or sections with the approval of the lV~ = total quantity of carbon dioxide for theregulatory authority. Systems for such hazards shallbe designed to give immediate independent protection
total flooding portion, in kg; and
to adjacent groups or sections as needed.T~ = liquid discharge time for the local
application portion, in minutes.
6.11 Carbon Dioxide Requirements
The quantity of carbon dioxide required for localapplication systems shall be based on the total rate
of discharge needed to blanket the area or volumeprotected and the time that the discharge must bemaintained to ensure complete extinguishment.
For systems with high pressure storage, the calculatedquantity of carbon dioxide shall be increased by40 percent to establish the nominal cylinderstorage capacity since only the liquid portion of the
discharge is effective. This increase in cylinderstorage capacity is not required for the total flooding
portion of the combined local application of totalflooding systems.
Where long pipelines are involved, or where thepiping may be exposed to higher than normaltemperatures, the quantity shall be increased by anamount sufficient to compensate for liquid vaporizedin cooling the piping.
6.12 Rate of Discharge
Nozzle discharge rates shall be determined by either
the surface method or the volume method as coveredin 6.150 r6.16.
The total rate of discharge for the system shall be the
sum of the individual rates of all the nozzles used onthe system.
For low pressure systems, if a part of the hazard is to
be protected by total flooding, the discharge rate forthe total flooding part shall be sufficient to develop
the required concentration in not more than thedischarge time used for the local application part ofthe system.
For high pressure systems, if a part of the hazard isto be protected by total flooding, the discharge ratefor the total flooding part shall be calculated by dividing
the quantity required for total flooding by the factor1.4 and by the time of the local application dischargein minutes.
The rate of discharge may be calculated using thefollowing equation:
~F= ‘F1.4 TL
where
QF = rate of flow for the total flooding
6.13 Duration of Discharge
The minimum effective discharge time for use in
calculating the quantity shall be 60 s. The minimumtime shall be increased to compensate for any hazardcondition that would require a longer cooling periodto assure complete extinguishment.
Because the tests conducted in the approvals ofcarbon dioxide nozzles will require that fires beextinguished within 20 s, a minimum duration of 30 shas been set for this standard. This allows a safetyfactor for conditions which are unpredictable. It isimportant to recognize that this discharge time is
minimum and that such conditions as high temperatures
and the cooling of unusually hot surfaces within thehazard area require an increase in the discharge time
to ensure complete and effective extinguishment.
Where the fuel has an auto-ignition point below itsboiling point, such as paraffin wax and cooking oils,the effective discharge time shall be increased to permit
cooling of the fuel to prevent reignition. The minimumdischarge time shall be 3 min.
The maximum temperature of a burning liquid fuel
is limited by its boiling point where evaporativecooling matches the heat input. In most liquids,
the auto-ignition temperature is far above theboiling temperature so that reignition afterextinguishment can be caused only by an externalignition source. However, there are a few liquids thathave auto-ignition temperatures much lower thantheir boiling temperatures. Common cooking oils
and melted paraffin wax have this property. Toprevent reignition of these materials, it is necessary
to maintain an extinguishing atmosphere until thefuel has cooled below its auto-ignitiontemperature. A discharge time of 3 min is adequatefor small units, but a longer time is needed for larger
capacity units.
6.14 Rate by Area Method of System Design
6.14.1 General
The area method of system design is used where thefire hazard consists primarily of flat surfaces or low-level
objects associated with plane surfaces.
System design shall be based on listing or approvaldata for individual nozzles. Extrapolation of such data
above or below the upper or lower limits shall not bepermitted.
10
IS 15528:2004
6.14.2 Nozzle Discharge Rates stated in specific approvals.
The design discharge rate through individual nozzles
shall be determined on the basis of location orprojection distance, in accordance with specificapprovals or listings.
The discharge rate for overhead type nozzles shallbe determined solely on the basis of distance fromthe surface each nozzle protects.
6.14.3 Area Protected by Nozzle
Nozzles should be installed perpendicular to thehazard and centred over the area protected by thenozzle. They may also be installed at angles between45° and 90° ( see 3.2 ) from the plane of the hazard
surface as prescribed in 9.8. The distance used indetermining the necessary flow rate and area coverageshall be the distance from the aiming point on theprotected surface to the face of the nozzle measuredalong the axis of the nozzle.
The maximum area protected by each nozzle shall beWhen installed at an angle, nozzles shall be aimed at
determined on the basis of location or projectiona point measured from the nearside of the area protected
distance and the design discharge rate, in accordanceby the nozzle, the location of which is calculated by
with specific approvals or listings.multiplying the fractional aiming factor in Table 6 bythe width of the area protected by the nozzle.
The same factors used to determine the designdischarge rate shall be used to determine the maximum
Table 6 Aiming Factors for Angular Placement of
area to be protected by each nozzle.Nozzles Based on 150 mm Freeboard
The portion of the hazard protected by individual S1 No. Discharge Anglel) Aiming Factorz)
overhead-type nozzles shall be considered as a square (1) (2) (3)
area. i) 45° to 60° ‘/4
The portion of the hazard protected by individual tank
side or linear nozzles shall be either a rectangular ora square area, in accordance with spacing and dischargelimitations stated in specific approvals or listings.
When coated rollers or similar irregular shapes are tobe protected, the projected wetted area shall be usedto determine nozzle coverage.
When coated surfaces are to be protected, the areaprotected per nozzle may be increased by 40 percent
over the areas given in specific approvals or listingsfor a liquid surface. Coated surfaces are defined asthose designed for drainage which are constructed
and maintained so that no pools of liquid will accumulate
over a total area exceeding 10 percent of the protectedsurface. This does not apply where there is a heavybuild-up of residue.
Where local application nozzles are used for protection
across openings, the area per nozzle given by specificapproval or listing may be increased by 20 percent.
ii) 60° to 75° !4 to 3/8
iii) 75° to 90° 3/8 to !4
iv) 90° ( perpendicular ) Y2 centre
l)ln degrees from the plane of hazard surface.‘)The fraction of the width of the area protected.
Nozzles shall be located so as to be free of possible
obstruction that could interfere with the properprojection of the discharged carbon dioxide.
Nozzles shall be located so as to develop anextinguishing atmosphere over coated stock
extending above a protected surface. Additionalnozzles may be required for this purpose, particularlyif stock extends more than 0.6 m above a protected
surface.
The possible effects of air currents, winds and
forced drafts shall be compensated for by properlylocating nozzles or by providing additional nozzlesto protect the outside areas of the hazard
When deep layer flammable liquid fires are to be adequately.
protected, a minimum freeboard of 150 mm shall be 6.15 Rate by Volume Method System Designprovided unless otherwise noted in approvals ofnozzles. 6.15.1 General
6.14.4 Location and Number of Nozzles The volume method of system design is used where
the tire hazard consists ofthree-dimensional irregularA sufficient number of nozzles shall be installed over objects that cannot be easily reduced to equivalentthe entire area on the basis of the unit areas protected surface areas.by each nozzle.
6.15.2 Assumed EnclosureTank side or linear-type nozzles shall be located in
accordance with spacing and discharge rate limitations The total discharge rate of the system shall be based
11
IS 15528:2004
on the volume of an assumed enclosure entirelysurrounding the hazard.
The assumed enclosure shall be based on an actualclosed floor unless special provisions are made to takecare of bottom conditions.
The assumed walls and ceiling of this enclosure shallbe at least 0.6 m from the main hazard unless wallsare involved, and shall enclose all areas of possibleleakage, splashing or spillage.
No deductions shall be made for solid objects withinthis volume.
A minimum dimension of 1.2 m shall be used incalculating the volume of the assumed enclosure.
If the hazard is likely to be subjected to winds or forceddrafts, the assumed volume shall be increased tocompensate for losses on the windward sides.
6.15.3 Total Discharge Rate
The total discharge rate for the basic system shall be
equal to 16 kg/min/m3 of assumed volume.
If the assumed enclosure has a closed floor and is
partly defined by permanent continuous walls
extending at least O.6 m above the hazard ( wherethe walls are not normally part of the’ hazard ), thedischarge rate may be reduced proportionally to notless than 4 kg/min/m3 for actual walls completelysurrounding the enclosure ( see Fig. 4 ).
‘OO h
6.15.4 Location and Number of Nozzles
A sufficient number of nozzles shall be used to
adequately cover the entire hazard volume on the basisof the system discharge rate as determined by theassumed volume. The design discharge rate throughindividual nozzles shall be determined on the basisof location or projection distance.
6.16 Distribution System
6.16.1 General
The system shall be designed to provide prompt andeffective discharge of carbon dioxide before excessive
amounts of heat can be absorbed by materials withinthe hazard.
The carbon dioxide supply shall be located as nearto the hazard as practicable and yet not exposed tothe fire. The pipeline shall be as direct as practicablewith a minimum number of turns in order to get carbondioxide to the fire promptly.
The system shall be designed for automatic operation
except where the appropriate regulatory authority
permits manual operation.
6.16.2 Piping Systems
Piping shall be designed in accordance with 9 to deliverthe required rate of appl ication at each nozzle.
High pressure storage temperatures can range from
?5
75
50
25
04 6 8 10 12 14 16
kg/rein/m 3
FIG. 4 DISCHARGERATE
12
0° to 49°C without requiring special methods ofcompensating for changing flow rates.
7 PROTECTED ENCLOSURE REQUIREMENTS
7.1 Where venting of an enclosure may be necessaryto relieve pressure build-up due to the discharge oflarge quantities of carbon dioxide, the area necessary
for free venting shall be not less than that determinedfrom the following equation:
x
where
~.
Q=
p=
v=
J/l=
K.
2.236 x102x QxV—
Kxfix v“
vent opening area, in mm2;
extinguishant mass flow rate, in kg/rein;
enclosure max. structural safe workingpressure, in kPa;
specific volume of extinguishant at
room temperature and pressure, in
mJ/kg;
specific volume of ventedextinguishantlair mixture in m3/kg; and
orifice flow coefficient ( dimensionless,and usually 0.5 to 0.6 for small openingsin walls ).
If values of V and V] corresponding to 35 percentconcentration and standard room temperature andpressure are substituted, and if X is in mm2 and Q inkg/rein, the equation becomes
247.3x Q/,y.
K@
8 CARBON DIOXIDE SUPPLY
8.1 Quality
The extinguishant used shall be carbon dioxidecomplying with the requirements of IS 15222.
A non-combustible, non-toxic trace gas that is
compatible with the extinguishant and the materialsof construction maybe added to the charge to facilitateleak testing.
8.2 High-Pressure Systems
8.2.1 Storage Containers
The carbon dioxide supply shall be stored in
containers designed to hold carbon dioxide. Thecontainers shall comply with the following:
a) Requirements as per IS 8198 ( Part 1 ) andIS8198(Part3)
b) The container shall be internally dry andbe filled with dry carbon dioxide to themaximum filling ratio of 0.667 within a
IS 15528:2004
tolerance of ‘~~ ~ percent the mass being
determined by w~ighing.
NOrE — The tilling ratio is the ratio of mass of liquefiablegas in the containers to lhe mass of water the containerwill hold at 15”C’.
Where the container design does not incorporate a
safety pressure relief device, it shall be incorporatedin the container valve.
8.2.2 Storage Container Arrangement
The arrangement of storage containers and accessoriesshall be as follows:
a)
b)
c)
The necessary carbon dioxide quantityshall be contained in one bank. The supplyto separate distinct hazards could be froma single bank where there is no likelihood
of the fire spreading from one hazard toanother and provided that the cylinder bankis not placed within any of the hazards. The
total quantity of the bank shall correspondto the largest quantity of carbon dioxiderequired to protect any one area or object.The release systems of the bank and thepipes shall be arranged in such a way that
each protected zone will be floodedindividually. A typical high pressure storagefacility using a number of cylinders is shownin Fig. 5.
Storage temperatures should not exceed, norfall below, the following range unless the
system is designed to operate effectively at
storage temperatures outside this range:
1) Total flooding systems temperaturerange Max 55”C; A4in – 18”C.
2) Local application systems temperaturerange Max 49°C; Min O°C.
External heating or cooling should be usedto keep the temperature located within thedesired range. Where special containercharges are used, the container should beappropriately marked.
Where gas pressure, from pilot cylindersfed through the system discharge manifcld
( that is using back pressure rather than aseparate pilot line ), is used to release theremaining slave cylinders, and the supply
consists of three cylinders, one cylinder shallbe used for such operation. If the supplyconsists of three cylinders or more, there shallbe one pilot cylinder more than the minimumrequired to actuate the system. During thefull discharge acceptance test, the extra pilotcylinder shall be arranged to operate as a slave
cylinder.
13
IS 15528:2004
I
A A
TVENT —
‘w>CHECK
“7VALVES
NOZZLES
I A- DIRECTIONAL VALVES
y\J RELIEF VALVEDISCHARGE PIPEDm INTO OUTSIDE
ATMOSPHERE
L INITIAL Jl- RESERVE JCYLINDERS CYLINDERS
FJci. 5 A TYPICALHIGH-PRESSURESTORAGEFACILITY
An example of cylinder arrangement for three or more
cylinders is to locate a slave cylinder at the farthest
point ( No. 1 position) from the manifold outlet, andtwo or more pilot cylinders in the next two or morepositions ( Nos. 2, 3, and soon), numbering towardthe manifold outlet. Actuation of any remaining pilot
cylinder(s) should provide sufficient pressure in themanifold to actuate the slave cylinders and all other
pressure-actuated devices and interlocks.
Alternate I — When Nz gas pressure from pilotcylinder fed through the system discharge is used torelease the remaining slave cylinders, there shall be
one pilot cylinder of same capacity of slave cylinderminimum required with >10 MPa pressure withpressure regulator suitable to reduce the pressure forthe operation of slave cylinder valve for the multiple
use. Maximum 20 cylinders can permit for discharge.Pressure switch also can provide outlet of pressure
regulator for the alarm indication for pilot cylinderpressure is not available for the activation of the
system. Since cylinder with >10 MPa pressure pilotcylinder can operate number of times, and after everyoperation pilot cylinder need not to send for Nzfilling.
One standby pilot also can propose if the systemhaving large quantity of slave cylinders.
.41ternate 2 — Carbon dioxide master cylinder canalso use for the discharge of slave cylinders in thesystem without using any N~ pilot cylinders. Part
of master cyiinder COZ gas will operate the slavecylinder and balance quantity of CO~ gas fed to the
The carbon dioxide supply shal) be stored incontainers designed to hold carbon dioxide. The
containers shall comply with the following:
a)
b)
c)
d)
e)
f)
Requirements as per IS 8198 ( Part 1 ) and( Part 3 ).
The design shall ensure the temperature ofthe carbon dioxide in the container shall bemaintained between –16°C and –18°C at apressure of approximately 2.0 MPa. Meansshall be provided to indicate continuouslythe quantity of carbon dioxide.
An automatic refrigerating system shallensure that the temperature and pressure of
carbon dioxide are kept within the requiredlimits.
An over-pressure alarm shall be provided
that will sound a local warning atapproximately 10 percent below thepressure at which the pressure relief deviceoperates.
A low-pressure alarm shall also be providedthat will sound a local warning at not lessthan 1.7 MPa.
A contents loss alarm shall also be providedto indicate a loss exceeding 10 percent of
mass. All alarms shall be extended to anormally manned remote monitoring
location.
14
d
h)
j)
k)
m)
n)
P)
The audible warning connected withpressure monitoring shall be independentof the electrical circuit supplying therefrigeration unit.
The cylinder shall have sufficient insulation
to limit the loss of carbon dioxide to not morethan 1.5 percent or 5 kg, whichever is thegreater, up to 6 t charge, not more than
0.8 percent for 6 to 10 tcharge and not morethan 0.5 percent for over 10 tcharge in 24 hin the event of a failure of the refrigeratingsystem at the highest expected ambienttemperature.
Insulation materials shall be protected toavoid mechanical damage.
Containers shall be fitted with pressuregauge(s), safety valve(s) and pressure relief
valves as per IS 14150. Care shall be taken
to ensure that during the filling of thecontainers the temperature of the carbondioxide corresponds to the value necessaryto the proper functioning of the system.
The pressure relief valves shall be mounted
in pairs on a two-way changeover valvearranged to ensure that one relief valve alwaysprovides protection against excessivepressure within the container and the
discharge from the valve shall be piped to
a safe location external to the building. Itshall not be possible for the two-way
changeover valve to isolate both relief valves
at the same time.
Shall have means provided to prevent
containers from being overfilled.
Where the entire contents of a low-pressure container are not to be discharged
at the same time, all control or directionalvalves shall be arranged to close after the
required quantity has been discharged.
8.4 Container Condition
Container shall be thoroughly dried before filling,
especially if the container has been hydrostatically
tested.
NOTES
1 A likely source of contamination would be the presenceof free water in the system container before filling withcarbon dioxide.
2 The requirements of the appropriate authoritiescovering containers could take precedence over therequirements of this Standard, for example, in marineor aviation areas. Accordingly, the appropriate authorityshould be contacted for advice.
3 All high pressure cylinders shall be weighed atleastonce in six months. If at any time a container shows a
IS 15528:2004
loss, in net content of more than 10 percent, it shall berefilled/replaced. Online continuous gas weight monitoringarrangement is recolmmcaded.
9 DISTRIBUTION SYSTEM
9.1 General
In addition to the requirements of IS 15493, thepiping shall withstand the maximum developed
storage pressure, as per Table 7.
Table 7 Typical System Pressures
sl ExamplesNo. of System
Pressure
(1) (2)
i) Low-pressuresyste131s
ii) High-pressuresystems
Nominal MaximumStorage Developed
Pressure Storage PressureWiPa at 55”C, MPa
(3) (4)
2.1 3.1 manifold reliefvalve setting
5.2 15.5
For determining the size of distribution systems,see 6.
9.2 Steel Pipe
Discharge pipes and pipe fittings shall be inaccordance with IS 15493.
Stainless steel pipe and fittings may be used in allapplications, but shall be subject to appropriate design
strength calculations.
9.3 Piping Joints
9.3.1 Joint of’Ferrous Pipes
Jointing of ferrous pipes shall be mechanical, welded,screwed or flanged and comply with IS 10234.
9.4 Dirt Traps
A dirt trap consisting of a tee with a capped nipple,at least 51 mm long, shall be installed at the end ofeach pipe run.
9.5 Safety Devices
9.5.1 Pressure Relief Device
Where there is a possibility of carbon dioxide
entrapment in pipework ( for example, betweencontainer valves and directional valves ), a suitablepressure-relief device shall be fitted as follows:
a) For 2.1 MPa systems, the device shall bedesigned to operate at 3.1 MPa + 5 percent.
b) For 5.2 MPa systems, the device shall bedesigned to operate at 15.0 MPa + 5 percent.
15
1S 15528:2004
Means should be provided for safely depressurizingsuch piping in theevent that the operating pressure
of thedevice has not been attained. Where a valve isfitted for this purpose it shall be monitored.
9.5.2 Discharge Indicator
The discharge indicator shall be as follows:
a) Manually reset, and
b) Provide visible indication that carbon dioxidehas been discharged.
9.6 Pipe and Orifice Size Determination
Pipe sizes and orifice areas shall be selected on the
basis of calculations to deliver the required rate offlow at each nozzle.
The following equation or curves developed from itshall be used to determine the pressure drop in thepipeline:
10-5X 0.8725 D525 YQ2M .
LO.043 19D125Z
OsQm
where
Q,, = flow rate, in kg/rein;
D = inside pipe diameter ( actual ), in mm;
L = equivalent length of pipeline, in m; and
Y and Z = factors depending on storage and linepressure.
NOTES
1 For systems with low-pressure storage, flow shall becalculated on the basis of an average storage pressureof 2.1 MPa absolute during discharge. The discharge ratefor equivalent orifices shall be based on the values givenin Table 9. Design nozzle pressures shall not be lessthan 1.1 MPa,
2 For systems with high-pressure storage, flow shall becalculated on the basis of an average storage pressureof 5.2 Ml>a during discharge for normal 21 “C storage.The discharge rate through equivalent orifices shall bebased on the values given in Table 10. Design nozzlepressure at21 ‘C storage shall be not less than 2.1 MPa.
Figure 6A and Fig. 6B give flow informationfor – 18°C storage temperature on the basis ofabove equation.
9.7.1 The nozzles shall be designed and located in
such a manner that an even distribution of gas willbe achieved throughout the protected space and, atthe same time, the discharge from the nozzles shallnot cause undue splashing of flammable liquids or
creation of dust clouds that might aid spread of fire,cause explosion or otherwise adversely affect thecontents of the protected space. When installed in
duct work spacing and sizing of nozzles is dependentupon the following factors:
a)
b)
c)
d)
Velocity in duct;
Location and effectiveness of dampers;
Possible loading of duct walls withcombustible deposits; and
Duct length and cross-section dimensions.
NOTE — No allowance is needed for inlet and outletduct openings, C02 tire extinguishing system protectingareas where explosive atmospheres could exist shall utilizemetal nozzles and shall be properly grounded. ( Sincedischarge of liquid C02 is known to produce electrostaticcharges which under certain conditions could create aspark. )
9.7.2 For systems protecting quick burningmaterials, the total area of all discharge outlets for
the system or for individual hazards where thesystem is to protect multiple hazards simultaneously,
shall be within 65 to 85 percent of the cylinder
outlet area or of the area of supply pipe, whichever is
smaller. The system protecting materials subject toglow or shouldering ( see hazards in Table 3 ) thetotal area of all discharge outlets shall be withinthe range of 3 to 10 percent of cylinder outlet area,
except that the total area of all discharge outletsshall not exceed 85 percent of the supply pipe area.
9.7.3 Nozzles vary in design and dischargecharacteristics and shall be selected to suit the intended
purpose.
9.7.4 For installations intended for surface fire
protection, the aggregate cross-sectional area ofnozzle outlet shall not exceed 85 percent or be lessthan 35 percent of the aggregate release outlet area
of the system, or minimum cross-sectional area ofthe pipe, as determined from Table 8, whichever issmaller.
9.7.5 For installations intended for deep seatedfire protection, the aggregate cross-sectional area ofnozzle shall not exceed 85 percent of the cross-sectionalarea of the pipe as determined from Table 9, nor be
less than three percent of the aggregate release
outlet area of the system.
17
IS 15528:2004
9.7.6 Nozzles shall be capable of withstandingpressures up to 14 Mpa and shall be of Leaded tinbronze (see IS 318).
9.7.7 Nozzles used in the local application installationsshall be so connected and supported that these maynot be readily put out of adjustment.
9.7.8 Irrespective of the number of orifice or the shape
of the nozzle, it shall be marked, permanently andindelibly, to show its equivalent single orifice diameter.
All nozzles having an equivalent single orifice diameterof 2.38 mm and more shall also be marked with a codenumber as given in Table 8.
9.7.9 The limitations for nozzle spacing andcoverage as well as minimum and maximum distanceabove flammable liquid surfaces ( in depth) shall bedetermined for each type and size of nozzle andchecked and verified by a testing laboratory. Wherethis information is not provided, the limitations
for spacing and location of nozzles shall be governedby the following:
a) Nozzles shall not be spaced more than 1 m
apart. A single row of nozzles may besatisfactory for area, up to 1.25 m width; and
b) One additional row of nozzles shall be
provided for each additional 1.25 m width ofhazard area, or fraction thereof.
9.7.10 Where nozzles are likely to get clogged byforeign materials these shall be provided withfrangible discs which shall automatically rupture
by the pressure of the discharging gas.
10 IDENTIFICATION
Each container shall be identified by being colouredred approximating Signal Red of IS 5 over the whole
of the cylinder.
11 COMMISSIONING AND ACCEPTANCETESTLNG
11.1 Criteria for Acceptance
The completed carbon dioxide system shall becommissioned in accordance with IS 15.493 and the
system’s performance proved by at least one of thefollowing methods:
a)
b)
Subject the system to a full discharge
test, performed in accordance withIS 15493 and the results shall complywith 6.
Where a full discharge test using carbondioxide is not required by the appropriateauthority, the following proc&dure shall
apply:
1) Subject the distribution system to a
Table 8 Orifice Code Numbers and EquivalentOrifice Sizes
NOTE — Formerly, a plus sign following the orificecode number indicated equivalent diameters 0.4 mmgreater than that indicated by the numberingsystem, for example, No. 4 indicated an equivalentdiameter of 3.18 mm ( 4/32 inch) and No. 4+, 3,47 mm( 9/64 inch ).
2)
hydrostatic pressure test of 1.25 timesthe calculated pipework’s maximum
developed storage pressure at 55”C, thenpurge the system to remove the moistureand prove free passage.
Subect the protected area to an enclosureintegrity test.
11.2 Commissioning Certification
When the system is commissioned, the installation
contractor shall issue a test certificate.
18
IS 15528:2004
Table 9 Discharge Rate per 64.5 mmz orEquivalent Orifice Area for Low-Pressure
Storage 2.07 MPa
( Clauses 9.6 and9.7.5 )
S1 No.
(1)
i)
ii)
iii)
iv)
v)
vi)
Orifice PressureMPa
(2)
2.072.001,93
1,861.791.72
1.651.591.52
1.451.381.31
1.241.171.10
1.03
Discharge Ratekg/min/mm2
(3)
2.9702.0411.671
1.4431.2841.165
1.0730.9920.918
0.8510.7920.737
0.6880.6420.600
0.559
11.3 Failure
Where the system fails to comply with eitherIS 15493 or this clause, the fault shall be rectified
and, if necessary, the system retested.
IS No
5:1995
318:1981
7689:1989
8198
(Part l): 1984
(Part 3):1984
Table 10 Discharge Rate per 64.5 mm2 orEquivalent Orifice Area for High-Pressure
Storage 5.17 MPa
( Clause 9.6)
S1 No.
(1)
0
ii)
iii)
iv)
v)
vi)
vii)
viii)
ix)
x)
xi)
xii)
xiii)
xiv)
xv)
xvi)
xvii)
xviii)
xix)
Orifice PressureMPa
(2)
5.17
5.00
4.83
4.65
4.48
4.31
4,14
3,96
3.79
3.62
3,45
3.28
3.10
2.93
2.76
2.59
2.41
2.24
2,07
Title
Colours for ready mixed paintsand enamels (jourth revision )
Specification for leaded tin bronzeingots and castings
Guide for the control ofundesirable static electricity
(first revision )
Code of practice for steel cylindersfor compressed gases:
Atmospheric gases ( firstrevision )
High pressure liquefiable gases
(first revision )
Discharge Ratekg/min/mm2
(3)
3.258
2.706
2.403
2,174
1.995
1.840
1.706
1.590
1.488
1,397
1.309
1.224
1.140
1.063
0.985
0.908
0,830
0.760
0.690
ANNEX A
( Clause 2 )
LIST OF REFERRED INDIAN STANDARDS
IS No Title
10234:1982 Recommendation forline welding
general pipe
14150:1994 Hydraulic fluid power — Pressurerelief valves — Mountingsurfaces
15222:2002 Specification for carbon dioxideas fire extinguishing media for
fire protection
15493:2004 Gaseous fire extinguishingsystems — General requirements
19
Bureau of Indian Standards
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m
of ‘BIS Catalogue’ and ‘Standards : Monthly Additions’.
This Indian Standard has been developed from Doc : No. CED 22 ( 7144 ).
Amendments Issued Since Publication
Amend No. Date of Issue Text Affected
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