Sprinkler 08 Design Densities

8/17/2019 Sprinkler 08 Design Densities

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8. DESIGN DENSITY AND AMAO FOR FULLY HYDRAULICALLYCALCULATED OR PRE-CALCULATED SPRINKLER SYSTEMS.

8.1 The design density and the assumed maximum area of operationfor various types of risks are as specied below and also see Table

2.8.1.18 LIGHT HAZARD: The density of water discharge shall be at least

2.25 lpmm2 over an assumed area of operation covering 8! m2

Not more than six sprinklers shall be installed in a room except ineither a corridor where there is a single line of sprinklers or aconcealed space protected as specied in 12.3.1a!.

8.1.2 ORDINARY HAZARD: The density of water discharge shall be atleast 5 lpmm2 over an assumed area of operation covering "#$m2

8.1." HIGH HAZARD: The density of water discharge for process risksshall be at least 1$ lpmm2 over an assumed area of operationcovering 2#$ m2

TA%LE - 2

MINIMUM DESIGN DENSITY AND AMAO FOR LIGHT& ORDINARY AND

HIGH HAZARD 'PROCESS( RISKS AT ROOFCEILING SPRINKLERS

HAZARD DESIGNDENSITY lpmm2

AMAOm2

L)*+,O)/0H)*+

2.2" ".##1#.##

$%32

8.1.! STORAGE HAZARDS:

8.1.!.1'torage ha(ards are categorised from the nature and type of

storage. )hen the height of storage increases beyond speciedlimits* re ghting is rendered more di+cult. ,n worst cases itmay not be possible to ght the re due to di+culties in reachingthe seat of re and also accessibility to the re ghting sta- isimpaired due to excessive smoke. ,n case of the sprinklers alsothe same di+culties are encountered. 'torage risks can becategorised under ordinary or high depending upon the typeand method of storage of goods within the godown/warehouseblocks

8.1.!.2 The storage occupancies can be regarded as ordinary ha(ard

risks if the height of storage is within the limits for variouscategories as shown below.

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TA%LE 0 "

CATEGORY MAIMUM STORAGEHEIGHT IN METRES

DESIGNDENSITYLPMM2

AMAO M2

I %.## " 3II 3.## " 3III 2.## " 3I3 1.2" " 3

,n other words* goods stored not higher than what is stated in

Table 3 below for the appropriate category 4 not higher than the

eaves height of the roofs 4 within 1 of a at ceiling whicheveris the lowest shall be regarded as O)/0 +00 6,40*7. ,f the above conditions are not met* the risk shall be regarded ashigh ha(ard storage.

8.1.!.",n case of high ha(ard storage risks* the nature of the ha(ard isdetermined by the height of storage* storage aisle width and areaof each storage block. ,n other words* goods stored not higherthan what is stated in Table % below for the appropriate category4 not higher than the eaves height of the roofs 4 within 1 of aat ceiling whichever is the lowest shall be regarded as +)*+

+00 6,40*7.

8.1.5 REUIREMENTS COMMON TO ORDINARY AND HIGHHAZARD STORAGE RISKS

8.1.5.1)herever possible* the deector of the sprinkler tted in theceiling shall be at more than 1." from the goods stored below.4owever* in case of 5ute godowns* no 6ute stock shall reach within2 of the deectors of the sprinkler heads.

8.1.5.2,n case of storage in racks or shelves* if the height of storage ismore than what is specied in Tables 3 and %* intermediate

sprinklers shall be provided for each shelf/rack in addition to theceiling sprinklers and overall design density and 778 shall bemaintained as per the Table 3 or Table %.

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TA%LE 0 !

CATEGORY MAIMUMSTORAGE

HEIGHT INMETRES

DESIGNDENSITY

lpmm

2

AMAO m2

I &." 12."# 2II "." 1".## 2III %." 19."# 3##I3 3." 22."# 3##

8.1.5.",f the top of the storage in the top tiers of the racks or shelves is

within 3 of the roof sprinklers* top tiers need not be protectedby the intermediate sprinklers. 4owever* the other tiers shall

need to be sprinklered.

8.1.5.! The aisle width between the storage stacks shall not be lessthan 2." meters and the maximum area of each storage stack

shall not be more than 1"# m2. ,f these parameters areexceeded* the design density applicable shall be loaded by 2."

:;/2 .

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8.2." HIGH HAZARD:

8.2.".1 The design density* ow rate and pressure re=uirements fordi-erent oor areas for this ha(ard class are as per the Tables "*&* 9 and $ below

TA%LE = 5

P766 7?),+ 15mm 'K8$( 6p)/Bl76 p7-;0l;


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TA%LE -

P766 7?),+ 15mm 'K8$( 6p)/Bl76 p7-;0l;


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8.2.".2 The water supply running pressure at the installation valve >gauge shall not be less than either

a! )here the 778 is not larger than the area protected i.e.

;r A ;f A ;s 4

b! )here the 778 is larger than the area protected i.e.

;red A ;f A ;s

;red B running pressure as specied in tables "* &* 9 and $ asappropriate at a ow rate e=ual to a value as indicated below

;red B 7rea protected/778! C specied ow rate in bar!*

;r B is the running pressure at the design point and ow ratespecied in appropriate tables "*&* 9* and $ in bar!.

;f B is the calculated pipe friction loss between the installationvalve > gauge and the most hydraulically remote design point*in bar!.

;s B is the static pressure di-erence between the highestsprinkler downstream of the design point and the installationvalve D>E gauge* in bar!.

8.2."."9HERE AMAO IS FED %Y MORE THAN ONE DISTRI%UTIONPIPE: The pipe friction loss shall be calculated on the basis thatthe ow rates in the distribution pipes are in proportion to thefraction of the design area fed by each distribution pipe as shownin


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Sprinkler 08 Design Densities