Annexure IV Ndct

8/13/2019 Annexure IV Ndct

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H GENCOMaharashtra State Power GenerationCo. Ltd.

Maharashtra State Power Generation Co. Ltd,

ANNEXURE-IV

TECHNICAL SPECIFICATIONS FOR NATURAL DRAUGHT COOLING TOWER

1.00.00 Intent of the Specification

A single Natural Draught Cooling Tower (NDCT) with dedicated Coolingater !asin" #utlet Channel" sludge re$o%al su$& and %al%e &it" etc.shall 'e &ro%ided or the 00 M *nit.

This s&eciication co%ers the re+uire$ents o design and construction onatural draught reinorced concrete h,&er'olic cooling tower. Thissection o 'idding docu$ent deals with the technical s&eciications orthe design and &re&aration o detailed wor-ing drawings and gettingthe$ a&&ro%ed ', the #wner and the ci%il construction wor-s.

The &ro%isions o this technical s&eciication are general in nature andco%er 'road as&ects. Technical s&eciication outlines the $ini$u$re+uire$ents. owe%er" it would 'e the a'solute res&onsi'ilit, o the'idder to collect" inter&ret" anal,/e all necessar, inor$ation data orthe successul design and construction o the cooling tower. Structuralsaet, and successul o&eration o the tower shall 'e the totalres&onsi'ilit, o the 'idder notwithstanding the a&&ro%al o the #wner.

.00.00 Scope of Wo!

The sco&e o this wor- shall consist o" 'ut not li$ited to" the design and

construction o reinorced concrete dou'le cur%ature h,&er'olic shell"ra-er colu$ns" ring 'ea$s" oundations including &iling wor-(%erticalra-er &iles)" cold water 'asin with &artition walls" hot waterducts" drain su$&s" e2ternal drain cha$'er with associated &i&e wor-"cold water channels with sluice gates and re$o%a'le screens ass&eciied elsewhere" hoists 3 $onorails" &ri$ar, and secondar, hotwater distri'ution troughs" ill su&&ort s,ste$s including colu$ns 3'ea$s" drit eli$inators (i re+uired)" testing o cold water 'asin orwater tightness" e2ternal stairs" cage ladders" handling acilities at towerto& with wal-wa, &lator$ and C channel" &lator$s" wal-wa,s ass&eciied or re+uired or o&eration and $aintenance" access doors" MShandrails" steel ittings" i2tures" inserts including a'rication" gal%ani/ing

and erection o associated steel wor- and other che$icals on theco$&leted structures etc. all co$&lete as &er unctional re+uire$entsand as &er directions o #wner.

The sco&e o wor- under this s&eciication shall include &ro%idingengineering design and drawings" all la'our" su&er%ision" $aterials"shuttering and scaolding" construction e+ui&$ents including tower

Khaperkheda TPS Expansion Project

1 x 500 MW, Balance of Plant Package

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cranes" hoists" 'atching &lants etc. tools and &lant" su&&l, andtrans&ortation o all incidental ite$s not shown or s&eciied 'utreasona'l, i$&lied or successul co$&letion o the wor-. The nature othe wor- shall generall, in%ol%e oundation&iling" e2ca%ation"

dewatering" shoring and strutting" 'ac-illing around undergroundstructures and &linth illing" sand illing" dis&osal o sur&lus soil outside&lant 'oundar," concreting o grade as s&eciied" or$wor- includingauto$atic cli$' or$" laser 'ea$ instru$ents" a'rication" gal%ani/ingand erection o steel structures and inserts" inishing anchor 'olts" 5CCsu$&duct" la,ing and testing o hot water &i&e line" water &rooing"&ro%iding P6C water sto&s and 7oint ilters" drainage and other ancillar,ite$s connected with cooling towers as a&&ro%ed. The surace&rotection that would include all inner ace o h,&er'olic shell" ra-ercolu$n aces" inner aces o cold water 'asin" ill su&&ort structures" hotwater distri'ution ducts 3 channels" cold water channels etc. This list isindicati%e and the sco&e shall also include the &re&aration and su&&l, o

all wor-ing drawings re+uired or this wor-.

8.00.00 De"i#n Paa$ete"

The design &ara$eters or the NDCT shall 'e as ollows9

:uantit, 9 #neT,&e o Tower 9 Counter low with P6C il$

illater low rate 9 ;8"00 $8hr Cooling 5ange 9 10.00.00 De"i#n Con"i%eation"

The cooling tower shall 'e designed or continuous o&eration. The hotwater distri'ution s,ste$ shall 'e designed to ensure e+ual distri'utiono heat load and low all o%er the ill area. oodti$'er $aterial shallnot 'e used in an, &art o the cooling tower.

.00.00 &ateia'" of Con"t(ction

Cooling tower 'asin 9 5CCCooling tower shell 9 5CC@nternal su&&orting structure"stair cases" etc. 9 5CCLou%ers !ales 9 5CC



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il$ ill 9 P6Cill su&&orts 9 5CCNo//les 9 Pol,&ro&,leneDrit eli$inators (!lade t,&e) 9 P6C

ot water inlet &i&es 9 Mild Steel to @S 0;ot water distri'ution s,ste$ 9 ACDistri'ution trough 9 5CCSluice gates 9 MS Gal%ani/edSide guides and $ountings 9 SS 81;Miscellaneous steel structures 9 MS Gal%ani/edScreens 9 SSB80>

;.00.00 Coo'in# To)e St(ct(e

;.01.00 The cooling tower shell shall 'e h,&er'olic &ara'oloid. The shell o thecooling tower shall 'e su&&orted ', a set o diagonal colu$ns" which

shall 'e su&&orted ', &iles and a &eri&heral &ile ca& or oundation asthe case $a, 'e.

;.0.00 ot water inlet shall 'e through a &air o MS &i&es suita'l, &rotected.The &i&es shall ha%e 'utterl, %al%es and also re+uired nu$'ers other$owel with 5TD" &ressure and low $easuring instru$ents. !lowBdown shall 'e ta&&ed ro$ the &i&ing.

;.08.00 Se&arate &i&ing or hot water inlet ro$ AC circuit into the NDCT shall'e &ro%ided ', the side o hot water inlet &i&ing or CC circuit. The

AC &i&ing shall also ha%e 'utterl, %al%es. Painting and &rotection ohot water &i&ing shall 'e done as &er rele%ant @S codes.

;.0>.00 To control the h,draulic orces at the change o align$ent o the hotwater () inlet &i&e" a 5CC thrust 'loc- shall 'e &ro%ided at groundle%el near the cooling tower along with suita'le other su&&orts.

;.0.00 The hot water distri'ution shall 'e ', 5CC $ain and secondar, ductswhich carr, the lateral distri'ution &i&es itted with no//les or unior$distri'ution through the ill.

;.0;.00 The concrete $ain distri'ution ducts shall 'e accessi'le and are to 'e&ro%ided with nonBcorroding" &ressureBsealed ins&ection o&enings.Cleaning and sludgeBre$o%al o&enings are to 'e included on each run

at the end o the duct in the $ain distri'utor.

;.0.00 The distri'ution arrange$ent shall 'e su&&orted inde&endent o theshell ', internal colu$ns su&&orted on the loor o the cold water 'asin.

;.0.00 The &roile o the drit eli$inators is to 'e selected to ensure a$a2i$u$ degree o &reci&itation and a $ini$u$ o air &ressure loss.



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;.0=.00 Access to the hot water distri'ution &lator$ and urther access to theshell to& should 'e &ro%ided with two Gal%ani/ed Steel cage ladders.

;.10.00 The $aterial used or access acilities including steel co$&onents orste&s" ladders" &lator$s" catwal-s" railings" doors" 'ase ra$es"$ountings" etc $ust 'e gal%ani/ed and resistant to corrosion.

;.11.00 All 'olted connections and attach$ents to concrete $ust 'e $ade outo suita'le stainless steel $aterial.

.00.00 The 'asin shall 'e designed or a water de&th" as &er the GA Drawing"with a ree 'oard o at least 0.8 $ a'o%e $a2i$u$ water le%el. Thecooling tower 'asin shall 'e di%ided into two e+ual &arts ', watertight5CC &artition or the cleaning and $aintenance o one hal while theother hal is in ser%ice. Arrange$ents or water drainage shall also 'e

&ro%ided. Suita'le o%erlow arrange$ent" to $aintain the $a2i$u$water le%el at 800 $$ 'elow the sill in 'oth the co$&art$ents" shall 'e&ro%ided.

.00.00 The cold water ro$ the 'asin shall 'e ta-en out through an o&eningconnected to the $ain C closed Channelduct" which in turn leads to aoreB'a, o the C su$&. The cold water ro$ the 'asin shall low ',gra%it, to o&en a&&roach channel leading to the oreB'a,. The coldwater channel shall 'e &ro%ided with a sluice gate. Suita'le handlingarrange$ents with a $onorail and a chainBo&erated hoist with atra%eling trolle, shall 'e &ro%ided or handling o the sluice gate. @n ronto the outlet structure" &ro%ision shall 'e $ade or deBsludging acilities

so that sedi$ents can 'e withdrawn ro$ the 'asin. @n order to cleanthe cooling tower 'asin" sludge su$&s are to 'e &ro%ided along its&eri$eter" ro$ where the sludge can 'e &u$&ed out.

Two sludge &u$&s shall 'e &ro%ided or the re$o%al o sludge ro$ theNDCT to drain su$&s. All the drains shall 'e ter$inated in the 4TP.

=.00.00 Fi'' S(ppotin# Aan#e$ent

The su&&orting o the ill is to 'e achie%ed ', a series o 5CC colu$nsarranged in suita'le grid s&acing and 5CC 'ea$s in orthogonaldirections. Loads ro$ ills" hot water ducts" &i&es including water load"

wall 'loc-s" etc. shall 'e considered or colu$nB'ea$ design. To ta-ecare o hori/ontal loads due to seis$ic and thrust ro$ hot waterheader" a suita'le s,ste$ o %ertical 'racings is to 'e designed and&ro%ided in either direction.

10.00.00 Concrete" which is i$&er$ea'le to water" is to 'e used or allco$&onents" including reinorced concrete co$&onents. The



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co$&osition o the concrete and the ce$ent are to 'e chosende&ending on the che$ical anal,sis o the cooling tower watercoolingtower $a-eBu& water.

11.00.00 A*iation O+"t(ction Li#ht"

@n accordance with @CA# regulations" a%iation warning lights are to 'einstalled along the &eri$eter o the NDCT o&ening. #&erating andreser%e a%iation warning lights are to 'e &ositioned ne2t to each other.The, are to 'e connected to co$&letel, se&arate &ower circuits and to'e $onitored ', rela,s. Suita'le &hotoBelectric sensors" alar$ andannunciation s,ste$s" etc. shall also 'e &ro%ided along with there+uired au2iliaries or co$&leting the s,ste$ in all res&ects.

1.00.00 Eathin# an% Li#htnin# Potection

A suita'le s,ste$ o earthing and lightning &rotection" includingre+uired hoo-Bu& with the &lant grids,ste$" etc. shall 'e &ro%idedco$&letel,. All the electrical re+uire$ents" including ca'les shall 'e as&er &lant electrical s&eciications.

18.00.00 G(aantee% Patic('a"

The contractor shall guarantee the ollowing &ara$eters9

Co'% )ate te$peat(e

At the design &oint o the cooling tower" the cold water te$&erature

guaranteed ', the Contractor in accordance with the &eror$ance cur%e(cooling tower characteristic cur%e) shall 'e achie%ed. The unda$ental&ara$eter or the design %alue o the cold water te$&erature duringacce&tance $easure$ent shall 'e that $easured at the cooling tower'asin outlet.

Dift 'o""e"

At the design &oint" the total water $ass low entrained in the air shallnot e2ceed 0.01? o the $ass o water circulating. @n case the driteli$inator &ac-ing is to 'e used or achie%ing the s&eciied drit lossthen" the sa$e shall 'e &ro%ided ', the 'idder.

@ drit eli$inators are &ro%ided then" the drit shall 'e $easured at theto& o the drit eli$inators.

1>.00.00 &ateia' e"i"tance



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All $aterials (including 'uilding $aterials) are to 'e chosen and gearedto each other such that no da$age will 'e occurred as a result oo&erational e2&osure to cooling water.

1.00.00 Latest %ersions o the ollowing codes and standards shall 'e used orconducting the &eror$ance tests9

D@N 1=> E 6D@ 9 Acce&tance test code or water coolingtowers

!S9 >> 9 S&eciication or ater Cooling towers!S9 10> 9 Methods or the $easure$ent o luid low

in &i&es!S9 8>8 9 Measure$ent o electrical &ower and

energ, in acce&tance testingASM4 E 1=. 9 Su&&le$ents on @nstru$ents andA&&aratus

1;.00.00 Contractor shall arrange or all the test instru$entation re+uired orconducting the &eror$ance guarantee tests. All instru$ents used ortesting shall 'e cali'rated 'eore the tests as &er the rele%ant codes.Should the acce&tance tests not &roduce the guaranteed %alues" theContractor shall 'e granted the right to $a-e i$&ro%e$ents. There&eated acce&tance $easure$ents shall then 'e carried out at theContractorFs e2&ense.

1.00.00 &ateia'"

All $aterials including ce$ent" reinorce$ent steel 3 structural steel

re+uired under this 'id shall 'e &ro%ided ', the 'idder. No $aterialsshall 'e issued ', the #wner.

1.00.00 La,o(t an% Le*e'"

The la,out i2ing the location and le%els o all structures shall 'e $ade', the 'idder (at his own cost) w.r.t. &lantFs grids and 'ench $ar-sgi%en ', the #wner. The !idder shall e2tend all hel& in &ro%iding theinstru$ents" $aterials and $en to the #wner or chec-ing thecorrectness o the la,out and le%els. owe%er" the 'idder shall 'e solel,res&onsi'le or correctness o la,out and le%els and #wnerFs a&&ro%al inno wa, shall relie%e the 'idder o his res&onsi'ilit, towards correctness

o la,out and le%els.

1=.00.00 Appo*a' of De"i#n an% Da)in#"

The 'idder shall su'$it detailed ther$al design 'asis and calculationsin the or$ o a re&ort to $eet !S9 >> re+uire$ents. The#wnerConsultant shall chec- and a&&ro%e the ther$al design. #nce



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the ther$al design is a&&ro%ed" the 'idder shall su'$it detailedanal,sis 3 design calculations or the cooling tower structures includingdesign assu$&tions along with arrange$ent drawings or the a&&ro%alo the #wnerConsultant. The theoretical 'ac-ground utili/ed or

de%elo&ing the co$&uter &rogra$$es shall 'e $ade a%aila'le to the#wner. This will 'e gi%en ', the 'idder 'eore a&&ro%al o designs. #neset o anal,sis 3 design calculationdrawings dul, a&&ro%ed $ar-edwith co$$ents ', the #wner shall 'e returned to the 'idder.

Ater recei&t o a&&ro%al ro$ the #wner the 'idder shall su'$it co&ieso inal detailed constructiona'rication drawings as &er Distri'utionSchedule or the a&&ro%al o the #wners. #ne set o drawings shall 'ereturned dul, a&&ro%ed which will 'eco$e the 'asis or ta-ing u&construction. The 'idder shall also urnish to the #wner one good+ualit, &er$anent negati%e (il$ t,&e) o each o the inal a&&ro%eddrawings. Additionall," all drawings shall 'e &re&ared in A*T#CAD and

CDs to 'e su'$itted to the #wner or record. The a&&ro%al o the#wner shall not relie%e the 'idder ro$ the res&onsi'ilit, o ade+uac, othe design and correctness o the drawing.

0.00.00 Genea' Re(ie$ent"

All oundations shall 'e designed in accordance with &ro%isions orele%ant &arts o the latest re%isions o @ndian Standards and accordingto geotechnical in%estigation re&ort" a&&ro%ed ', #wner.

1.00.00 Genea' De"i#n Citeia

Loading

The ollowing loads shall 'e considered or the design o cooling towers9

a) Dead loads') ind loadsc) 4arth+ua-e orcesd) Loads due to te$&erature and shrin-age eects. Te$&eratureeects due to solar radiation shall also 'e considered.e) Construction load) oundation settle$ent etc.g) An, other load li-el, to co$e on cooling tower.

Dea% Loa%

or assessing the sel weight o the structure" the s&eciic weight o theconcrete shall 'e ta-en as 00 -g$8. All other dead loads shall 'eassessed in accordance with rele%ant codal &ro%ision. Dead load shallinclude the sel weight o structure" weight o ill $aterial" weight due to



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Model test and theoretical $ethods. *nder the theoretical $ethod" thecircu$erential net wind &ressure distri'ution and wind &ressurecoeicient (&1) or the tower shell (without $eridional ri's) shall 'eo'tained ro$ the Criteria or structural design o 5einorced concrete

Nature Drat Cooling Towers @S9110>B1=. The a'o%e circu$erentialwind &ressure coeicient (&1) shall 'e increased ', $ulti&l,ing it ',1.>8 to account or tur'ulence in the incident wind and loadintensiication due to tur'ulence induced ', the ad7acent cooling toweror the other structures o signiicant di$ensions. Thereore" the actualdesign circu$erential net wind &ressure coeicient (&) shall 'eco$&uted as &H1.>8(&1)" where (&1) is the wind &ressure coeicient as&er @S9 110>B1=.

This design net &ressure coeicient (&) and the distri'ution along thecircu$erence o tower shall 'e used at all heights o the tower. Thea'o%e design net &ressure coeicient (&) shall include the eect o

internal suction.

@n order to co$&ute the +uasiBstatic design wind &ressure at a gi%enheight along the circu$erence o the tower" the net design &ressurecoeicient (&) shall 'e $ulti&lied ', the wind &ressure acting at thatheight IP(/)J. or details" reerence shall 'e $ade to Criteria or ind5esistant Design o Structures and 4+ui&$entsK &laced under Pro7ectData and as gi%en 'elow.

The wind &ressure at a gi%en height IP(/)J shall 'e co$&uted as &er thesti&ulations o @S9 (Part 8)B1=. or co$&uting the design wind&ressure at a gi%en height the 'asic wind s&eed (6') shall 'e ta-en as

6'H0 $sec at 10.0 $eters height a'o%e $ean ground le%el. orco$&uting design wind s&eed (6/) at a height /" the ris- coBeicient1H1.1 shall 'e considered. or coeicient " Terrain categor, andclass CF as &er ta'le o @S9 (PartB8) E 1= shall 'e considered.Coeicient 8 shall 'e deter$ined ', ta-ing into account o the&resence o hilloc- near', the &lant site and other eatures o thestation 3 to&ogra&h,. The wind direction or design &ur&oses shall 'ethe one which would induce the worst load conditions. owe%er"coeicient 8 shall 'e less than one under an, circu$stances. Thewind &ressure at a gi%en height shall 'e co$&uted theoreticall, inaccordance to the @S Codal &osition gi%en as under9

P/ H 0.; 6/

N$$

The 'idder shall also co$&ute the wind &ressure (&/) along the winddirection ', Gust actor (G) or Gust eecti%e actor $ethod (G4).Method or esti$ating the wind load on the tower and other ele$ents"shall 'e 'ased on @S9 (PartB8)B1=. hile calculating the gustactor" the ter$ 'F shall 'e ta-en as the dia$eter o the throat in ig. 10o @S9 (PartB8)B1=.



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te$&erature %ariation ro$ 1oC to 0oC. owe%er" the detailed anal,siso actual ther$al gradient ', considering te$&eratures inside the towerand e2ternal a$'ient te$&eratures shall 'e carried out urnishingdetailed reerences and 7ustiication or the sa$e.

The shell shall also 'e chec-ed or ther$al stresses arising due to&artial o&eration o the tower in case the o&erational &hiloso&h, sode$ands. The anal,sis or the stresses resulting ro$ nonBa2iBs,$$etric te$&erature loading shall 'e carried out. @n such nonBs,$$etric te$&erature loading" the calculation shall 'e 'ased u&on theo&erating s&eciication. !esides" the shell shall also 'e designed or onesided solar radiation eect. Ne%ertheless an eecti%e te$&eraturedierence o at least 0C across the shell thic-ness constant o%er theheight and ollow a sine unctions along hal the circu$erence shall 'econsidered.

4ntire anal,sis and designs ado&ted shall 'e ull, su&&orted withauthenticated literatures docu$ents along with rele%ant reerenceswhere the sa$e has 'een successull, i$&le$ented.

Con"t(ctiona' Loa%in#"

The $ethod o construction and the t,&e o or$wor- to 'e used shall'e decided ', the 'idder in ad%ance and should 'e enclosed in the 'idssu'$itted. Construction loadings that $a, occur during e2ecution owor- shall 'e considered in the design o the cooling tower structure.actors causing te$&orar, loading $a, include the ollowing de&endingu&on the $ethod o construction.

a) !arrowing o concrete') Scaolding and or$wor-c) Loads &roduced ', anchoring de%ices o cli$'ing scaolds.d) oist i2ingse) Storage o $aterials on scaolding') Te$&orar, accessc) Tower crane i2ingsd) or-s te$&oraril, o$itted or access &ur&oses.

An, other load such as oundation settle$ent" etc.

All loads li-el, to act on cooling tower 'ut not s&eciied herein shall also'e considered or the design o cooling tower structures.

@n case dierent degrees o su'soil stiness e2ist" eect o the sa$eshall 'e ta-en into account. @n such a case" or co$&uting settle$ents"load distri'uting ca&acit, o the shell $a, 'e considered. Dierential



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settle$ent 'etween ad7acent sections o oundation shall 'e consideredunder $ost una%oura'le load co$'ination.

1.00.00 Loa% Co$+ination"

ollowing $ini$u$ load co$'inations shall 'e considered or thedesign o cooling towers structures.

a) DL L SL') DL Se Lc) DL TLd) DL L TL SLe) DL Se L TL SL) 1.0 DL 1. L

here DL H Dead Load

L H ind LoadSL H Settle$ent LoadSe L H Seis$ic LoadTL H Ther$al Load

@n addition to a'o%e" construction loads shall 'e dul, accounted or.*nder TL %arious t,&es o ther$al loads" as descri'ed a'o%e" shall 'econsidered se&aratel,. !esides a'o%e load co$'ination" other loadco$'inations as &er rele%ant @S codes shall also 'e ollowed.

.00.00 Pe$i""i+'e Ste""e"

or load co$'ination (a) to (e) the stresses in concrete andreinorce$ent shall 'e restricted as &er li$it state $ethod o @S9 >;with ser%icea'ilit, criteria o crac- width li$ited to 0.8$$.

or the load case () the shell o cooling towers shall 'e designed ',li$it state $ethod as &er @S9 >;. The stress in the reinorce$ent steelshall not e2ceed ? o the s&eciic characteristic strength oreinorce$ent steel and the co$&ressi%e stress in the concrete shall note2ceed >? o the s&eciied da,s cu'e strength o the concrete as&er @S9>;.

@n the design o the cooling tower shell" colu$n" &ile ca&s" &edestals"

ring 'ea$s etc. no increase in the strength with the age o the concreteshall 'e &er$itted. The age actor e+ual to >.0 shall 'e considered.

Per$issi'le stress or steel structures shall 'e as &er @S9 00 (latest)'ased on wor-ing stresses.

8.00.00 To)e De"i#n Con"i%eation



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i) General

The co$&lete cooling tower" including the shell" colu$ns" ring

'ea$ and oundation" shall 'e structurall, anal,/ed using a&ro%en inite ele$ent $odeling techni+ue or an a&&ro%edalternati%e $ethod including %alidation o sotware used oranal,sis. or elastic anal,sis" concrete $a, 'e assu$ed to 'euncrac-ed" ho$ogenous and isotro&ic. The design geo$etric&roile" thic-ness %ariation and su&&ort conditions o shell shall'e considered in the structural anal,sis.

5egardless o anal,sis $ethod ado&ted" the e+uili'riu$ chec-so internal orces and e2ternal loads shall 'e &eror$ed.

Anal,sis 'ased on a recogni/ed 'ending theor, o the elastic

shells shall 'e ado&ted or the design o the tower andsu&&orting structures.

Geo$etric i$&erections" i e2ceed the &er$issi'le li$it" then theanal,sis o shell shall ta-e into account o such i$&erectionsand resu'$itted or #wnerFs a&&ro%al.

!oundar, conditions shall 'e realistic and 'ased on actualconiguration. The $agnitude o the calculated dis&lace$entsshould 'e within li$its o the a&&lied theor,.

A detailed d,na$ic anal,sis shall 'e carried out or co$&lete

tower or seis$ic orces ', res&onse s&ectru$ $ethod. Coolingtower shall also 'e designed or cross wind oscillations (windinduced %i'ration) i the unda$ental natural re+uenc, o thetower is less than or e+ual to 1 /. re+uenc, calculation orree %i'ration anal,sis shall also 'e urnished ', 'idder duringdetailed engineering.

@@) Si/e and Sha&e

The 'ase dia$eter" air inta-e o&ening height" tower height and throatdia$eter shall 'e deter$ined ', ther$al design consideration ', the'idder and su'$itted to #wner or a&&ro%al.

As the range o &ossi'le h,&er'olic shell sha&es is ininite" the sa$eshall generall, conor$ to the ollowing $a7or &ro&ortions" which ha%e'een e2tensi%el, ado&ted in cooling tower constructions.

D H 1. to 1.here is the total tower height a'o%e 'asin sill le%el



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' H 0. to 0.' is the %ertical distance ro$ the throat to 'asin sill le%el and DF is the'ase dia$eter at 'asin sill le%el.

owe%er" other &ro%en &roiles $a, 'e &er$itted su'7ect to a&&ro%alro$ the #wner. !idders shall su'$it along with the oer co$&letedetails o the &roile" in case the &roile is not within the li$its stateda'o%e" and the na$es o the sites where such shell &roiles ha%e 'eensuccessull, constructed. Notwithstanding what is stated a'o%e" the#wner reser%es the right to acce&t re7ect the shell &roile.

@@@) Tower Shell !oundar, Conditions

A. Shell Anal,sis and Design

The ollowing 'oundar, conditions shall 'e assu$ed or thedesign o cooling tower shell9

a) At *&&er 4dge

The to& edge o the shell shall 'e graduall, thic-ened to or$ aring 'ea$ to guard against &ossi'le insta'ilit, o the to& o theshell due to high %elocit, wind gusts. To& edge shall 'econsidered as a ree edge in the anal,sis.

') At Lower 4dge

The lower edge o the shell shall 'e thic-ened to or$ a lowerring 'ea$. The thic-ness transition ro$ shell to lower ring 'ea$shall 'e s$ooth and shall 'e considered as an integral &art othe shell. The lower 'oundar, o the shell shall 'e considered aselasticall, su&&orted ', discrete colu$ns.

The inluence o 'oth su&&ort structure le2i'ilit, and oundationsettle$ent shall 'e considered in the anal,sis and design ocooling tower shell. The shell anal,sis should include ollowinginor$ation at 10o&lan angle and o not $ore than 0.0 o theshell height.

i) Meridional and circu$erential direct stress resultantsand the tangential shear stress resultants.ii) Meridional and circu$erential 'ending $o$ents.iii) Dis&lace$ents nor$al to the shell $idBsurace.

!. !uc-ling o Tower Shells



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Critical d,na$ic &ressure (wind &ressure) at 'uc-ling shall 'ealculated ro$ !S9 >> PartB>91==;.

The shell 'uc-ling shall 'e chec-ed using the design d,na$ic

wind &ressure and other rele%ant loads acting on the tower. Theactor o saet, against 'uc-ling shall 'e not less than or theco$&leted tower as well as while under construction.

!esides a'o%e" a 'uc-ling anal,sis with wind orces should 'e$ade using the theoretical tower geo$etr, and 'oundar,conditions" including the inluence o dead weight" ', the $ethodo 'uc-ling stress state (!SS) a&&roach in accordance with the&ro%isions o 6G!.

The 'uc-ling saet, actor shall 'e at least .0 or loadco$'inations o dead load wind load.

hen i$&erections in the shell geo$etr, are larger thans&eciied tolerances" the anal,sis should 'e rechec-ed toaccount or such i$&erections and ensure that the desired'uc-ling ca&acit, re$ains.

C. #&ening in Shells

#&ening through the shells should 'e a%oided as ar as&ossi'le. The, should 'e o s$allest re+uired di$ensions andshall 'e sha&ed such that stress concentration is $ini$i/ed atthe 'oundar, o the o&ening. Should thic-ening o the edges 'e

necessar," it shall 'e s$oothl, te$&ered 'ac- to the shellthic-ness.

#&enings shall 'e &ro%ided with additional edge reinorce$ento a $ini$u$ cross sectional area at each edge e+ual to ? othe reinorce$ent interce&ted ', the o&enings in the direction&arallel to the edges. @n addition diagonal reinorce$ent shall 'e&ro%ided at each corner as close as &ossi'le. The total crossBsectional area in c$ o this reinorce$ent shall 'e 0.d" at eachcorner wheredF is the shell thic-ness in c$.

No hori/ontal thrust due to the inlet &i&ing shall 'e trans$itted to

the shell.

D. Mini$u$ Thic-ness o Shell

The $ini$u$ thic-ness o the shell shall not 'e less than 00$$.



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(latest). All other actors including load intensiicationactors shall 'e as s&eciied else where in theses&eciications.

c) Shell 'uc-ling and strength shall 'e chec-ed as &erclauseB' a'o%e without considering the eect o ri's.

d) All other sti&ulations as s&eciied in these s&eciicationsshall 'e $et with.

e) !idder shall urnish an authori/ed 4nglish translation othe 6G!B!T5 *LT*5M4 G45MANSP4C@@CAT@#NS (Latest) during detailed engineeringstage.

@6) 5a-er Colu$ns

@nclination o the colu$n shall closel, $atch the $eridional slo&e at theshell so that the load transer to oundation ta-es &lace through&redo$inantl, a2ial orce in colu$ns. 5a-er colu$ns shall 'e designedor the $ost critical orces transerred to an indi%idual ra-e colu$n ro$su&erstructure considering %arious load co$'inations as s&eciied inthis docu$ent.

or selecting eecti%e length o the ra-er colu$ns" ollowing restraintsshall 'e considered9

a) @n case colu$ns restrained at 'oth the ends" the eecti%e length

shall 'e 0. and 0.; ti$es the length o the colu$n radiall, andtangentiall, res&ecti%el,.

') @n case colu$ns are restrained at one end onl," the eecti%elength o colu$ns shall 'e 0.= and 0. ti$e the length ocolu$ns radiall, and tangentiall, res&ecti%el,.

c) The colu$ns shall 'e designed 'ased on wor-ing stress $ethode2ce&t or the orces ro$ DL 1. L which shall 'e designedas &er li$it state o strength $ethod o @S9>;.

6) Crac- idth Control

*nder wor-ing stress $ethod the $a2i$u$ crac- width o tower shell"lintels" ra-er colu$ns" cold water 'asin and ill su&&ort structure shall 'econtrolled u& to 0.8 $$ on 'asis o or$ulas as &er @S9>; and rele%ant!ritish codes.



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ill su&&ort structures and Drit 4li$inators shall 'e designed as &er theload co$'inations s&eciied in this docu$ent. A&&ro&riate Li%e Loadsand i$&osed loads shall also 'e considered in addition. The designshall conir$ to li$it state $ethod as &er @S9 >;. or ill su&&ort

structure" the design shall 'e done considering the weight o ills" allingwater" &luggingscaling load and the li%e load due to the $aintenanceacti%ities.

6@) Prestressed Concrete Me$'ers

Design construction and wor-$anshi& o &restressed concrete"$e$'ers shall 'e in accordance with @S9 18>8 (Latest re%ision). Steelwire or &restressing shall conor$ to @S9 1 (Part 1) (latest edition) or@S9 ;008 (latest edition). Crac- width control shall 'e li$ited to 0.1 $$.

Particular attention shall 'e &aid to achie%e an eecti%e 'ond o the

wires in &retensioned concrete units. or this &ur&ose" indented wireshall 'e used. ires shall 'e corrosion resistant ($arine grade) orshould ha%e coating s,ste$ it or seawater dut, condition.

6@@) Li+uid 5etaining Structures

a) The cold water 'asin including sludge &its" cold water channels"shall 'e designed as &er @S9>; (latest) with crac- width controlo 0.1 $$ or outer ace o the wall and inside ace o the wallshall 'e designed as &er @S 880.

The structures shall 'e designed or the ollowing conditions9

i. ater illed inside u& to $a2i$u$ le%el and no earth outside.ii. 4arth &ressure with surcharge load o . t$" as a&&lica'le"

and withwithout ground water ta'le at inal graded ground le%eloutside and no water inside.

') The 'asin and associated structures shall 'e chec-ed against u&lit or'asin e$&t, condition. Sta'ilit, shall 'e chec-ed during constructionstage as well as $aintenance stage. The actor o saet, shall 'e as &er@S9 880.

c) Loads during construction" erection and $aintenance stage shall also'e considered.

d) Te$&erature luctuations ro$ o&eration shall 'e o'tained ro$ thedesign data. ot water te$&erature inside and cold air te$&eratureoutside shall 'e considered.

e) !asin loor sla' shall 'e designed to rest on &iles or rat$at oundationincluding illB&ac- su&&ort structures. The stiness o the su'soil shall'e ta-en into account. The ounding le%el o the rat$at shall 'e eitheron %irgin ground le%el or shall 'e &laced at higher le%el onl, ater



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scoo&ing out illed u& soil u& to %irgin ground and then illing 'ac- withwell co$&acted sand (0? o relati%e densit,) u& to the ounding le%elo the rat$at. The 'idder shall ascertain the sae 'earing ca&acit, othe stratu$ at the ounding le%el and $a, ado&t the sa$e su'7ect to

#wnerFs a&&ro%al.) Mini$u$ thic-ness o 'asin sla' shall 'e 800 $$ with $ini$u$

reinorce$ent 0.8? o gross sectional area in 'oth the directions.5einorce$ent shall 'e &laced in two la,ers" to& and 'otto$ surace.The eect o &ro%ision o la& %al%es&ressure release %al%es shall not'e considered in the design o C 'asin. @n the s&ace underneath the'asin loor sla' a la,er o at least 100 $$ thic- PCC o $i2 1989; shall'e &ro%ided.

g) All reinorce$ents used shall 'e corrosion resistant steel o $arinegrade.

6@@@) ater Distri'ution S,ste$

The structural design o the water distri'ution s,ste$ shall consider theworst co$'ination o ollowing loads9

i) Sel weight" other i$&osed loads and li%e load.ii) ,draulic &ressures during nor$al o&erations including &ressure

surges.iii) ,draulic &ressure due to $alBo&eration o the tower or su&&l,

&u$&s.

The water distri'ution s,ste$ shall 'e &ro%ided with ade+uate &ressuresurge relie acilities to &re%ent &ressure loading in e2cess o %alues

used in the design. @ such acilities are not &ro%ided" a urther increasein loading shall 'e considered in the design. or the structural designthe &ressure le%el to 'e considered shall not 'e less than 1. ti$es thedesign &ressure.

The design o water distri'ution s,ste$ and its su&&orts shall 'eca&a'le o acco$$odating all ther$al stresses and $o%e$ents due tochanges in inlet water te$&erature and a$'ient te$&erature.

The &ossi'ilit, o %i'rations 'eing i$&osed on the distri'ution s,ste$shall 'e in%estigated in the design. Seis$ic loading on the waterdistri'ution s,ste$ shall also 'e ta-en into account.

The design shall 'e carried out 'ased on uncrac-ed section as &er @S9880 under nor$al o&erating conditions. Strength chec- or worstloading including $alunctioning shall 'e carried out with stressli$itations as &er @S9 880. The construction shall 'e co$&letel, watertight without the use o illets" sealing co$&ounds etc. The $ethod o



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construction shall 'e such so as to a%oid e2cessi%e rise in te$&eratureo concrete due to release o heat o h,dration.

@O) Plator$s" al-wa,s" Stairwa,s" Staircases" @nternal Grillage etc.

These shall 'e designed as &er wor-ing stress $ethod @S9 >;B1=and @S9 00 (Latest). The crac- width in all 5CC structures shall 'eli$ited to 0.1 $$. A $ini$u$ li%e load o >00 -+s+$ shall 'econsidered or the design o all &lator$s" wal-wa,s" staircases etc. inaddition to their own weight.

O) Steel Structures

These structures shall 'e designed" a'ricated and erected as &er @S900 (latest re%ision) and other rele%ant @ndian Standard codes orstructural steel wor-. All steel structures shall 'e coated with antiB

corrosi%e s,ste$.

O@) Slide Gates and Screens

Slide Gates and Screens" as &er @S9 ;0 conor$ing to @S9 0; Gr. A"shall 'e designed or worst co$'ination o o&erating and $aintenancecondition. All steel co$&onents shall 'e coated with antiBcorrosi%e &aints,ste$. owe%er" all guides o slide gates and screens shall 'e ostainless steel o Grade A@S@ 80>L.

O@@) oundations

The design o the tower oundation structures shall 'e 'ased on @S9 >;as er wor-ing stress $ethod or worst load co$'ination as &er clause1... @n case o load co$'ination DL 1. L" the li$it state $ethodas &er @S9 >; shall 'e ado&ted.

oundation shall 'e chec-ed or saet, against o%erturning" sliding andu&lit. hile chec-ing sta'ilit, o the structures" neglect a%oura'l,acting loads ro$ water ill" soil co%er 'e,ond the edge o theoundation. igh ground water le%el u& to inal graded ground le%el shall'e considered to ta-e into account 'uo,anc, eect.

The oundation shall 'e o $ini$u$ MB grade concrete resting o%er

100 $$ thic- PCC 1989; la,ers. Clear co%er o concrete shall not 'eless than 0 $$.

Pile oundation i ado&ted shall 'e designed in accordance with @S9=11(PartB@ SecB@" @@ and @@@).



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Generall, net tension should 'e a%oided in the oundations&iles or theshell su&&ort oundation unless s&eciicall, &er$itted ', the #wner.

hile accounting or o%er 'urden o the soil or chec-ing the oundation

against u&Blit" dead weight o the soil directl, a'o%e the &ile ca& or ringrat" as the case $a, 'e" shall onl, 'e considered" neglecting theweight o soil in the cone o u&Blit a'o%e the oundation.

The oundation structures will 'e su'7ected to ollowing loading ande2tre$e load co$'ination case shall 'e considered or design.

1. Most critical orces transerred ro$ su&erstructure or the%arious load co$'inations.

. *&lit orces8. Loading due to oundation settle$ent>. Concentrated local loading ro$ colu$n nodes

. Ther$all, induced local loading where su&&l, cul%erts &assthrough the oundation structures without structural isolation.

;. Surcharge o . ts+.$.

C 'asin surcharge load shall also 'e considered in addition to theother rele%ant loads or the design.

O@@@) ill Su&&ort Structures and #ther Structures

The sel weight o the &ac- su&&ort structures shall 'e 'ased on theweight o the &ac-ing including weight o standing" running and dri&&ingwater" other o&eration and &luggingchoc-ing (de'risscaling) loads" etc.

in accordance with $anuacturerFs data. @n addition" a li%e load o 100-g$shall also 'e considered or the design o su&&orting structures.

or other structures li-e wal-wa,s" &lator$s" etc. a li%e load o >00-gs+.$ shall 'e considered. and railings shall 'e designed orhori/ontal load o ;0 -g$.

ind delector walls and an, other structural ele$ents shall 'edesigned or a hori/ontal wind load o 0 -+s+$ or as &er$anuacturerFs reco$$endations" whiche%er is higher. Ther$al loadingshall 'e as &er $anuacturerFs reco$$endations. 4arth+ua-e loadingshall 'e considered 'ased on criteria gi%en or cooling tower. 5es&onse

s&ectru$ anal,sis shall 'e considered.

Design o 5CC $e$'ers shall 'e 'ased on @S9 >;9000 with li$itingcrac- width o 0.1 $$.

The cold water 'asin sla'rat shall or$ the co$$on oundation or the&ac- su&&ort structures. The oundation shall 'e designed or the $ost



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critical orces transerred ro$ C 'asin 3 ill su&&orting structuresincluding loads introduced ', constructional e+ui&$ents and cranede&lo,ed or ill su&&orting structure or shell erection.

O@6) 5e+uire$ents or Concrete and 5einorce$ent

Structural concrete shall 'e o design $i2 co$&l,ing with the rele%ant&ro%isions o @S codes or an, @nternational Code o Practice asa&&ro%ed ', the #wner.

Dura'ilit, o the concrete shall conor$ to se%ere e2&osure categor, as&er Ta'le 1= o @S9 >; e2ce&t noted s&eciicall, otherwise. Mini$u$ce$ent content o all 5CC structures shall 'e 8;0 -gcu$ e2ce&t incase o concrete 'lended with GG!S s&eciied a'o%e 3 &iling.

5einorce$ent shall coner to grade e >1 as &er @S9 1; e2ce&t

noted otherwise. All reinorce$ents used in 5CC structure shall 'ecorrosion resistant o $arine grade. Colu$n reinorcing 'ars shall 'ecareull, anchored in the shell and oundation. The anchoring lengthshall not 'e less than 0 ti$e the dia$eter o the 'ars.

All oundations structures shall 'e &ro%ided on all sides with a $ini$u$reinorce$ent o 0.1? o gross crossBsectional area distri'uted o%erto& and 'otto$ aces.

The $ini$u$ grade o concrete o structural co$&onents o coolingtowers shall 'e as ollows in accordance with @S9 >;.

a) Shell and 5a-er Colu$ns 9 MB>0 grade') PreBcast &reBstressed ele$ents 9 MB8 gradec) All other 5CC concrete 9 MB80 graded) PCC encase$ent concrete e2ce&t &iles 9 MB gradee) Piles (with #PCPPCPC) 9 MB grade) Tower oundation 9 MB gradeg) Mud $at PCC 9 MB10 grade

Coarse and ine aggregates shall 'e s&eciall, selected to ensure thatthe, are not susce&ti'le to al-alichloride attach or &rone todisintegration at high te$&eratures. @n &articular li$estone aggregatesshall ne%er 'e used. The $a2i$u$ si/e o coarse shall not 'e larger

than 1th narrowest di$ension 'etween reinorce$ent 'ars not $orethan 0 $$.

ashing and screening o coarse and ine aggregates to re$o%e ines"dirt or other deleterious $aterials shall 'e carried out ', a&&ro%ed$eans as directed ', the 4ngineerBinBcharge.



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The water ce$ent ratio ', weight shall 'e 0.> $a2i$u$ including ree$oisture in the aggregates" and slu$& should 'e suita'l, decided to&ro%ide good +ualit, concrete wor-.

O6) Ad$i2tures

Ad$i2tures $a, 'e &er$itted to 'e used in accordance with rele%ant @Scodes to $odi, the rate o hardening or setting" to i$&ro%e wor-a'ilit,or as an aid to control concrete +ualit,. The #wner reser%es the right todirect the contractor to conduct la'orator, tests or use test data" orother satisactor, reerence 'eore granting a&&ro%al. The cost o alltests conducted shall 'e 'orne ', the contractor. The ad$i2ture shall'e used in strict accordance with the $anuacturerFs directions andoras directed ', the #wner. No e2tra &a,$ent will 'e $ade to thecontractor on account o using ad$i2tures.

Particular attention $ust 'e gi%en to concrete &lace$ent 'ecause o thethin wall section and the &resence o reinorcing steel. Consolidation oconcrete shall 'e ', %i'ration. 5e$o%al o air and water at the or$surace shall 'e ', %i'ration and rodding. Particular attention shall 'e&aid to accuratel, sha&e the corners at all o&enings.

Point o discharge o the concrete in to the or$s 'e 100 $$ $a2.a'o%e the concrete surace. Concrete shall 'e de&osited ina&&ro2i$atel, le%el la,ers not greater than >00 $$ dee& unless&er$itted otherwise.

Concrete in the cooling tower shell in each lit shall 'e so laid that the

no. o %ertical or inclined construction 7oints are $ini$i/ed to the e2tent&ossi'le. ori/ontal construction 7oints shall 'e $aintained at unior$s&acing throughout the height o the cooling tower as &er the directionso the #wner.

S&ecial attention shall 'e &aid to &ro&er curing o %ertical aces o thecooling tower shell so that these do not re$ain dr,. All thin walledstructural $e$'ers shall 'e &rotected ', $eans o curing agents. @t isreco$$ended to use a curing agent or the cooling tower shell&ro%iding additional &rotection li-e a single trans&arent cooling with a$aterial 'ased on %in,l $i2ed &ol,$er. @nside ace o the shell should'e &rotected ', a second &ig$ented coating o the na$e 'ase $aterial.

An, other $ethod o curing" i &er$itted ', the #wner $a, 'e used.

Sa$&ling and testing o concrete shall 'e carried out as stated inTechnical S&eciication elsewhere and as &er rele%ant @ndian StandardCodes. owe%er" ollowing $ini$u$ tests shall 'e carried out"irres&ecti%e o whate%er stated otherwise9



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Test o co$&ressi%e strengthColu$ns E 1 Set o 8 cu'es &er colu$nShellB sets o 8 cu'es &er cli$'ing section

O6@) Co%er to 5einorce$ent

*nless indicated otherwise the clear concrete co%er or reinorce$entshall 'e as &er @S Codes.

The correct co%er shall 'e $aintained ', ce$ent $ortar s&acerscu'esor other a&&ro%ed $eans" reinorce$ent or ooting&ile ca&s" grade'ea$" and sla's on su'Bgrade shall 'e su&&orted on &reBcast concreteco%er 'loc- as a&&ro%ed ', 4ngineerBinBcharge. The use o &e''les orstones as co%er 'loc-s shall not 'e &er$itted.

The da,s crushing strength o ce$ent $ortar cu'es&reBcast

concrete co%er 'loc-s shall 'e at least e+ual to the s&eciied strength oconcrete in which the cu'es 'loc-s are e$'edded.

The $ini$u$ clear distance 'etween reinorcing 'ars shall 'e inaccordance with @S9>; (latest edition) or as s&eciied elsewhere in thiss&eciication.

All la&&ing o reinorce$ent 'ars in the cooling tower shell shall 'e ',la&&ing as &er rele%ant codal &ro%isions. Prior a&&ro%al o the #wnershall 'e ta-en or deciding the $ethod o la&&ing the reinorce$ent 'arsin the shell.

Tolerances or the cooling tower construction shall 'e in accordancewith the ollowing9

i) Shell wall centerline in hori/ontal &lane $easuredradiall, at $id &oint on a 8$ wide chord is 1 $$.

ii) Shell wall centerline in $eridional &lane $easured o%er a height o1$ is 10 $$.

iii) Shell thic-ness is 10 $$ or B$$.i%) ori/ontal radius o shell at an, section other than shell 'ase is

0 $$.%) ori/ontal radius at shell 'ase is >0 $$.

O6@@) Chec-ing o shell geo$etr,

Chec- or a'solute &ositions $a, 'e carried out ro$ ground stationsarranged at not $ore than 10 degree &lan angle a&art. 5eadings ohori/ontal radius shall 'e ta-en at e%er, ;$ height or wee-l, duringconstruction &eriod whiche%er is $ore re+uent.



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@ the &er$issi'le di$ensional tolerance are e2ceeded the #wner willinstruct the contractor" in writing" to sto& construction o the shell. TheContractor shall then e2a$ine the situation and su'$it a re&ort to the

#wner who $a, re+uire the contractor to de$onstrate ', calculationsthat the structural integrit, o the shell will not 'e i$&aired as a result othe i$&erections. The calculations shall 'e su'$itted to the #wner" ora&&ro%al" 'eore construction will 'e &er$itted to &roceed.

@ in the o&inion o the #wner the calculations show that the integrit, othe shell could 'e threatened" the Contractor will 'e re+uired to su'$itto the #wner detailed arrange$ent and su&&orting calculations to setright the shell geo$etr, or a&&ro%al" 'eore construction will 'e&er$itted to &roceed.

The cost o carr,ing out the calculation" an, re$edial wor- re+uired and

idle ti$e or an, dela,s to the construction &rogra$$e as a result odi$ensional tolerances 'eing e2ceeded will 'e 'orne ', the contractor.

Ad7ust$ent to the tower shell line on the 'asis o the sur%e, results shall'e $ade graduall,Q li$iting the $a2i$u$ change o direction ro$ thee2isting %ertical shell &roile to 'e not $ore than an angular change o10 $$ $easured o%er 1$ o height. An, such ad7ust$ent shall 'e$ade with ull -nowledge and consent o the #wner.

The contractor shall carr, out an asB'uiltBsur%e, o each lit o the shell.The results o these chec-s will 'e recorded on a suita'l, de%elo&eddrawing o the shell ro$ which it will 'e &ossi'le to locate the sur%e,

chec- &oint. A co&, o these results will 'e &resented to the #wner &riorto co$$encing the ne2t shell &our.

The contractorFs shell construction &rocedures shall include or&ro%iding the #wner with the acilities and a reasona'le ti$e &eriod as$a, 'e re+uired to carr, out an inde&endent chec- o the co$&letedwor-s.

Suita'le co$$unication s,ste$ such as tele&hone" wirelesse+ui&$ents" etc. shall 'e &ro%ided ', the contractor so that theco$$unications are &ossi'le at dierent ele%ations o the tower ro$the ground during construction.

All &iling wor- shall 'e carried out ', s&ecialist su'contractor a&&ro%ed', the #wner. @nitial &ile load test shall 'e carried out or at least 8 setso &iles or direct co$&ression and lateral load.

Since the eecti%e action o the &iles will de&end on the ado&ted$ethod o construction" the contractor shall guarantee that the &iles" as



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constructed ', the su'Bcontractor" shall eecti%el, trans$it the$a2i$u$ loads which can 'e i$&osed on the oundation soil andcorres&onding $a2i$u$ delections.

O6@@@) General 5e+uire$ents

i) The 'asin sla' shall 'e di%ided into two e+ual &arts ', a &artitionwall designed to withstand ull h,drostatic &ressure" with oneside e$&t,. The 'asin construction 7oints shall 'e $adewatertight ', in7ection o che$ical grout through ni&&les. The'asin construction shall 'e tested or water tightness" inaccordance with @S9 880 (Part @) (Latest edition). The cost o thetest and an, rectiication and reBtest i re+uired is dee$ed to 'eincluded in the contractorFs +uoted &rice. An, cost o illing ande$&t,ing o the 'asin and to recti, deects shall also 'e 'orne', the contractor.

ii) P6C ri''ed water sto&s with central 'ul' shall 'e used wheree2&ansion 7oints are en%isaged. The $ini$u$ thic-ness o P6Cri''ed water sto&s with central 'ul' will 'e 10 $$ and $ini$u$width 0 $$.

iii) The 'asin loor o each co$&art$ent shall 'e &ro%ided with aslo&e o not less than 1 in 00 towards su$& or dewatering.ro$ su$&" the water will 'e drained ', C.@. drain &i&e"e$'edded 'elow the 'asin loor" into a drain cha$'er outsidethe tower 'asin or as &er the arrange$ents descri'ed elsewherein the tender docu$ent. Suita'le sluice gates (rising s&indle

t,&e) conor$ing to @S9 80> or sluice %al%es shall 'e &ro%ided inthe drain cha$'er or an, other arrange$ent s&eciiedelsewhere in the tender docu$ent. Suita'le o&erating &lator$with access ladders or o&erating the gates or %al%es and &i&es"shall 'e &ro%ided in the drain 'o2.

i%) A 0 $$ high sill shall se&arate the &ond loor ro$ the toweroutlet.

%) *nior$ surace on the to& o 'asin loor shall 'e &ro%ided. @ncase undulated surace is o'ser%ed" a to& o la,er o $ini$u$ $$ thic- 1.8 $i2 $ortar to 'e &ro%ided to achie%e unior$

surace.

%i) ill will 'e o il$ t,&e su&&orted on 5CC 'ea$. il$ ill should'e characteri/ed ', reduced air &ressure losses" and shall notsusce&ti'le to clogging. Design and acing o the il$ ill shall 'esuch as to e2&ose high airwater surace with $ini$u$ air&ressure dro&.



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The sluice gate s shall 'e structural steel with antiBcorrosi%e coatings&eciied elsewhere. Nu$'er o sluice gates and re$o%a'le screenshall 'e two () &er tower. Pro&er ru''er seal shall 'e &ro%ided so as to

a%oid an, lea-age o water.

The ru''er seal &ro%ided or the sluice gate s 'e tested in accordancewith the rele%ant @ndian Standard Code. Sluice gate s shall 'e chec-edor water tightness and s$ooth o&eration in dr, and wet conditions.

Suita'le acilities" as a&&ro%ed ', the #wner" shall 'e &ro%ided orhandling o sluice gates and screens.

A screed or concrete la,er not less than 100 $$ thic- and o grade notwea-er than 1989; $i2 conor$ing to @S9 >;B000 shall 'e &ro%ided'elow the cold water 'asin and other li+uid retaining structures.

Lean concrete 'elow other oundations and underground structures"unless noted otherwise shall 'e 1989; no$inal $i2 (with aggregate ono$inal si/e >0 $$ $a2i$u$) and shall 'e at least 100 $$ thic-.

All e2&osed suraces o concrete including surace o cooling tower shellshall 'e gi%en two or $ore coat o water&roo ce$ent &aint o a&&ro%ed$a-e and colour.

*nless noted otherwise all concrete surace which are in contact withthe earth shall 'e a&&lied with anticorrosi%e coat s,ste$.

ater &rooing and &lastici/er ad$i2tures conor$ing to rele%ant @Scodes $a, 'e added as &er $anuacturerFs instruction to the concretesu'7ect to a&&ro%al o the #wner.

The tower shall 'e &ro%ided with two nu$'ers e2ternal 5C staircase"leading to a hea%, dut, door gi%ing access to the distri'ution s,ste$.Staircase shall 'e $ini$u$ 1000 $$ wide (clear)" with landings o$ini$u$ width o 1000 $$ at not $ore than 00 $$ height inter%alsunless a&&ro%ed otherwise. The ste&s shall ha%e a rise o a'out 1$$ and tread o a'out 0 $$. AntiBs-id nosing at each ste& shall 'e&ro%ided.

Mini$u$ si/e o all doors shall 'e 100 $$ high (clear) and 100 $$wide (clear). The door shall 'e o steel with antiBcorrosi%e coating o&ol,urethane as s&eciied elsewhere. owe%er" 5P $aterial ore+ui%alent $a, also 'e used su'7ect to a&&ro%al o the #wner. The doorshall 'e air tight when closed.



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The hand railing on 'oth sides o the staircase shall 'e gal%ani/ed withthree rails o 8 $$ N! &i&es conor$ing to $ediu$ class as &er@S918=" and &osts conor$ing to $ediu$ class as &er @S918= o 8$$ dia gal%ani/ed &i&es s&aced not $ore than 1. $ centers. The to&

hand rail shall 'e at 1000 $$ a'o%e the ste&s. Co$&lete hand railsshall 'e a&&lied with antiBcorrosi%e coating s,ste$ as s&eciiedelsewhere.

All gal%ani/ation wor- shall ha%e ;10 g$s+.$ o de&osit.

A&&ro%ed wal-wa,s and &lator$s shall 'e &ro%ided inside the tower atdistri'ution &i&e le%el. These wal-wa,s and &lator$s shall &ro%ide saeand clear access to all s&ra,ers and all distri'ution &i&es. A reinorcedconcrete &lator$ o 100 $$ clear width shall 'e &ro%ided around thetower %al%es. #ther wal-wa,s shall 'e at least ;00 $$ wide with 0$$ ($ini$u$) saet, -er's along each edge. Access wa,s shall 'e

clear o all o'structions such as distri'ution &i&e su&&ort 'ea$s" driteli$inator su&&ort 'ea$s etc. The wal-wa,s shall 'e &ro%ided withtrans%erse slots or other o&ening which will &er$it the ree &assage oair and water.

ot dou'le di& gal%ani/ed handrails as descri'ed a'o%e shall 'e&ro%ided on all sides where there is a ris- o alling through the ill.

5einorced concrete &lator$s 1. $ clear width all around the towercircu$erence shall 'e &ro%ided on the tower or i2ing o a%iationwarning light at le%els s&eciied elsewhere. Two () dia$etricall,o&&osite gal%ani/ed MS caged ladders" ;00 $$ wide" $ade out o ;

$$" 2 10 $$ lats or ull height o the tower shall 'e &ro%ided as &er@S9 8;=;.

The ladder shall ha%e 0 $$ dia rungs at 800 $$ centers" with sta,sat e%er, 0 $$" connected to the concrete shell and gal%ani/ed MScaging consisting o 0 $$ 2 0 $$ %ertical cage lats on the e2teriorsurace o each cooling tower u& to throat. A'o%e throat le%el" theseladders shall 'e continued along the inside surace o the tower u& tothe to& o the tower. A 5CC landing o $ini$u$ si/e 1$21$ withgal%ani/ed handrails and gal%ani/ed steel door at the throat orinterchange to 'e &ro%ided. @n addition to the to& &lator$" inter$ediatelandings o 1.0$ 2 1.0$ with handrails 'e &ro%ided at e%er, to 10 $

height o the MS ladders throughout. So$e o these landing le%els shall'e suita'l, ad7usted to gi%e access to a%iation warning 'eacons or$aintenance. andrails as descri'ed a'o%e shall 'e &ro%ided on all&lator$s. The ladder leading to the to& &lator$ shall ha%e a&&roachro$ ground %ia the 5CC staircase.



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@n order to &ro%ide a&&roach or $aintenance o shell (inside 3 outsideorces)" all &lator$s shall ha%e 0 $$ wide radial o&enings shall 'e&ro%ided in the &lator$ loor at locations a&&ro%ed ', #wner. Ade+uatenu$'ers o $$ internal dia$eter &uddle langed C.@. &i&es shall 'e

e$'edded in this &lator$ or &assing ro&es during $aintenance otower shell.

Steel gratings" where re+uired" shall 'e a'ricated out o steel lats with$ini$u$ thic-ness o ; $$ thic-ness o a'ricated grating shall 'e 8$$ with lats so arranged as to ha%e a $a2i$u$ o&ening or $$ orless. Treads or staircases" where needed" shall 'e o si$ilar gratingconstruction 'ut &ro%ided with toe lats o ; $$ thic-" and nonBs-idnosing in an a&&ro%ed $anner e2tending u& to 100 $$ a'o%e thewal-wa, surace. All steel gratings shall 'e gal%ani/ed and a&&lied withanticorrosi%e coating s&eciied elsewhere.

The $ild steel &arts o structures used in cooling towers shall 'e hotdou'le di& gal%ani/ed unless it is coated with a se&arate antiBcorrosi%ecoating s,ste$. The $ini$u$ coating shall 'e ;10 g$s+.$ and shallco$&l, with rele%ant @S codes. Gal%ani/ing shall 'e chec-ed and testedin accordance with @S9 ;=. The gal%ani/ed shall 'e ollowed ', thea&&lication o an etching &ri$er and antiBcorrosi%e iB'uild e&o2,coating s,ste$ o DT ;0 $icrons. All welding shall 'e done 'eoregal%ani/ing. An, site 7oints re+uired to 'e carried out ater gal%ani/ingshall 'e either langed or screwed 7oints. Nails" nuts" 'olts and allco$&onents co$ing in direct contact with water shall 'e o stainlesssteel o A@S@ 80> or e+ui%alent.

The urnished ground le%el shall 'e &a%ed or .0$ width all round theouter edge o the cold water 'asin. The &a%ing shall consist o 10 thic-5CC sla' o MB0 grade. The $ini$u$ reinorce$ent shall 'e 10 $$dia s&aced 10 $$ center to center 'oth wa,s to& and 'otto$. The5CC sla' shall 'e o%erlaid 100 $$ thic- MB10 PCC $at and 800 $$well co$&acted sand la,er. All around &eri&heral 5CC drain leading todrain cha$'er shall 'e suita'l, &ro%ided.

Ite$" to +e po*i%e% .Genea'/

a. Mini$u$ two nos. Cage ladder conor$ing to @S9 8;=;" ;00 $$wide and $ade o hot dou'le di& gal%ani/ed ;0 $$ 2 ; $$

thic- lats with 0 $$ dia$eter rungs at 800 $$ centres withsta,s at e%er, 1. $ connected to the wall. The ladder shall 'e&ro%ided with hot dou'le di& gal%ani/ed MS cage consisting o $$ 2 $$ stra&s at 00 $$ centres with i%e nos. o 0$$ 2 ; $$ %ertical cage lats throughout the co$&lete length othe ladders. The cage ladders shall 'e co$&lete with all thenecessar, accessories" e$'edded &arts" hardware" etc. hot



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dou'le di& gal%ani/ed as &er @S9 >= with ;10 g$s+.$ o Rinccoating as &er s&eciications and drawings or as directed ',4ngineerBinBcharge" co$&lete in all res&ects.

'. G@ andrails o 1. $ high with &osts $ade o 8 N! hea%, dut,class &i&es conor$ing to @S9 18= &laced at 1.$ cc $a2. andthree hori/ontal rails ('etween an, two &osts) o 8 N! hea%,class conor$ing to @S9 11;1. The handrails shall 'e co$&letedwith all the necessar, accessories" e$'edded &arts" hardware"etc. hot dou'le di& gal%ani/ed as &er @S9 >= with ;10 g$s+.$o /inc coating as &er s&eciications and drawings or as directed', 4ngineerBinBcharge" co$&lete in all res&ects.

c. Two nos. Slide gates o suita'le o&ening si/e conor$ing to @S9

;0 co$&lete with e$'edded &arts o SS 80>L" guide ra$eso SS 80>L" gate conor$ing to @S9 0; Gr. A" side seal o

4PDM Musical Note" 'otto$ seal o 4PDM" all other accessoriesand hardware necessar, to install and o&erate the s,ste$ as&er s&eciications and drawings or as directed ', 4ngineerBinBcharge" co$&lete in all res&ects. The slide gates shall generall,$eet the ollowing re+uire$ents9

1. Standard 0 @S9 ;0

. De&th o water colu$n ordesign

0 8 $

8. Guide ra$e (4$'edded inConcrete)

0 MSDG with SS 81; L sealingsurace

>. Gate (including su&&ortingra$e)

0 @S 0; Gr. A

. Slide &lates o gate 0 SSB80> L

;. Slide Seal 0 4PDM Musical note conir$s to@S9 11

. !otto$ Seal 0 4PDM conir$s to @S9 11

. Painting 0 S&eciied elsewhere

=. asteners 0 SS 80>

d. Two nos. Coarse Screens with guide ra$e to 'e suita'l, installed inthe cold water channel and $ade o ; SG wire $esh o SS 80>Lha%ing 1; $$ 2 1; $$ o&enings with trash tra, and e$'edded &arts o

SS 80>L" screen ra$e o CS (gal%ani/ed to ;10 g$s+.$)" guide ra$eo SS 80>L and all other accessories and hardware necessar, to installand o&erate the s,ste$ as directed ', 4ngineerBinBcharge" co$&lete inall res&ects.



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1. Materials 0 SS 80> L

. Mesh Si/e 0 1; $$ 2 1; $$ s+uare o&enings with ;SG wire

8. Su&&orting ra$e 0 MSDG with SS 80>L slide &arts

>. Guide ra$e(4$'edded inConcrete)

0 MSDG with SS 81; L sealing surace

. Trash Tra, 0 MSDG

;. asteners 0 SS 80>

e. Two nos. ine Screens with guide ra$e to 'e suita'l, installed in thecold water channel and $ade o SG wire $esh o SS 80>L ha%ing1 $$ 2 1 $$ o&enings with trash tra, and e$'edded &arts o SS80>L" screen ra$e o CS (gal%ani/ed to ;10 g$s+.$)" guide ra$e oSS 80>L and all other accessories and hardware necessar, to installand o&erate the s,ste$ as &er s&eciications and drawings or as

directed ', 4ngineerBinBcharge" co$&lete in all res&ects.

.

1. Materials 0 SS 80> L

. Mesh Si/e 0 1 $$ 2 1 $$ s+uare o&enings with SG wire

8. Su&&orting ra$e 0 MSDG with SS 80>L slide &arts

>. Guide ra$e(4$'edded inConcrete)

0 MSDG with SS 81; L sealing surace

. Trash Tra, 0 MSDG

;. asteners 0 SS 80>

g. andling acilities o a&&ro%ed $a-e in Cold ater Channel includinga'rication" erection co$&lete with all the necessar, accessories"e$'edded &arts" hardware" etc. hot dou'le di& gal%ani/ed as &er @S9 >=with ;10 g$s+.$ o /inc coating as &er s&eciications or as directed ',4ngineerBinBcharge" co$&lete in all res&ects.

h. Monorails or Slide gates and Screens shall 'e @SM! 800. Monorail trolle,s($anual t,&e) $o%ing o%er @B'ea$s. Chain &ulle, 'loc- (8.0Ton ca&acit,with $ chain) conor$ing to @S988 with $ load chain conor$ing to @S9810= co$&lete with necessar, accessories such as hoo-s" slings etc withhardware as &er s&eciications or as directed ', 4ngineerBinBcharge"

co$&lete in all res&ects.

i. andling acilities on to& o cooling tower including a'rication" erectionco$&lete with all the necessar, accessories" e$'edded &arts" hardware"etc. hot dou'le di& gal%ani/ed as &er @S9 >= with ;10 g$s+.$ o /inccoating as &er s&eciications or as directed ', 4ngineerBinBcharge"



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co$&lete in all res&ects or !rac-ets" hot dou'le di& gal%ani/ed as &er @S9>= with ;10 g$s+.$ coating. Swi%eling t,&e liting ar$ co$&lete withswi%eling 'rac-ets" &ins" etc. along with 0 $$ dia$eter CS &ulle,s" andall the necessar, e$'edded &arts" inserts" hardware" etc. hot dou'le di&

gal%ani/ed as &er @S9 >= with ;10 g$s+.$ coating.

7. $$ dia$eter MS rungs" hot dou'le di& gal%ani/ed as &er @S9 >= with ;10g$s+.$ coating and co$&lete with all accessories as &er s&eciications oras directed ', 4ngineerBinBcharge.

-. MS structural su&&orts in trusses or &i&e with all 'racings" 'rac-ets"cleats" gusset &lates" etc. as &er detailed drawings or as directed includingcutting" a'ricating" hoisting" erecting" i2ing in &osition" welded connectionsand &ainting with 5ed #2ide Rinc Chro$ate &ri$er etc. co$&lete as &ers&eciications or as directed ', 4ngineerBinBcharge.

l. MSDG Access Door with ra$e in hollow $etal construction o .1$ clearheight 2 1.$ clear width 2 >$$ th- with gal%ani/ing to ;10 g$s+.$coating and o 1 Guage sheet with suita'le stieners o sa$e $aterialincluding accessories 3 i2tures li-e ra$e" hinges" latches" hardware etcco$&lete as &er s&eciications or as directed ', 4ngineerBinBcharge.

$. Mini$u$ two nos. o 800N! langed C@ &i&es o Class A t,&e conir$ing @S918; as directed ', 4ngineerBinBcharge shall 'e &ro%ided in the drainsu$&s or sludge re$o%al

n. At least two nos. o 800 $$ dia. Sluice gates conor$ing to @S9 80> ClassB@ asdirected ', 4ngineerBinBcharge shall 'e &ro%ided or sluice o&erations.

o. All the MS &i&ing conor$ing to @S9 8= and MS &lates as &er @S9 0;including 'ends" Ts" el'ows" reducers etc. co$&lete with all the necessar,DGS hardware" gas-ets etc. including a'rication" cutting" aligning"welding" lowering" la,ing" h,droBtesting etc. shall 'e &ro%ided as &ers&eciications or as directed ', 4ngineerBinBcharge or all dia$eter &i&es.

&. Two nos. Dou'le langed !utterl, %al%es o suita'le dia$eter and o a&&ro%ed$a-e conor$ing to AA CB0> !S9 1 with $ating langes andco$&lete accessories and hardware as &er s&eciications includingaligning" erecting" testing etc. co$&lete in all res&ects shall 'e &ro%idedse&aratel, in the CC and AC &i&ing res&ecti%el,.

+. Suita'le MSDG drain ni&&le with suita'le drain &lug or lushing o Pri$ar, ducts and co$&lete with accessories and hardware as &ers&eciications including aligning" erecting" testing etc. all as directed ',4ngineerBinBcharge.



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r. 5e+uired nos. o 0N! 2 00$$ long MS hea%, dut, Stu' connections as &er@S9 1= with isolating 'all %al%es as &er @S9==0 o threaded t,&e or low$easure$ent in &i&es and co$&lete with accessories 3 hardware as&er s&eciications including aligning" erecting etc. and as directed ',

4ngineerBinBcharge.

s. At least our nos. o Dial t,&e &ressure gauges o ; dial si/e as &er @S98;>including stu' connection with isolation 'all %al%e as &er @S9==0 andco$&lete accessories" hardware as &er s&eciications including erecting"testing etc necessar, or installing 3 o&erating the s,ste$ shall 'e &ro%ide.

t. All the underBground &i&ing shall 'e suita'l, surace &re&ared and coated andwra&&edK with e&o2, and i'erglass 5P tissue as &er rele%ants&eciications and as directed ', the 4ngineerBinBcharge.

u. All the a'o%eBground &i&ing shall also 'e surace &re&ared and &ainted on

outside surace as &er rele%ant s&eciications and as directed witha&&ro%ed $a-e and t,&e o &aints" all as directed ', 4ngineerBinBcharge.

%. The P6C il$ ills $ade ro$ %irgin P6C shall 'e *6 sta'ili/ed and o a&&ro%ed$a-e in 'lac- colour ha%ing 11= $$ cross lutes with 0. $$ unior$thic-ness and dou'le edge olding to $eet the re+uire$ents o CT@ codeSTDB18;. @t shall ha%e a heat transer area not less than 1> $ $8.*6 testshall 'e conducted as &er @S# >= and i$&act test as &er ASTMBDB;.The re+uired a$ount o gluing co$&ound to $a-e $odules o ills shall also'e &ro%ided ', the 'idder. The $ini$u$ total height o ill shall not 'e lessthan 1. M and shall 'e su&&lied in i%e () la,ers.

w. AC &i&es o suita'le dia$eters and o class 1 grade as &er @S91= withs&igot end including drilling o holes or i2ing no//les" hoisting" grouting in5CC ducts" erecting" 7ointing with re+uired accessories" testing etc.including end ca&s co$&lete as &er s&eciication and as directed or the ullunctionalit, o the s,ste$ shall 'e &ro%ided.

2. 5e+uired nu$'er o Pol,&ro&,lene No//les o suita'le o&ening si/es to caterto %aried water low rate as &er s&eciication or as directed ', 4ngineerBinBcharge" co$&lete with all the necessar, hardware re+uired or astening theno//les to the AC &i&es including accessories" hardware etc. shall 'e&ro%ided.

,. Ther$al &eror$ance Test in%ol%ing $easure$ent o water low as &er!S910> using &itot tu'e conir$ing to @S#98=;;" air te$&eratures (!T 3D!T) using $echanicall, as&irated Ps,chro$eter" water te$&eratures(T 3 CT) using $ercur, in glass ther$o$eters" air low usingane$o$eter as &er s&eciications and as directed ', the 4ngineerBinBCharge shall 'e done ', the 'idder. All the instru$ents shall 'e cali'rated(at @@T @@SC) within ; $onths &rior to test.



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/. Mini$u$ eight nos. o igh intensit, L4D t,&e redwhite lashing t,&e a%iationo'struction light as &er @CA# and Director General o ci%il a%iationre+uire$ents and with corrosion resistant alu$inu$ casting inished in

sto%e ena$eled control gear suita'le or 00>06" 0/ su&&l," co$&leteas &er s&eciication shall 'e &ro%ided. The lie o A#Ls shall 'e $ore than10 ,ears and with all the necessar, i2ing accessories as directed ',4ngineerBinBcharge. The A#L s,ste$ shall 'e &ro%ided with Photoelectriclight detectors to $onitor north s-, or controlling the a%iation warninglights. The lights should 'e switched on when the a$'ient light goes 'elow8 candelas and switched o when the intensit, is $ore than candelas.The lights should not 'e switched o due to $o$entar, increases in lightintensities due to lightning lashes or an, other short 'ursts o light. Thedetectors should 'e co$&lete with all the accessories" hardware etc.necessar, or installation. The acilit, or AutoManual o&eration shall 'e&ro%ided.

aa. All ca'les shall 'e hea%, dut, P6C insulated" G@ wire lat ar$ored" P6Csheathed" ;011006 grade 5LS co&&er ca'le as &er @S9 1> PartB@with owners a&&ro%al. The ca'le shall 'e cla$&ed at e%er, 0 $$ alongits run and will include all the hard ware re+uired or its i2ing andter$inations etc. The UunctionTer$inal 'o2es should 'e &ro%idedwhere%er re+uired. The ca'le schedule shall 'e as under9

>C 2 10 s+.$$ Co&&er Ca'le or a%iation warning lights

>C 2 ; s+.$$ Co&&er ca'le or &ower rece&tacles" stair case lighting andtail end a%iation warning lights etc.

C 2 . S+.$$ co&&er ca'le or local connection ro$ local Uunction 'o2to a%iation warning lights.

''. The 'idder shall also &ro%ide >06 2 1A single &hase 8B&in outdoor" weather&roo" industrial t,&e switchB Bsoc-et outlets with interBloc- switches anditted with $etal ca&. 5e+uired nos. o weather 3 dust &roo (@PB) 00$$ 2 10$$ 2 100$$ dee& 7unction 'o2 (8> wa,) $ade out o $$ th-G.S. with 4LM4O t,&e ter$inals" glands etc. co$&lete shall also 'e&ro%ided.

cc. A Lighting Distri'ution !oard and Control Panel or A%iation arning Lights

a'ricated ro$ $$ th- sheet steel" dust and %er$in &roo andre$o%a'le gland &lates at to& and 'otto$ with 4LM4O t,&e connectorsand with suita'le earthing including nos. 8A TPN inco$ers" 5C usesand nos. 8A outgoing connections with 5C uses and Co$$onlasher shall 'e &ro%ided. Two in&uts will 'e &ro%ided ', the #wner E onethe $ain su&&l, and the other as stand ',. Auto$atic change o%er with



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suita'le dela, ti$ers with AutoManual o&eration shall 'e &ro%ided ', the'idder.

dd. To care o @CA# and DGCA re+uire$ents" the 'idder shall &ro%ide Te$&orar,

A%iation arning Lights during construction a'o%e the 0$ le%el ro$general ground le%el.

ee. The earthing and lightning &rotection s,ste$ shall 'e as &er @S9 80>8 ingeneral. Air ter$inators $ade out o $ long >0 dia MSDG round 'ar with&ointed to& and cla$&ed at $ini$u$ 8 &oints with hea%, dut, G.@. cla$&sshall 'e &ro%ided. @t shall 'e ensured that 1. $ o the air ter$inator shall'e &ro7ecting a'o%e the to& o the cooling tower.

. A 0 2 ; th- G@ lat Coronal 'and connecting all air ter$inator on one side andto the down conductor on the lower side co$&lete with all the necessar,i2tures" hardware etc. re+uired or installation shall 'e &ro%ided. The

cla$&s used shall 'e G@ and hea%, dut, and shall 'e i2ed a&&ro2 1$'elow the to& o the cooling tower and cla$&ed at the s&acing not $orethan 1$ CC. Also" a 0 2 ; th- G@ lat down conductor co$&lete with all thenecessar, i2tures" hardware etc. re+uired or installation shall 'e included.The down conductors on the to& shall 'e connected to the coronal 'andand on the lower side the, shall 'e connected to the test lin-s. Thecla$&ing shall 'e at 1$ CC with hea%, dut, G@ cla$&s. The downconductors shall 'e in one &iece as ar as &ossi'le. The necessar, 7ointsshall 'e o ull, welded t,&e and not 'olted t,&e e2ce&t at the test lin-.These conductors shall 'e e$'edded in the concrete o the shell with a$ini$u$ co%er o 0$$ and shall co$e out o the concrete at the to& and'otto$ o ring 'ea$.

gg. The 4arth conductor to 'e &ro%ided ', the 'idder shall 'e $ade out o >0 $$Dia. MS round 'ar co$&lete with all the necessar, i2tures" hardware etc.re+uired or installation and shall 'e su&&lied and installed 'etween test lin-on one side and to the earth $at on the other side. 4arthing electrode odia. >0 $$ MS rod 2 8$ long and $a-ing o earth &it as &er @S980>8co$&lete with all the necessar, i2tures" hardware etc. re+uired orinstallation and connection to the earth $at shall also 'e in the sco&e o the'idder.

hh. Te$&orar, lightning &rotection s,ste$ during construction to $eet @CA# andDGCA re+uire$ents shall 'e &ro%ided ', the 'idder" co$&lete with all the

necessar, i2tures" hardware etc. re+uired or installation.

ii. The 'idder shall conduct tests on circuit as &er s&eciication or as directed ',4ngineerBinBcharge.

77. 5e+uired nos. o ther$owel co$&lete with all the necessar, i2tures" hardwareetc. re+uired or installation shall 'e &ro%ided ', the 'idder and he shall



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also &ro%ide re+uired nos. o Te$&erature and Pressure Gauges" 5TDs"low Measuring De%ices" etc. co$&lete with all the necessar, i2tures"hardware etc. re+uired or installation.

--. The 'utterl, %al%es shall 'e &ro%ided with N#NC &otential ree li$itswitches or ! %al%es co$&lete with all the necessar, i2tures" hardwareetc. re+uired or installation.

ll. The %al%es shall generall, $eet the ollowing re+uire$ents9

!utterl, 6al%es9

T,&e 0 Manuall, o&erated Dou'le langed !utterl, 6al%eStandard 0 AA C E 0> !S9 1P#D (Proo oDesign) Test

0 AA C E 0>

#&erating luid 0 ater at >0 deg. C to > deg. C

Design Pressure 0 .0 g.S+.c$.Ma2. dierential&ressure

0 .0 g.S+.c$.

ead loss coe. 0 Ma2. 0.8!od, 0 Cast @ron conir$s to @S9 10 Grade G ;0

or a'ricated steel conir$s to @S90;@S900Shat 0 Stainless Steel A@S@ >10!earing t,&e 0 Sel lu'ricated t,&eDisc seat 0 Nitrile 5u''er!od, Seat 0 SS E 81;@nternal ardware 0 Stainless Steel42ternal ardware 0 igh Tensile Steel

asteners 0 SS E 80> SS E 81;Gland Pac-ing 0 Telon

Gas-ets" 5ings" etc. 0 Nitrile 5u''erAccessories 0 Nos. o N# NC li$it switches #P4NF 3

CL#S4F.

All the 'utterl, %al%es shall 'e co$&lete with graduated &osition indicator"arrow indicating the low direction. The %al%es shall 'e suita'le or erection inan, &osition (ori/ontal 6ertical" etc.). The o&erating $echanis$ shall 'e$ounted directl, on or su&&orted ro$ %al%e 'od,. All the 'utterl, %al%esshall 'e &ro%ided with hand wheel. !utterl, %al%es o si/e 80 N! and a'o%e

shall 'e &ro%ided with reduction gear units. 6al%es shall close in cloc-wisedirection. The hand controls shall 'e di$ensioned to guarantee an eas,$aneu%er under $ost se%ere conditions. The hand controls shall 'e &ro%idedwith loc-ing s,ste$s to a%oid the dis- assu$ing a not desired &osition duringo&eration. The &ulling orce re+uired on the hand wheelBri$ shall not e2ceed80 g. when o&erating the %al%e under ull low and o&erating &ressure. The



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reduction units shall 'e watertight" co$&lete with lu'rication and &ositionindicator.

!all 6al%es9

Standard 0 @S9 ==0

T,&e 0 Threaded

Pattern andConstruction

0 ull 'ore in single &iece

No$inal si/e 0 As s&eciied elsewhere

Design &ressure 0 g".s+.c$.

Material o construction 0 Car'on Steel 6al%es conir$s to@S9 ==0

$$. langes

or %al%es designed as &er AA CB0>" %al%e langes shall conor$ toANS@ !1;.1 Class 1 or C@ %al%es and AA CB0 Class D ora'ricated steel %al%es. The counter langes shall conor$ to AA CB0Class D. or %al%es designed as &er !S9 1 the langes shall 'e as &er!S9 >0>. All the langes shall 'e o sli&Bon and latBace t,&e. langesshall 'e a'ricated ro$ steel &lates conor$ing to @S9 0;.

>.00.00 Pefo$ance G(aantee

Peror$anceAcce&tance test shall 'e carried out or deter$ination o thether$al ca&a'ilit, and %eriication o the guarantee o the cooling towerconstructed at the &ro7ect.

(i) Test shall 'e conducted ', accredited re&resentati%es o thecontractor and owner. The contractor shall 'e gi%en &er$ission toins&ect the tower in ad%ance. ContractorFs re&resentati%es shallwitness all &hases o the test and record the data 7ointl, with#wnerFs re&resentati%e.

(ii) The

Annexure IV Ndct

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Transcript of Annexure IV Ndct