Double Deck Floating Roof

8/13/2019 Double Deck Floating Roof

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Horton Double Deck Floating Roof DesignsRed Book Number: 9105-5Revised: 16/01/2002

Issuing Authority: Ned A. Bacon/Plain ield/!B"Maintenance & Review: Plain ield Pla#e $#ruc#ures %n&ineerin&

0. !co"e: '(is s#andard urnis(es de#ail and dimensional re)uiremen#s or *or#on +ouble+eck ,loa#in& Roo s u #o and includin& 00 . '(e desi&ns com l i#( AP" $#andard 650

A endi !.

A *or#on +ouble +eck ,loa#in& Roo consis#s o # o com le#e decks 3#o and bo##om4 oined b aseries o concen#ric rims ormin& buo an# annular ba s. '(e ou#er annular ba is divided in#osmaller com ar#men#s b radial bulk(eads.

'(e *or#on +ouble +eck ,loa#in& Roo is desi&ned #o loa# direc#l on #(e roduc# #(us reducin&eva ora#ion loss corrosion and ire (a7ard. '(e bo##om deck is subs#an#iall la# (encons#ruc#ed bu# due #o roo le ibili# a small amoun# o #em era#ure &enera#ed condensableva or can be con#ained #o ards #(e cen#er o #(e roo . 8o er #em era#ures ill condense #(eva or back #o li)uid. A seal is used #o close #(e s ace be# een #(e loa#in& roo and #(e s(ell.

AP" $#andard 650 A endi ! re)uires all loa#a#ion com ar#men#s #o be li)uid #i&(# . '(ismeans con#inuous eldin& on one side o ou#er ba radial bulk(eads and all circum eren#ial rims#o #(e #o deck and a#ers#o eldin& (ere #o deck la oin#s cross bulk(eads and rims isre)uired.

"n #(is s#andard #(e diame#er is #(e nominal #ank diame#er in (ic( #(e roo ill be ins#alled.

. !"ecification: AP" $#andard 650 A endi ! % #ernal ,loa#in& Roo s and !B"re)uiremen#s. '(e desi&ns in #(is s#andard &enerall mee# #(e re)uiremen#s o B$ 265 .$ee #000$%$ No#es 8ink or s eci ic di erences.

.% Material: +esi&ns are based on ma#erial i#( a minimum ield s#ren( o 0 ksi.

.# Design oa's: '(e dead ei&(# is #(e me#al ei&(# 3#(eore#ical4 lus #(e ei&(# o #(eaccessories.

a. Roo on $u or#s: ;embers and a##ac(men#s are desi&ned #o su or# #(e dead ei&(#and a uni orm live load o 25 s .

b. Roo ,loa#in&: '(e roo is desi&ned #o loa# under ollo in& loadin& condi#ions:

25 s uni orm live load.8oss o buo anc as in .(.!ollec#ion o a#er on #o deck #o eleva#ion o emer&enc drains.

c. '(e roo is desi&ned #o be air raised durin& cons#ruc#ion.

.( Floatation of Roof on 0.) !"ecific *ravity i+ui': $u icien# on#oon volume isre)uired #o kee #(e roo loa#in& i#( an # o com ar#men#s unc#ured 3a com ar#men# isiden#i ied as an ou#er ba com ar#men# or an annular rin&4 i#( no a#er or live load.
http://notes///852563A600577DE7/2416762E59280CC9852563C4006A702C/29CA15494A149335862563240040BE01http://notes///852563A600577DE7/2416762E59280CC9852563C4006A702C/29CA15494A149335862563240040BE01


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., Design -roce'ure: '(e desi&ns in #(is s#andard (ave been develo ed usin& com u#erro&ram 50959A.

. *eneral /otes: +esi&ns in #(is s#andard are based on /16 la#e e ce # (ere no#ed.!onsul# Plain ield Pla#e $#ruc#ures or s ecial #(icknesses or (ere corrosion allo ance iss eci ied.

!onsul# Plain ield Pla#e $#ruc#ures or roo s loa#in& on li)uids o s eci ic &ravi# lo er #(an0.


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Figure . 0 4y"ical Deck ayout

Figures %.0a and %.0b s(o # ical vie s o *or#on +ouble +eck ,loa#in& Roo s. Figure %.0a is# ical o #(e cen#er drainin& roo desi&ns &iven in #. . A sin&le slo e roo is one in (ic( #(e #odeck (as a cons#an# slo e 3minimum slo e e)uals 1/ :124 rom #(e ou#er rim #o #(e cen#er o #(eroo . 4ables #. b and #. c &ive desi&ns or sin&le slo e roo s u #o and includin& 190 diame#er.

Figure %.0b is a # ical vie o a reverse slo e # e roo . +esi&ns or #(e reverse slo e # e rooor diame#ers &rea#er #(an 190 u #o and includin& 00 are &iven in 4able #.%a. '(e reverseslo e roo (as a #o deck coned u in #(e cen#er. '(is reven#s #(e ou#er rim rom becomin&e #remel (i&( #(us allo in& #(e use o mec(anical s(oe seals on lar&e diame#er double deckroo s.

,or &eneral sec#ion de#ails use !t' For5 Drawings #%%,$ #(rou&( #%%,$ 0.

@se $#d + & 6B or miscellaneous roo eldin& de#ails.


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Figure %.0a $ 4y"ical !ingle !lo"e Roofs


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Figure %.0b $ 4y"ical Reverse !lo"e Roof

%. Roof !u""orts: '(e +ouble +eck roo is urnis(ed i#( ad us#able roo su or#s. '(eroo su or#s are #o clear all i##in&s and rollin& ladder run a an&les b a minimum o 1 -0.Roo su or#s s(all clear movin& ar#s o i e drain b a# leas# 2 and o#(er ar#s o #(e i edrain b a# leas# 12 . 3 0 $ No#es 8ink &ives si7es desi&n rocedures and ermissibleloads or ad us#able su or#s. '(e roo su or#s are loca#ed on +ouble +eck roo s so #(a##(e sleeves are a##ac(ed #o ei#(er bulk(eads or circum eren#ial rims b means o ver#icals(ear la#es. $ee Figure #.%'. $ee Figures %.0a and %.0b or loca#ion o su or#s. $ee4ables #. b2 #. c and #.%a or #(e number o su or#s.

%.% Drainage !yste5s: A closed draina&e s s#em is &enerall used as #(e rimar drain #oremove a#er rom #(e roo . = en drains can be used as #(e rimar drain bu# do no# mee##(e in#en# o AP" $#andard 650 A endi !. 8oca#e #(e rimar drain a# #(e cen#er o #(e rooor sin&le slo e roo s. ,or reverse slo e roo s loca#e rimar drains 1 - inside o #(e lorim. 8oca#e one drain near #(e rollin& ladder run a . $ee Figure %.0b.
http://notes///852563A600577DE7/2416762E59280CC9852563C4006A702C/5465DF4BBF54E78D8625638E005F2CC6http://notes///852563A600577DE7/2416762E59280CC9852563C4006A702C/5465DF4BBF54E78D8625638E005F2CC6


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$ee 3%0%No#es 8ink or number and si7e o rimar drains.

%mer&enc over lo drains 3see 3%0%No#es 8ink 4 are also re)uired.

%.# Roof Manholes: ,or all cen#er drainin& # e roo s 3see Figure %.0a 4 rovide 1-2diame#er man(ole #(rou&( bo#( decks near #(e cen#er o #(e roo . (ere #(e roo diame#ere ceeds 250 rovide an addi#ional roo man(ole or eac( s(ell man(ole 3ma imum o 4 a##(e eri (er o #(e roo . (en a i e drain is used urnis( a 0 diame#er man(ole 3 0diame#er or 6 i e drain4 in lace o #(e 2 diame#er man(ole a# #(e cen#er #o ermi# drainremoval.

,or reverse slo e roo s 3see Figure %.0b 4 rovide a minimum o 2-2 diame#er man(olesabou# -0 rom #(e lo rim and orien#ed a ro ima#el diame#ricall o osi#e eac( o#(er. "#is re erable #o orien# #(ese man(oles as close as ossible on a radial line #o #(e s(ellman(oles. (en i e drains are used make one o #(ese man(oles 0 diame#er 3 0diame#er or 6 i e drain4 #o ermi# drain removal. ,or roo s over 250 diame#er rovide oneaddi#ional roo man(oles or eac( s(ell man(ole 3ma imum o 24 a# #(e eri (er o #(e roo .8oca#e #(ese addi#ional man(oles er endicular #o #(e diame#ric line #(rou&( #(e 2 man(oles(ic( are near #(e lo rim.

%.( Deck Manholes: 20 diame#er ven#ed man(oles are re)uired #o ermi# access in#o eac(com ar#men# o #(e +ouble +eck roo . %ac( man(ole cover mus# be secured b a osi#ive(old-do n device. $ee !t' Dwg 6 #6. ,or #(e number o deck man(oles see 4ables#. b2 #. c and #.%a. '(e #o ed&e o eac( man(ole neck s(ould be a# leas# 6 (i&(er #(an#(e ma imum a#er level a# #(e emer&enc drains.

%., Ri5 7ent: A 6 rim ven# is re)uired or eac( roo i#( a mec(anical s(oe # e seal(ere #(e bo##om o #(e s(oe seal e #ends in#o #(e roduc# more #(an a ro ima#el . $ee!t' Dwg * or de#ails. 8oca#e #(e rim ven# a ro ima#el 1>0 rom #(e inle# line. +o no#urnis( #(is ven# on roo s i#( oam illed seals.

%. *age Hatch: =ne > diame#er &a&e (a#c( is su lied i#( eac( roo . $ee !t' For5

Dwg #%00$R 3 . '(is &a&e (a#c( ma be a##ac(ed #o a &a&e i e as o #ional e)ui men#(en s eci ied b #(e Purc(aser.

%.) *age 1ell: A &a&e ell is urnis(ed onl (en #(e Purc(aser s eci ies an au#oma#ic&a&e. Bo#( au#oma#ic &a&e and &a&e ell are o #ional.

%. Auto5atic 6lee'er 7ents: '(e au#oma#ic bleeder ven# ermi#s #(e release o air va ormi #ure rom under #(e roo (ile #(e #ank is bein& illed and #(e roo is res#in& on i#ssu or#s. '(e ven# au#oma#icall closes a #er #(e roo loa#s. (en #(e #ank is em #ied #(even# o ens be ore #(e roo lands. "# is ull o en (en #(e roo is on i#s su or#s allo in& air#o en#er and reven#in& a vacuum rom ormin& under #(e roo .

$ee 3%0 $( No#es 8ink or ca aci#ies o au#oma#ic bleeder ven#s. $ee Figures %.0a and %.0b

or loca#ions o #(ese ven#s. ,or reverse slo e roo s a minimum o ven#s s(all be ins#alled. All ven#s mus# clear i##in&s and #(e rollin& ladder run a an&le b a minimum o 1 -0.

-ressure$7acuu5 relief vents are s#ron&l discoura&ed as a subs#i#u#e or au#oma#icbleeder ven#s. ,urnis( #(ese relie ven#s onl (en #(e urc(aser insis#s and onl a #errovidin& #(e ollo in& reasons or concern.

14 Produc# va or and residue collec#ion on #(e ven# alle# can res#ric# #(e relie ven# romo enin& or can c(an&e #(e o enin& ressure. Ad(esion s#ickin& o #(e alle# #o #(e sea#can cause ressures ar be ond desi&n condi#ions. ,ailure o #(e ven# #o con#rol vacuum
http://notes///852563A600577DE7/2416762E59280CC9852563C4006A702C/8FF85B4B797A28828525639C002F3A7Fhttp://notes///852563A600577DE7/2416762E59280CC9852563C4006A702C/8FF85B4B797A28828525639C002F3A7Fhttp://notes///852563A600577DE7/2416762E59280CC9852563C4006A702C/CF7A4F516263FAC286256392006A6280http://notes///852563A600577DE7/2416762E59280CC9852563C4006A702C/8FF85B4B797A28828525639C002F3A7Fhttp://notes///852563A600577DE7/2416762E59280CC9852563C4006A702C/8FF85B4B797A28828525639C002F3A7Fhttp://notes///852563A600577DE7/2416762E59280CC9852563C4006A702C/CF7A4F516263FAC286256392006A6280


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can cause si&ni ican# roo dama&e durin& roduc# i#(dra al. ,re)uen# main#enance o#(e ven# is essen#ial (o ever acce #ed (eal#( and sa e# rac#ices ro(ibi# or res#ric#access #o #(e loa#in& roo (ile in service.

24 Cas ressure under a loa#in& roo durin& ini#ial illin& o era#ions mus# be con#rolled #oreven# #(e roo rom li #in&. Relie ven# se##in&s mus# #(ere ore be se# ell belo aressure e)ual #o #(e avera&e ei&(# er uni# area o #(e #o#al loa#in& roo s#ruc#ure.+urin& #ank o era#ion #em era#ure and barome#ric ressure c(an&es can resul# in &asorma#ion under #(e loa#in& roo . Cas orma#ion occurs a# ressures &rea#er #(an #(even# se# ressure and ill resul# in emissions.

Design an' si8ing o ressure-vacuum relie ven#s ma be made b #(e urc(aser or b !B"usin& urc(aser su lied in orma#ion. Refer to 3%0 $%No#es 8ink for contract con'itionsan' infor5ation re+uire' fro5 the 9usto5er. '(e minimum ressure relievin& ca aci#3se# ressure lus accumula#ion ressure4 mus# be develo ed a# a ressure no# e ceedin& aressure e)uivalen# #o #(e corroded avera&e ei&(# er uni# area o #(e #o#al loa#in& roos#ruc#ure. '(e minimum e #ernal ressure 3vacuum4 relievin& ca aci# 3se# ressure lusaccumula#ion ressure4 mus# be develo ed a# a ressure no# e ceedin& #(e roo desi&n liveload o 12.5 "bs/ # 2 32. in * 2=4. Refer to 3%0 $%$,No#es 8ink for vent si8ing.

As a minimum AP" 2000 s#a#es #(e ollo in& rules or de#erminin& ven#in& ca aci#ies:

,or em # in& a #ank su icien# ven#in& area mus# be rovided or 560 cu # o ree air er(our or eac( 100 bbl er (our ma imum em # in& ra#e.

,or illin& a #ank su icien# ven#in& area mus# be rovided or 1200 cu # o ree air er(our or eac( 100 bbl er (our ma imum illin& ra#e.

!"ecific 5aintenance instructions or ressure-vacuum relie ven#s mus# be rovided in#(e =D; manual. '(e se# oin#s o #(e ven#s mus# be con irmed b !B" a# #ime oins#alla#ion. $ee ) $ $% No#es 8ink .

-rovi'e a stilling well (ic( reduces &as disc(ar&e veloci# a# #(e roduc# sur ace #o reduce

#(e likeli(ood o en#rained li)uid ar#icles &oin& #(rou&( #(e ven#. $ee !t'. Dwgs #%00$* 0an' #%00$* .

%.3 *ui'e Device: A &uide ole reven#s #(e loa#in& roo rom ro#a#in& in #(e #ank durin&use and (ile res#in& on i#s su or#s. $ee 3%0 $ No#es 8ink or de#ails.

%. 0 Rolling a''er an' Rolling a''er Runway: $ee 3%0#$#No#es 8ink . A rollin& ladderis used #o rovide access #o #(e roo rom #(e &a&er s la# orm. ,urnis( #(e deck run a or#(e rollin& ladder. $ee 3%0#$#No#es 8ink . ;. /ote: " #(e rollin& ladder run a assesover a c(an&e in slo e o #(e #o deck %n&ineerin&-Assi&ned s(all de#ail #(e run a an&lebend.

"# is acce #able #o omi# #(e rollin& ladder i #(e Purc(aser s eci ies bu# #(e loa#in& roo

canno# be cer#i ied as mee#in& AP" $#andard 650.%. !eal 6etween Roof an' 4ank !hell: $ee 3%0( No#es 8ink .

Nominal rim s ace is > . $#andard roo s over 20 diame#er re)uire a 12 rim s ace.*o ever i #(e #ank (ei&(# e ceeds 56 #anks over 2


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%. # Ri5s: $ee 3 0,$0$%0 No#es 8ink or rim la#e con i&ura#ion.

%. ( Reinforcing 6ar: Rein orcin& bars mus# ene#ra#e #(e bulk(eads and be elded inaccordance i#( Figure #.%b. eldin& around #(e end o #(e bar mus# be on #(e same sideo #(e bulk(ead as #(e bulk(ead #o bo##om deck eld.

'(e roo ei&(#s lis#ed in #(e ollo in& #ables are #(eore#ical and include bo#( decks ra #ersra #er cli s. bulk(eads rims rein orcin& bars &a&er s la# orm emer&enc drains and all i#ems in%. and %.# #(rou&( %. 0. '(e ei&(#s do no# include #(e seal or #(e rimar drains. ei&(#&iven is or #(e ma imum diame#er.

Nominal rim s ace is measured rom #(e cen#erline o #(e s(ell la#e #o #(e ou#side o #(e ou#errim la#e. '(is dimension is used or desi&n and de#ails o #(e loa#in& roo . %n&ineerin&-

Assi&ned ill s(o #(e ac#ual s ace dimension be# een #(e inside o #(e bo##om s(ell rin& and#(e ou#side o #(e ou#er rim la#e on #(e con#rac# dra in&s. '(is dimension ill be used b!ons#ruc#ion-Assi&ned.

+esi&ns or bo#( sin&le and reverse slo es can accommoda#e u #o 1/16 corrosion allo ance on#(e bo##om deck and ou#er rim i#(ou# an o#(er de#ail c(an&es.

%n&lis( #ables in #(is s#andard can be direc#l conver#ed #o me#ric usin& ei#(er .> mm or 5.0 mmla#e.

#. !ingle !lo"e Roof Designs: 4able #. b &ives s#andard desi&ns or sin&le slo e roo sin #anks 50 diame#er and less. 4able #. c &ives desi&ns or sin&le slo e roo s in #anks over50 #(rou&( 190 diame#er.

4able #. a $ 9o'e for Rafter !ections

etter Rafter !ection !ection Mo'ulusin #;

Metric .2 . > @PN 1 0% !< 9.> 6.0> @PN 160C !> 11.5 >.1 @PN 1>0
http://notes///852563A600577DE7/2416762E59280CC9852563C4006A702C/9878E901EEA3F73A8625637F006AAEEFhttp://notes///852563A600577DE7/2416762E59280CC9852563C4006A702C/9878E901EEA3F73A8625637F006AAEEF


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4able #. b $ Re+uire5ents for !ingle !lo"e Double Deck Floating Roof => ,0? Dia

'ank3 #4

+ia No. o Bulk(eads

Ra #ers $u or#s No. o+eck

;an(oles Rooei&(#

=ver "ncl No. $i7e No. Radius =u#er Ba "nner Ba 3ki s4- 25 > - - 0. 1 1 .6

25 0 > > A 0. 1 1>. > B 0. 1 2 .55 0 > 16 B 0.65R > 1 29.60 5 > 16 ! 0.60R > 1 5.>5 50 > 16 + 0.60R > 1 2.>

Figure #. b $ 4y"ical !ection 4hrough !ingle !lo"e Double Deck Floating Roof => ,0? Dia


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Figure #. c $ 4y"ical !ection 4hrough !ingle !lo"e Double Deck Floating Roof ,0? = Dia.=> 30?

#.% Reverse !lo"e Roof Designs: 4able #.%a &ives s#andard desi&ns or reverse slo eroo s in #anks over 190 #(rou&( 00 diame#er.

Figure #.%a $ 4y"ical !ection 4hrough Reverse !lo"e Double Deck Floating Roof 30? =Dia => (00?


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4able #.%a $ Re+uire5ents for Reverse !lo"e Double Deck Floating Roofs 30? = Dia =>(00?

'ank3 #4

+ia No.o

=u# rrim

8oRim

=u# r Rim N A

NB N Rein Bar

No. Ra #ers er Ba=u#er Ba #o "nner Ba

No. $u or#s er Ba=u#er Ba #o !en#er Ba

Bulk-

*# *# '(k $i7e Ra #er $i7e No. +eck ;an(oles

=ver "ncl (ead 3in4 3in4 3in4 3$ee 'able .1a or !ode4 ki s

190 195 25 6 19 /16 2 1 5 / 0%

65%

5+

2>+

2525

206

15

9 %

2525

216

165

11 %

6%

>%

2>%

2626

21>%

6>%

>%

2>%

2%

2>%

2%

2>2>

22>

26

1 < C 96C % 2929 2< 1>6 1 0%

65% +

2>+

00

25>

206

15

11 %

6% %

2>%

00

26>

21%

2>%

11

26>

21>%

6>%

>%

2>%

22

2

22%

6>%

>%

2>%

22

2

22%

2>9

2%

55

19

26>

215 6 6 19 /16 1 < 6 E 1 10>%

12%

10%

>%

6>%

>%

2>%

66

110

26>

21%

>>%

6>%

>%

2>%

%

>%

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%

2>%

>> 10

2>>

22> 10

2>9

26

12 6 1 12%

1%

12%

10%

>%

6>%

>%

2>%

11

611

110

26>

21%

10>%

>>%

6>%

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11

C

12>%

10>%

>>%

6>%

>%

2>%

22

C

>>%

6>%

>%

2>%

>11

10

222%

>12

10

2>92 612 .5 5/16 2 > > 1 1 2C

156C

1 2C

112C

92C

%

2>%

912

10

2>92 612 .5 /> 2 > < 1 1 5

C

156

C

1 6

C

116

C

92

C

%

5

5

91

2

1

0

2992 61 /> 2 > < 1 1 5C

160C

1 6C

116C

96C

%

55

012

11

2992 61 1 1 >%

16%

1%

12%

10%

>%

6>%

>%

2>%

66

112

611

110

26>21%

12>%

10>%

>>%

6>%

>%

2>%

66

21 %

>>%

6>%

>%

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%

6>%

>%

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>>

1 >11

210

2 225 > 2 19 /> 5 2 9 < 1 1C

1%

>%

2>%

>>

1 >12

10

2>92 5 2 9 < 1 1 92 612 .5 /> 5 2 9 > 1 150

C

192 61 .5 /> 5 9 > 1 150C

1>0C

160C

1 6C

116C

92C

%

5050

51 012

10

2992 61

Documents

Double Deck Floating Roof