Floating Roof Tanks - Different Aspects

Typ ype es o f Tan k s FLOATING ROOF TANKS IFR

CONE ROO ROOF F TANK TANKS S (CR)

DOME ROOF TANK

EFR

(a) Ad Adva van n tage of Fl Fl oati oatin n g Ro of Ta Tank nks s

CONE ROOF TANKS

FLOATING ROOF TANKS

MINIMIZING VAPOR SPACE: (a) ELIMINATES FILLING LOSS

CONE ROOF TANKS

FLOATING ROOF TANK

MINIMIZING MINIMIZ ING VAPOR SPA SPA CE: (b (b)) REDUCE REDUCES S BRE B REA A THIN THING G LOSS L OSS

CONE ROOF TANKS

FLOATING ROOF TANKS

MINIMIZING VAPOR SPACE: MINIMIZING SPA CE: (c (c)) PROVIDES EFFECTIVE EFFECTIVE FIRE PROTECTION AND LIGHTING SAFETY, IT ALSO INHIBITS ROOF AND

(b ) Typ ype e o f Fl o at i n g Ro of  There are a variety of deck options that may be exercised depending on the service conditions of the stored product.

• • •

Single Deck Pan Type Single Deck pontoon Type Double Deck

Selection of a specific type of roof and tank depends on the intended service conditions, such as the petroleum liquid being store stored, d, its vap vapor or press pressure ure and and corro corrosive sive nature nature,, and the anticipated weather and loading conditions.

Genera nerall Ind Indus ustr try y Trends Trends in i n selecti selection on

• Double deck deck floating floating roofs for large large diameter diameter tanks tanks above 60 m dia. for  crude oil service (to conserve lighter lig hter end products) or otherwise and very small diameter tanks less than 15m • Single deck deck floating floating roof tanks for most intermed intermediate iate range range tank diameters diameters • Inter Internal nal floating floating roof tanks for volatile, volatile, highly highly inflammable inflammable or value added added Products Prod ucts – based on economics economics of adva advantage ntages s vs costs On the the aforesa aforesaid id guidelines, a thumb rule classification of roof selection for various service conditions cond itions may be be made. A final selection selection would would require require a more deta detailed iled investigation of process conditions during tank service and relative vapor  loss advantages gained by the use of various deck options.

SINGLE SIN GLE DEC DECK K (PONT (PONTOON OON TYPE TYPE)) EXT EXTERNAL ERNAL FLOATIN FLOA TING G ROO ROOF F TANK TANKS S • Av Availa ailable ble in sta standa ndard rd sizes sizes fro from m 15 – 91 91.5 .5 m diame diameter  ter  • Prov Provides ides a cost effective effective solution, solution, compared compared to the double deck, deck, except except in the larger and very small sizes • Great Greater er water water carryi carrying ng capacity capacity while while afloat • Pron Prone e to weldsea weldseam m fatigue cracki cracking ng from extend extended ed exposu exposure re to to high high wind wind conditions • Suffici Sufficient ent pontoon pontoon volume volume to keep deck deck afloat with with any two pontoon pontoon compartments punctured • Ponto Pontoon on area varies varies from 35% 35% on small diameter diameter roofs roofs to 20% on on large diameter roofs • Ponto Pontoon on underside underside slopes slopes upward toward toward centre of roof to hold temperatu temperature re gene ge nerat rated ed con conden densible sible vap vapors ors

SINGLE SIN GLE DEC DECK K EXTE EXTERNA RNAL L FLOA FLOATIN TING G ROO ROOF F TA TANKS NKS (EFR (EFR))

Roli Roling ng ladd ladder  er 

Curb Angle

(typ)

Rim

Shell

Deck Plate

Sin ingle gle D ck P

to

T

Flo ti

Pontoon

R

f T nk

DOUBL DO UBLE E DE DECK CK EXT EXTER ERNAL NAL FL FL OATIN OATING G RO ROOF OF TANK TANKS S • Av Availa ailable ble in in stand standard ard siz sizes es from from 9 – 12 122 2 m dia diamete meter  r  • Most efficien efficientt solution, double double deck provides provides good insulation insulation over entire entire liquid surface, most stable and maintenance free option for larger sizes • Limited water water carrying carrying capacity capacity while afloat, afloat, water water allowed allowed to pass through deck • Reduc Reduces es impact of high winds winds on product, product, stable performanc performance e of deck under  such conditions • Emerge Emergency ncy drain drains s provided provided to accommo accommodate date 10” of rainfall rainfall in 24 hours hours • Roof designed designed to float float directly on on product, product, and stay afloat with with any two compartments punctured. Deck flexibility allows temperature tem perature generated condensible cond ensible vapor to to be contained contained under under center center of of deck

DOUB DOU B L E DECK EXTE EXTERNAL RNAL FLOA FLOATIN TING G RO ROOF OF TANK TANKS S (FR (FR))

DOUB DOU B L E DECK INTE INTERNA RNAL L FLOA FLOATIN TING G ROO ROOF F TANK TANKS S (IF (IFR) R) • Prov Provides ides additional additional prote protection ction against against wind and rain • Combin Combines es the all-weathe all-weatherr performance performance of a cone roof roof tank with with the evaporatio evap oration n saving and fire protec protection tion qualities qualities of a floating roof tank • Maxi Maximum mum protection protection against against expos exposure ure or rim rim fires • Floatin Floating g roof simultaneously simultaneously combats combats corrosion corrosion and product product deteriorati deterioration on • No draina drainage ge system system require required d – this eliminate eliminates s maintenan maintenance ce of of this item and and floating roof may be operated to lower levels • In lieu of pan type constructi construction, on, special special pontoon type type decks can be provided provided for more positive floatation and increased stability. • Shell Shell/Roof /Roof vents vents provided for venting venting air-vapo air-vaporr mixture between between the floating deck and fixed roof during product pump in

DOUB DOU B L E DECK INTE INTERNAL RNAL FL FL OATING ROO ROOF F TANK TANKS S (IF (IFR) R)

DOUBLE DECK EXTERNAL FLOATING ROOF TANK CENTER DRAIN PROFILE

DOUBLE DECK EXTERNAL FLOATING ROOF TANK REVERSE REV ERSE SLOPE PROFILE PROFIL E

Roof Drain

Pipe Support

Roof Drain

PARTS OF ADJUSTABLE / FIXED PIPE SUPPORT

DECK DE CK MANWAY • Deck Deck ma manw nway ay is us use e to en ente terr the the ta tank nk bo bott ttom om fro from m top top of de deck ck by using internal ladder and also use as vent. during duri ng mainta maintanance nance when tank is is empty empty..

PONTOO PON TOON N MANWA MA NWAY Y • Pont Ponto oon Manw nway ay is use use du duri ring ng hy hydr drot otes estt of pon ponto toon on.. W ater is inlet from pontoon manway. • General allly size of of Po Ponto too on Ma Manway is 20” 20” NB. • Eac Each h comp compart artme ment nt one one & for big tank tw two o requ require ired. d. • Po Ponto ntoon on ma manw nway ay is us use e to to exce excess ss in in pon ponto toon on for wel eldi ding ng of  radiall & circumfer radia circumferenc encial ial bulkh bulkhead ead to bottom bottom deck deck also.

PA RTS OF DECK MA MA NW NWA Y

PA RT RTS OF PONTOON MA NWA Y

 A n Ex  An Exam amp p l e of of Deck L ayou youtt of of Floating Roof Tank Ta nk Size i s 92m ID x 20M HT. EFR Ta Tank nk f or Crud rude e Oil Oil Sto torage rage

PARTS OF CONE ROOF TANKS

Dome Roof Knuckle Profile

Looking down on Knuckl Knuckle e