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AAluminum, used formajor aboveground-storage tank (AST)

components, has advantages

and disadvantages whencompared to the conventionalsteel materials of construc-tion.

For fixed-roof tanks, refin-ers can save money and gainimproved quality if they con-sider the advantages of alu-minum over steel.

This article is the first of atwo-part series that discussesthe use of aluminum structur-al components for ASTs. Thefirst article presents a compar-ison of covered tanks vs. un-

covered tanks (tanks with afloating roof but no fixed-roof) as well as a comparisonof aluminum-dome roofs(ADRs) vs. steel-cone roofs(SCRs). The second articlecompares various types ofaluminum and steel internal-floating roofs.

For large ASTs, fixed roofsshould be aluminum becausethe roof-support columns canbe eliminated when using alu-minum domes (Fig. 1). LargeSCRs require columns. Alu-

minum domes maximize tankcapacity, reduce coating costs,and have fire-safety advan-tages.

For internal-floating roofs,aluminum and steel each hasits own merits. Instead of justbid prices, tank managers andoperators should consider thelong-term operational, safety,environmental, and economicissues of aluminum and steelcomponents in ASTs.

Although API 650 definesa minimum standard of qual-

ity, in some cases, when safe-

ty and total cost of ownershipare considered, the standardmay not be adequate for de-sired long-term performance.

Covered vs. uncoveredtanks

An AST that includes afloating roof and is coveredby a fixed roof is consideredan internal-floating roof tank(IFRT). An existing external-floating roof tank (EFRT) canbe converted to a covered

IFRT by retrofitting it with afixed roof or cover.

Although the EFRT mayhave a lower initial cost thanthe IFRT, it may not have thelowest total ownership costwhen long-term operatingcosts, maintenance costs, andpotential risks are considered.The factors which favor build-ing or retrofitting EFRTs withfixed roofs are incident pre-vention, environmental pro-tection, safety, and reducedlong-term maintenance and

operating costs.

Table 1 summarizes theconsiderations for the use ofcovered tanks (IFRTs) vs. un-covered tanks (EFRTs).

Overloading external-floating roofs

External-floating roofs arevulnerable to overloading.The fixed roof eliminates theintrusion of rainwater, snow,ice, and dirt into the tank.

In EFRTs, precipitation cansink the floating roofs duringheavy rainfalls or prolonged

winter storms. Historically,several external-floating roofssink each year in the U.S. dur-ing the winter or as a result ofextreme rainfall events. Thisnumber may be underesti-mated because these incidentsare not required to be report-ed through any public chan-nels.

Snow, ice, dirt, and debrisaccumulation can render thedrains inoperable, resulting inoverloading. Overloading canresult when drain systems

freeze close or when drain ca-

pacities are inadequate.In addition, heavy snow-

fall can result in an unbal-anced load condition if the

snow collects on the wind-ward and shaded surfaces. Inthe Middle East, where rain-water, snow, and ice are not aconcern, some users requireIFRTs to avoid accumulationsof windblown sand.

External-floating roofs areespecially vulnerable to over-loading when the productlevel is low or while the float-ing roof is landed on its sup-ports. There are several rea-sons for this:

Per API 650-Appendix

C.3.4, the design buoyancy isbased on supporting 10 in. ofrainwater (or 52 psf); howev-er, the supports are only de-signed to support 25 psf, perAPI 650-Appendix C.3.10.2.

When the roof is float-ing at a low elevation, thehead pressure forcing rainwa-ter through the drains is re-duced. This head reductionincreases the amount andweight of water on the deckduring rainfall.

In an annular-pontoon

floating roof (flat-centerdeck), the center deck is high-ly flexible and will rise whenvapors evaporate as the deckis heated by solar energy. Thedeck also deflects downwardat the center as it is loadedwith water. When the roof isfloating near the bottom,loaded with water and sag-ging at the center, the centerdeck supports can contact thebottom and fail as a result ofbeing overloaded. The float-ing roof supports have also

been known to puncture the

FOCUS: REFINING

ALUMINUM TANK COMPONENTS1

Aluminum a good alternativeto steel for fixed-roof tanks

Philip E. Myers Chevron Products Co. San Ramon, Calif.George L. Morovich Tank & Environmental Technologies Inc. The Woodlands, Tex.

Earl J. Crochet Plantation Pipe Line Co. Atlanta

Aluminum domes maximize usable tank capacity, avoidcoating costs, and avoid column problems. Photo courtesyof Temcor (Fig. 1).

Reprinted with revisions to format, from the May 18, 1998 edition of OIL & GAS JOURNALCopyright 1998 by PennWell Corporation

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bottom, resulting in seriousleaks.

The drain sizes of the ex-ternal-floating roofs identifiedin API 650-Appendix C3.8,are minimal. The purchaser

should understand and iden-tify the drain requirements foreach location, based on antici-pated rainfall.

Water intrusionThe covered tank mini-

mizes rainwater entry into thetank.

Rainwater can intrude intothe tank stock by seeping pastthe seals. Water will mix withor leach out certain additivesor components, which maycompromise product quality.

In addition, contaminatedwater bottoms require thelong-term cost of collectionand disposal as a hazardouswaste.

Another problem associat-ed with water entry into thetank has to do with methyltertiary butyl ether (MTBE)and other ether or alcohol-based additives, which arecommonly used as a gasolineadditive to meet requirementsof the Clean Air Act.

Because MTBE and alcohol

are preferentially soluble inwater, remediation is morecomplex for them than for hy-drocarbons; therefore, it is im-portant to minimize any in-troduction of water into atank storing oxygenated gaso-line.

Eliminationof EFRT drains

By covering a tank, theneed for an EFRT-rainwaterdrain is eliminated. The re-moval of the drain avoids the

risk of drain-line failure, re-duces the initial tank equip-ment cost, and results in sig-nificant long-term operationaland maintenance savings. Fig.2 shows how the drain is at-tached to the EFRT.

The drain removal is envi-ronmentally desirable be-cause the potential for a majorspill or release as a result of aroof-drain failure is eliminat-ed. A substantial spill mayoccur if the roof drain rup-tures and the valve on the

roof drain has been left open.

Many companies requireEFRT-drain valves to be keptclosed. This policy, however,increases the risk of overload-ing the floating roof because itrequires manual interventionto drain the floating roof dur-

ing rainfall. Some companieshave installed hydrocarbon-sensing valves and other de-tection devices on the roof-drain outlets; however, thesedevices have not proven effec-tive to prevent the release ofhydrocarbons through a dam-aged roof drain line under allconditions.

In the long-term, avoid-ance of maintenance costsstems from eliminating themanual-drain operation.Maintenance can be annual

cold-climate protection or

eventual drain-line replace-ment. To prevent drain-sys-tem damage during pro-longed winter conditions, ex-ternal-floating roof drains areoften filled with antifreeze,which introduces an addition-

al hazardous waste handlingand treatment cost.

Increased usabletank capacity

For covered-floating rooftanks (converted from anEFRT) and for IFRTs, federalregulations do not require asecondary seal. The elimina-tion of the secondary seal re-duces the initial tank equip-ment cost and associatedlong-term maintenance andinspection costs. Perhaps

most important, it increases

the usable capacity (or work-ing volume) of the tank.

Because only a single liq-uid-mounted primary seal isrequired for an IFRT, floatingroofs can be operated at ahigher level, closer to thefixed roof without interfer-ence from the secondary seal.

The capacity savings from

eliminating the EFRT weath-ershield-type secondary sealcan be in the range of 24-36in.; however, eliminating asecondary seal from an inter-nal-floating roof will saveonly 8-12 in. For new con-struction, the lower designloading of API 650-AppendixH (Internal Floating Roof),will further reduce outer rim-profile clearance require-ments by an additional 10-24in. depending on the type ofinternal-floating roof.

CorrosionExternal-floating roofs cor-

rode and must be maintainedby initial and periodic recoat-ing. Costs for recoating oldtanks with lead-based paintscan be significant. By coveringthe tank, the need to coat thefloating roof is eliminated.Even if the external-floatingroof is due for a coating re-moval and paint job, it is notnecessary if the tank is cov-ered.

The severity of internal-

FOCUS: REFINING

Covered tanks Uncovered tanks

Eliminates rainwater entry(Environmental loading) Rainwater can:

Sink floating roofs if roofs are not drained or if drainplugs Add to water bottoms which may increasedisposal/treatment costs or cause product contamination Accelerate bottom corrosionSnow and freezing can cause floating-roof mechanicalfailures or sinking

Eliminates roof drain Requires roof drain which: Uses more vertical space to allow sufficient hydraulichead Is a potential for serious external spills if the drain isnot properly operated Increases the potential for liquid on roof if roof drain isdamaged

Requires only a primary seal* Requires primary plus secondary seal which: Requires secondary seal inspection and maintenance Requires more vertical spacing to accommodate sec-ondary seal

Seal fires rare Seal fires relatively common

* Although EPA 40 CFR 60 - U.S. EPA New Source Performance Standards does not require a secondary sealfor IFRTs, local air quality management districts (such as the Baaqmd in California) have stricter requirements In-cidents of internal floating roof fires are far more rare than external floating roof fires; however, IFRT fires havebeen extremely serious.

COVERED VS. UNCOVERED TANKS

Table 1

OGJ

Fig. 2

EFRTDRAIN

Drain hose

RainwaterPlugging

Valve must be open

to drain rainwater

Secondaryseal

Water layer

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shell corrosion is normally re-duced by covering the tank.For tanks which are fully coat-ed on the internal shell, thelife of the coating will be in-creased as a result of the re-

duced weather effects.

Safety and securityFixed-aluminum dome

and steel roofs are less likelythan EFRTs to cause fire andaccess problems.

Because an internal-float-ing roof is within a closedconductive structure, theFaraday Cage Effect, whichisolates the interior from theeffects of external electricalevents such as lightningstrikes or static charges, re-

duces the risk of fire. Even di-

rect lightning strikes will notcause sparks to dischargefrom the floating roof to thetank shell.

Fires or explosions involv-ing internal-floating roof fires

are hundreds of times lesslikely than those involvinguncovered EFRTs. ExistingEFRTs have also been coveredsimply as a result of theirproximity to an ignitionsource (such as a flare stack).Despite increased potential,rim fires on EFRTs are usuallyquickly extinguished.

A fixed roof controls ac-cess to the hazardous or con-fined space environment inthe tank. The U.S. Occupa-tional Safety and Health Ad-

ministration (OSHA) requires

that each facility designatethose areas that are confinedspaces, and entry must meetall requirements under OSHA29 CFR 1910.146. Typically,for petroleum-storage tanks,

the space within the shell ofan EFRT is considered a con-fined space if the roof is below5 ft of the rim. For an IFRT,however, any space withinthe shell or under the fixedroof is always considered aconfined space.

Many EFRTs in remoteareas have been covered dueto concerns of unauthorizedaccess. In one case, childrenwere found riding their bicy-cles on the deck of a 200-ft di-ameter EFRT slated for gaso-

line additive (MTBE) service;

spent bottle rockets were alsofound on that same deck.

In the 1980s, the U.S. AirForce Strategic Air Commandbegan a program to cover ex-isting EFRTs, primarily to

eliminate water problemswith jet fuel and antifreezeadditives. A side benefit ofcovers was to conceal base-fuel inventory levels from aer-ial surveillance.

Steel-cone roofs vs.aluminum-dome roofs

Clear-span ADR tankshave more advantages thando column-supported SCRtanks. Table 2 comparesADRs and SCRs.

The ADR is usually the

FOCUS: REFINING

Steel cone Aluminum dome Additional comments

Corrosion Columns increase corrosion under No columns Corrosion will be more severe if a water-bottoms layer iscolumn bases. Poor coatings preparation present under the column bases. This is common for fin-

and application can aggravate corrosion. ished-fuel tanks.

Inspection Columns make inspection under No columns Inspection under column bases is typically not done due tocolumn bases difficult and often the difficulty of lifting the column and roof to visually inspectoverlooked. under the column bases.

Lin ings and coat ings Columns tend to cause l in ing No columns Column bases rest f lat on the tank bottom and are noterosion and poor lining application at attached.Because of settlement, thermal expansion, andcolumn bases due to movement and small movements, the column base wears any coating onsharp edges. the bottom. It is also very difficult to properly apply coatings

in areas such as around column bases.

Fire hazards Columns trap hydrocarbons which are No columns There have been many cases of injuries and fireshazards when hotwork occurs during associated with liquid hydrocarbons trapped in roofmaintenance. columns. The problem is more serious with pipe columns

than built-up members. API 2015 has a complete discus-sion of this topic.

Maintenance hazard Columns often have to be jacked up No columns The jacking process is a dangerous operation in which

to install double bottoms or to do improper procedures cause roof collapse as well asother work. injuries.

Emissions Columns represent points of emissions. No columns The EPA program, Tanks 3.1, can be used to determinethe effect of emissions from fixed-steel roof tanks vs.aluminum-dome roofs. This program is available to thepublic on the internet.

Floating-roof binding Columns can bind on the floating roof No columns.causing liquid to enter the roof or, in theworst case, to sink it.

Frangible roof Frangible roof is possible. This is a Frangible roof not Although the frangible roof specified by API 650 is aclear advantage. possible. valuable explosion and overpressure protection, it is not

known how the aluminum dome will perform under similaroverpressure situations.

Cost Typically, steel cone roofs have a Typically, aluminum- Proper cost analyses by competent personnel are requiredlower initial cost. dome roofs have a to examine the true and total costs of ownership.

higher initial cost. If

coating costs areincluded or if life spanis considered thenaluminum often givesa better total cost ofownership.

*Comparison does not apply to self-supported steel-roof tanks (usually 20 ft in diameter or smaller). Larger tanks have more columns.

STEEL CONE VS. ALUMINUM DOME CHARACTERISTICS*

Table 2

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most favorable option for theretrofit of an existing EFRTwith a new fixed roof. For

new tank construction, or re-placement of an existing coneroof, an evaluation shouldconsider the initial bid priceas well as other fundamentalvariables:

Operating capacity sav-ings

Initial coating cost andlong term maintenance

The elimination ofcolumns and their relatedproblems: emissions, penetra-tion seal, bottom corrosion,maintenance obstruction, set-

tlement, and incident riskcosts.S t ee l , s e lf - su p p or t ed

dome-roof tanks and small-diameter tanks with self-sup-ported fixed roofs are exclud-ed from this evaluation; theyshare, however, many of thebenefits of ADR tanks.

SimilaritiesFunctionally, the roles of

the ADRs and the SCRs aresimilar:

Both types protect the

floating roof from environ-mental loading.

Both types minimizedirt and water entry into thetank.

Both types eliminate theintrusion of rainwater into thetank; however, the quality ofthe aluminum-dome weather-tight design will vary by man-ufacturer. It is critical to spec-ify a proven-ADR designwhich is leaktight.

Both types reduceweather-related corrosion on

the internal-shell surfaces.

Both types eliminate thewind-related component oftank emissions.

Both types improve fireprevention, improve safety,and enhance security.

Cost effectivenessTechnically, the ADRs and

SCRs have different require-ments. When retrofitting anexisting EFRT with a newfixed roof, the conversion toan ADR tank is usually themost cost effective, regardlessof tank size. This conversiondoes not require removalfrom service, tank cleaning, or

extensive downtime for hot-work.The aluminum dome is a

bolted structure that can beassembled on the tank withno hotwork. Steel roofs re-quire hotwork because theyare field welded; therefore,the hazards increase for steelconstruction.

Today, new SCR construc-tion should minimize thenumber of SCR-supportcolumns to avoid penetra-tions of the internal floating

roof and their related initialcosts, increased emissions,and column-seal replacementcosts.

Without considering otherinitial and long-term cost fac-tors (listed below), the alu-minum dome usually be-comes cost effective for tankdiameters of 40 m or more,the diameter for which multi-ple rings of columns would berequired for an SCR. The alu-minum-dome roof is cost ef-fective for tanks larger than 20

m when compared to a steel-

dome roof and larger than 10m if internal coatings areneeded for steel.

CapacityThe capacity of an SCR is

reduced because the cone-roof support structure (in-cluding roof rafter-to-shell at-tachment gussets) extends 12-18 in. below the top of thetank shell, and the floating-roof seal may run into thefixed-steel roof. Although thetank shell could be extendedupward, this is typically notpractical or cost effective for aproject to cover an EFRT. TheADR tank does not usually re-strict capacity because the at-tachment of external framing

permits full travel of the sealto the top of the tank shell.Analyses should always be

performed to confirm clear-ance with other deck obstruc-tions (e.g., foam dams andpressure/vacuum vent).Larger-diameter domes havea steep rise at the periphery,which helps avoid interior-deck obstructions. For addi-tional clearance, the alu-minum dome can be installedwith a skirt, which effectivelyraises its base elevation.

CoatingsWhen comparing the dif-

ferences between steel andaluminum, it is important toconsider the rather substantialcosts of surface preparationand coating. Aluminumdomes are typically not coat-ed, whereas steel roofs are al-ways coated externally andoften coated internally in cor-rosive environments.

ADRs are justified fortanks with diameters as small

as 10 m for tanks which re-quire internal coatings. Thisconclusion is based on consid-eration of the coating cost, thespecial construction-detail re-quirements, the internal seal-welding requirement, and theextensive preparation re-quired for an effective inter-nal coating. In addition, coat-ings have maintenance costsand recoating charges as a re-sult of normal wear.

Beyond the initial roofcoating cost on an SCR, there

is the future maintenance. Of

FOCUS: REFINING

OGJ

Fig. 3

GEODESIC DOME VS. CONE ROOF

Source: OGJ, July 10, 1989, p. 90.

Dome can beeasily elevated

to increase tank

capacity. Floating roof

Areas under

column supports

are prone to

corrosion and

hard to inspect.

Deck

penetrations

Columns

Geodesic dome Cone roof

all the externally coated sur-faces on a typical tank, thecone-roof coating will fail firstas a result of horizontal expo-sure to sunlight and pondingof rainwater. These factors re-

sult in rust streaks that rundown the tank shell and cre-ate a cosmetic problem.

The use of an ADR extendsthe time interval betweentank-shell recoating and elim-inates the cost of recoating theroof-surface area.

Steel roofs often have un-coated internal surfaces.These roofs can produce tonsof corrosion products thateventually delaminate fromthe underside of the fixed roofand collect on the bottom of a

tank. In one case, an estimated70 tons of corrosion productswere removed from the bot-tom of a 280 ft-diameter SCRtank in crude oil service.

Had an internal-floatingroof been used, the exposureof the fixed roof to corrosive-sulfur compounds wouldhave been minimized. Pre-ventive maintenance, howev-er, would still have been re-quired to remove some corro-sion products from the deck.The ADR would not have

generated corrosion products.

EmissionsThe emission of organic or

hazardous vapors from anADR is lower than that of asimilar SCR. Unlike the coneroof, the dome is a free-spanstructure. The SCR tank hascolumns that extend from thefixed roof, through the float-ing roof, and to the tank bot-tom. The SCR has one or morecolumn penetrations fromwhich emissions escape to the

atmosphere. The use of analuminum dome reduces thetotal facilities emissions in-ventory by avoiding the emis-sion factors for column pene-trations.

Fig. 3 illustrates the differ-ences between the ADR andSCR tanks.

Chapter 19, EvaporativeLoss Measurement, of the APIManual of Petroleum Mea-surement Standards providesa basis for the EPA emissionscalculation program. Al-

though not currently part of

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the emission calculation for-mula, the API Committee onPetroleum Measurement isconsidering better definingthe variables that influencebulk and surface liquid tem-

peratures to improve accura-cy. For example, althoughbulk temperature is currentlybased on ambient air condi-tions, the method of deliveryand turnover rates are moreinfluential in determining thebulk temperature.

Currently, there is only ageneral paint factor to ad-just bulk temperature for roofvariables. External-floatingroofs exposed to direct sun-light should have higher sur-face-liquid, shell-surface, and

deck-fitting temperatures thancovered-floating roofs. Cur-rent bulk-temperature calcula-tions, however, do not includethese solar-radiation effects.

Although not currentlyconsidered in the emissionscalculation, the type of mater-ial used in the tank shouldalso be considered. Becausealuminum has higher reflec-tive and lower emissive prop-erties than steel, emission cal-culations should include thefollowing variables:

Adjustment of liquid-surface temperature to reflectthe impact of heated-shell andEFRT surfaces.

Addition of solar impactand material variables to re-flect reduced internal-surfacetemperatures by either a steelor aluminum fixed roof.

Addition of solar impactand material variables to re-flect reduced surface-liquidtemperatures by using vari-ous types of aluminum inter-nal floating roofs.

Corrosion causedby columns

Roof-support columns in-crease the potential for tank-

bottom corrosion and roofcorrosion.

API standards do notallow columns to be attachedto the tank bottom so that thetank bottom can settle with-

out distorting the roof. Themovement of the column baseon the tank bottom erodesany coating on the tank bot-tom and creates conditionsconducive to crevice corro-sion.

Corrosion damage that oc-curs near or under the columnbases is rarely inspected (evenduring formal API 653 inter-nal inspections) because thebase plate covers the corro-sion damage. Column guidesand base plates, welded to the

tank bottom, make coating-surface preparation and ap-plication difficult, which in-creases the potential for corro-sion attack.

Because there is a higherprobability of tank-bottomleaks as a result of corrosionin SCR tanks, the potential forresulting environmental cont-amination increases.

Also, if the SCR supportcolumns vertically settle, thecone roof surface plates willdeflect downward and pond

water (accelerating corro-sion). A clear-span aluminumdome is supported by thetank shell, and uniform shellsettlement can be facilitatedby the use of a concrete ring-wall foundation design.

More column problemsColumns can cause prob-

lems if they are out-of plumb,trap hydrocarbons, or are im-properly jacked during main-tenance.

Columns which are out-of-

plumb with each other andthe tank shell can cause thecolumn-penetration seals towear. In severe cases, floatingroofs have hung up on

columns as the product levelrose.

Closed-shaped columns,such as pipe columns, canhold trapped hydrocarbonseven if they are designed to be

self draining. Many fires andexplosions have been initiatedby trapped hydrocarbons inroof columns during internal-tank work.

Tank columns are oftenjacked up when new tank bot-toms are being installed orduring maintenance.Columns and jacking struc-tures can collapse if improp-erly jacked. The aluminumdome, because it has nocolumns, is not affected by in-terior-bottom settlement and

offers no obstruction to bot-tom inspection or mainte-nance.

Roof frangibilityAPI 650 provides rules for

designing a frangible roof fornew CRTs. If a tank is inter-nally overpressurized, a fran-gible roof will fail at the roof-to-shell joint and vent the ex-cess pressure harmlessly tothe atmosphere.

In some instances, theshell-to-bottom joint has failed

while overpressuring or over-filling tanks without frangibleroofs. This failure causes thetank to rocket upward,spilling flammable contents orreleasing liquids. Frangibleroof failures historically havenot released liquid and haveresulted only in relativelyminor damage to the tank.

API 650-Appendix G,which covers the design andconstruction of ADR tanks,states that the roof-to-shelljoint is not considered frangi-

ble. Certainly, the structuralattachments are not designedto be frangible.

For all reported ADR-over-pressurization incidents to

date (less than six), however,the peripheral flashing has be-haved as if it were a frangiblecomponent. Even on ADRtanks less than 40 ft in diame-ter, in which frangible joints

are not considered reliable forSCR tanks, the flashing hasbehaved as a frangible com-ponent.

The vent area of the alu-minum-dome flashing shouldexceed the vent area requiredunder API 2000, Section2.4.3.2, which covers emer-gency and normal venting forTanks Without Weak Roof-to-Shell Attachment. There isan open API agenda item toallow the aluminum-domemanufacturer to document

the frangibility of a panelcomponent and allow thedocumented component tocontribute to the vent area asrequired by API 2000.

Component frangibility isnot the same as a frangibleroof-to-shell joint, which isdefined under API 650, Sec-tion 3.10.2.5 and API 2000,Section 2.4.3.1. Componentfrangibility is categorized sep-arately under API 2000.

Safety access

In the rare event of a firewithin an IFRT, the alu-minum dome panels providegood access to the fire surfacefor extinguishing. The panelswill melt away or allow an axto penetrate the surface. Inone incident concerning atank with an aluminum roof,during a fire started by weld-ing adjacent to a wastewaterbasin, the panels quicklymelted away allowing the fireto be promptly extinguished.

This same ability to re-

move ADR panels facilitatesaccess to the tank interior inthe event that personnel with-in the tank require emer-gency-vertical retrieval.

FOCUS: REFINING

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BibliographyAluminum Design Manual: Specifica-

tions for Aluminum Structures,the Aluminum Asssociation,Washington, D.C.

API Manual of Petroleum Measure-ment StandardsChapter 19,Evaporative Loss Measurement,American Petroleum Institute,Washington, D.C.

API Publication 2026SafeAccess/Egress Involving Float-ing Roof Tanks in Service, Amer-ican Petroleum Institute, Wash-ington, D.C.

API Standard 2000Venting Atmos-pheric and Low-Pressure StorageTanks: Nonrefrigerated and Re-frigerated, American PetroleumInstitute, Washington, D.C.

API Standard 650Welded SteelTanks for Oil Storage, NinthEdition, 1993, American Petrole-um Institute, Washington, D.C.

Barrett, A.E., Geodesic-dome tankroof cuts water contamination,vapor losses, OGJ, July 10,1989, p. 90.

EPA 40 CFR 60U.S. EPA NewSource Performance Standards

(Subpart Kb), 40 Code of Feder-al Regulations, Washington,D.C.

Myers, Philip E., Aboveground Stor-age Tanks, McGraw-Hill, NewYork, ISBN 0-07-044272-X.

OSHA 29 CFR 1910U.S. Occupa-tional Safety and Health Admin-istration, 29 Code of FederalRegulations, Washington, D.C.

Myers Morovich Crochet

THE AUTHORS

Philip E. Myers is a senior standardsengineer at Chevron Products Co. He hashad experience in process and project en-gineering in the utility, chemicals, petro-chemicals, and refining businesses. In re-cent years he has specialized in tanks andpressure-vessel technology.

Myers serves as chairman of the sub-committee for Tanks and Pressure Ves-sels for the American Petroleum Institute

(API) and is vice-chairman of ASMEsB96.1 Committee for Aluminum Tanks.He holds a BS in chemical engineer-

ing from the University of California.

George L. Morovich is president of Tank & EnvironmentalTechnologies Inc. (TETI), which he founded in 1991. TETI repre-sents a group of companies offering engineering, manufacturing,and contracting services related to industrial-liquids handling.

Morovichs primary focus is petroleum-storage tank equip-ment, emission-control systems, water storage, and wastewater-treatment equipment. He has 20 years of experience in the petro-leum-storage tank industry. Since 1989, he has served the API asa member of the subcommittee for Tanks and Pressure Vessels,of the Task Force on Metrication of Standards, and of an envi-

ronmental technical assistance group.Morovich holds a BS in geography from Sam Houston StateUniversity. He is a recipient of an environmental science grantfrom the National Science Foundation.

Earl J. Crochet is a senior engi-neer at Plantation Pipe Line Co., re-sponsible for corporate maintenance.Plantation owns a refined productspipeline with about 170 abovegroundstorage tanks.

Crochet has been involved in allaspects of aboveground storage tanks,first as an inspector, and then later asthe leader of Plantations tank in-

tegrity program.Crochet holds a BS in mechanicalengineering from Louisiana StateUniversity.

Reprints Courtesy of:

TEMCORP.O. Box 48008, Gardena, CA 90248150 W. Walnut St, Suite 150, Gardena, CA 90248(310) 523-2322 Fax: (310) 523-2380(800) 421-2263e-mail: info@temcor.comWebsite: www.temcor.com