Storage Tank Maintenance

7/25/2019 Storage Tank Maintenance

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Who and What is STI/SPFA?

Association of 186 fabricating and affiliate companiesof steel construction productsshop-fab tanks, fielderect tanks, pipe, pressure vessels and other specialfabricated products

STI members build a significant majority of shop-fabricated underground and aboveground fuelstorage tanks


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What

does Steel Tank Institute

do?

UST and AST tanktechnologies

Industry standards, RPs

Quality control of tankfabricators who buildtanks to STI specifications

Information resource TankTalk, Tank Mishaps

Certification


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Over 350,000 STI Labeled USTs


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STI AST Technologies


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Fuel Cleanliness Important

Newer Engines

Changing Fuels

Govt Regulations

Industry Practices


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Fuels

Industry

Practice

RegsRevisedStandards

New

Engines


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IncreasedNeed forStorage TankMaintenance

Result


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Fuels

IndustryPractice


NewEngines


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Air Quality

To produce cleaner burning fuel oxygenateswere added to gasoline

To produce cleaner burning fuel, sulfur wasremoved from diesel

Note changes were for Air Quality, not fuel

quality

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Gas Mileage

Automobilemanufacturersrequired to increaseoverall mileage

Regulation resultedin engine changes


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State Regulations

Some states, likeMO, regulatewater bottoms intanks

1 inch maximumwater allowed


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Fuels

Industry

Practice


New

Engines


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Clean Air & Newer Engines

Engine exhaust must be cleaner to meetEPA Clean Air regulations

Now achieve > 95% reduction in overallexhaust emission levels

Significant design modifications Fuel injection systems instead of carburetors

Reduced clearances injection system Greater timing precision required

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Clean Air & Newer Engines

Particulates can clog injectors

On-board filtration systems now include

water separators and filters to 2 microns Clear and bright just starting point

Total water of 200 mg/kg

Total particulate count 18/16/13 Filters should have Beta ratio

2 means filter removes 50% particles

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Fuels

Industry

Practice

RegsRevised

Standards

New

Engines


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Fuel Production & Distribution

US terminal capacity reduced, while fuelconsumption increased.

Therefore, more fuel moves distributed at

faster rate = less time to settle outbefore final delivery.

Industry moving to shared delivery

infrastructure, so individual companieshave less control over product.

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Biodiesel

Ethanol

ULSD

Additives

FutureFuels

New Fuels


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Changing Fuels

Changing to ULSD (Ultra Low Sulfur Diesel)significantly changed fuel:

Had a significant impact on solids formation

Peroxide formation is more of a problem

Wax precursors and solids propagators more

pronounced

What does all this mean? Generally, there maybe more particulate and sediment in ULSD

compared to LSD

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About changing fuels:ethanol blended gasoline

Nearly all gas today isblended with ethanol

EPA approved E15 in

cars 2007 and newer About 1% of todays

cars run on E85 (85%ethanol/15% gasoline)

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Fuel AdditivesAre They Necessary?

Gasoline and diesel fuel contain many additives

essential for good fuel quality and necessary for

good fuel stability and performance:

Stability additives -- prolongs fuel life, limits

oxidation/degradation and metal interactionreactions;

Corrosion inhibitors -- protects metal in fuel

systems;

Conductivity improverslessens static

electricity, prevents fires/explosions;

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Fuel AdditivesAre They Necessary?

Lubricity improversprovides needed

lubrication in diesel injection systems;

Biocidespreventive use minimizes bugs

which may lead to corrosion;

Anti-foulant additivescounteract fueldegradation & contaminant interactions that

lead to filter/injector plugging

Additives generally added at terminals May get used up along the way

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Fuel Degradation

Water is fuels

enemy and must

be managed

Stability additivesslow degradation

Biocides kill bugs

Corrosion

inhibitors

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Fuels

IndustryPractice


NewEngines


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ASTM International - AmericanSociety for Testing and Materials

ASTM is the primaryorganization in the

US for developingfuel standards

Other internationalorganizations exist inCanada, Europe (ISO,BSI, etc.)


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Consensus Organizations

Members work together to produce FuelSpecifications such as ASTM D975 for diesel fuel

and ASTM D4814 for gasoline.

Standard Test Methods (STMs) are needed sotesting for properties is done consistently

D7548 STM for Determination of Accelerated

Iron Corrosion in Petroleum Product Majority vote required, and all concerns and

negative votes are thoroughly discussed.

Consensus process can be lengthy!3


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ASTM requirements

ASTM requirements intended to be metat terminals

Some discussion on developing a

standards for fuel that is fit for use New proposals emphasize industry

practice:

A good industry practice is to drain any freewater from a storage tank before the fuel is

transferred further


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Water and Sediment limits

D975 Diesel fuel shall be visually free of undissolved

water, sediment, and suspended matter.

Max 0.05% dissolved water & sediment

4806 Ethanol

Visibly free of suspended or precipitated

contaminants (clear & bright)


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Factors Affecting Water & Sediment

Temperature Water drops out at higher temperatures

Sediment can also form at different temps

Humidity Biofuels absorb water from air


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Factors Affecting Water & Sediment

As fuels age,degradationoccurs and

sediment forms


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Cleanliness Emphasized

One ASTM proposal to updateinformational language on water andsediment states,

Water is virtually everywhere andexists in multiple forms from solid, toliquid, to vapor

it is critically important that fuel be as

free from water (and particulates) aspossible prior to its introduction intothe engines fuel system.


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ASTM D975 Appendix

Available fuel additives can improve thesuitability of marginal fuels for long-termstorage and thermal stability,

Most additives should be added at therefinery or during the early weeks ofstorage to obtain maximum benefits.

Contamination levels in fuel can be

reduced by storage in tanks kept free ofwater,


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Water monitoring

Operations and maintenance proceduresfor water monitoring and removal havebeen a recommended practice for over

thirty years.

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Fuels

Industry

Practice

RegsRevised

Standards

New

Engines


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INDUSTRY RPS Coordinated Research Council

Diesel Fuel Storage & Handling Guide, #667www.crcao.org

Clean Diesel Fuel Alliance Guidance for Underground Storage Tank Management

at ULSD Dispensing Facilities www.clean-diesel.org

Petroleum Equipment Institute RP900: UST Inspection and Maintenance www.pei.org

US EPAhttp://www.epa.gov/oust/pubs/ommanual.htm
http://www.crcao.org./reports/recentstudies2014/CRC%20667/CRC%20667.pdfhttp://clean-diesel.org/pdf/GuidanceforUndergroundStorageTankManagement_FINAL.pdfhttp://clean-diesel.org/pdf/GuidanceforUndergroundStorageTankManagement_FINAL.pdfhttp://clean-diesel.org/pdf/GuidanceforUndergroundStorageTankManagement_FINAL.pdfhttp://clean-diesel.org/pdf/GuidanceforUndergroundStorageTankManagement_FINAL.pdfhttp://clean-diesel.org/pdf/GuidanceforUndergroundStorageTankManagement_FINAL.pdfhttp://pei.org/LinkClick.aspx?link=107&tabid=65&mid=954http://pei.org/LinkClick.aspx?link=107&tabid=65&mid=954http://www.epa.gov/oust/pubs/ommanual.htmhttp://www.epa.gov/oust/pubs/ommanual.htmhttp://pei.org/LinkClick.aspx?link=107&tabid=65&mid=954http://clean-diesel.org/pdf/GuidanceforUndergroundStorageTankManagement_FINAL.pdfhttp://www.crcao.org./reports/recentstudies2014/CRC%20667/CRC%20667.pdf


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Industry standards: biodiesel

NREL, Biodiesel Handling and Use Guide Higher concentrations = reduced stability

Check for compatibility (steel is compatible)

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http://www.nrel.gov/vehiclesandfuels/pdfs/43672.pdfhttp://www.nrel.gov/vehiclesandfuels/pdfs/43672.pdf


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STI R111, Storage Tank Maintenance


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Recordkeeping Changing Fuels

How to Monitor Tanks

How to Remove Water andContaminants

Change of Service

Verify Monitoring Eqpt Operational

Checklist

STI R111, Storage Tank Maintenance


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Todays factors affecting tank

maintenance Common installation and maintenance

procedures contribute to wateraccumulation:

Open vents Low fill areas

Sloped tank installations

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What works Best?


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Microbial contamination

Reddish, scaly, gritty deposits: corrosionand/or silt in tank

Black or brown deposits: watercontamination has degraded the fuel

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Work with yoursupplier to test

fuel/water anddetermine treatment.


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Microbial Contamination

As microorganisms grow and thrive, theyform a slime

Over time, sludge is formed from the

slime Clogs may not be visible, unlike mold

growth

Sludge breaks off and clogs fuel filters andsmall openings throughout entire system

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Microbial warning signs

Chemically-altered fuel

components attack:

Rubber Fiberglass reinforced

plastic

Tank linings & coatings

Metal

Short filter life or flow slowed to 3-5 gpm Erratic tank gauge readings

Frequent replacement of valves, hoses, etc.

Rotten-egg odor from digestion of fuel by

microorganisms

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Contamination

Contaminants likesalts in water may:

Degrade fuel

chemical structure,yielding substancesdetrimental to systemcomponents

Cause fuel additivesto leave fuel andenter water

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Monitoring tanks: all fuels

Inspect tanks at least monthly Check for water as often as possible

If water is present, remove within 30 days

Best monitoring: automatic tank gauging (ATG)system Some floats may not work with alcohol fuels

Simpler, less expensive: appropriate water paste

on gauge stick Water-sensitive filters and watch for slow

fueling

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Monitoring tanks: ethanol

When ethanols water absorption capacityis reached, excess water separates, causingtwo distinct layers of product:

Top layer: lower octane gasoline, possibly out ofspec

Bottom layer: ethanol/water mix, dispose of

Resulting water bottom: Storage system exposed to ethanol

concentrations greater than 10%

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Monitoring & detection methods

Tank bottom sampling Bacon bombs collect

samples from tank bottom

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Fuel filters Use water absorbing filters to detect slowed

fuel dispensing; filters expand when absorbing

water

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Fuel samples from nozzle Visual evaluation by examining fuel caught in

clear glass container

Clear & Bright test

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M & d h d


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Monitoring & detection methods:Biofuels

Use recommended inspection andmaintenance schedules

Daily monitoring of tanks with ATGs and

water level sensors If gauge shows water one day but not the

next, may indicate water has been absorbedinto ethanol-blend or biodiesel fuel

If ATG records are inconsistent, test withwater paste or bottom sample

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H d


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How to remove water andcontaminants from storage tanks

Multipoint water pumping

Fuel filtration/polishing

Non-entry tank cleaning Physical entry tank cleaning

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Leak Detection & Monitoring

NWGLDE, National Work Group onLeak Detection Evaluation

Independent group consisting of 11 state and

federal EPA employees New protocols for leak detection

In future, leak detection equipment will

have to be rated for ethanol use

P i k f h i f l


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Preparing tanks for changes in fueltype

Tank and related dispensing equipmentmust be thoroughly cleaned

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STI R111 hl i i


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STI R111s monthly inspection

checklist Inspect tanks monthly

Checklist on pages 12-

13 of R111 document

Covers all inspectionrecommendations

Your record of tankinspection andmaintenance

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I ti d M i t f


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Inspection and Maintenance ofTank Systems

STI WebinarFebruary, 2015

www.steeltank.com


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Tank TalkSTI Publication

August 2014, Todays New Engines, R Gault


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Lorri Grainawi

STI/SPFA

944 Donata Court

Lake Zurich, IL 60047

Web: www.steeltank.com

Phone: 847/550-3831

E-Mail: [email protected]

Thank you!

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