Wayne Geyer
Steel Tank Institute
November 18, 2013

 Association of 180 fabricating and affiliate companies of steel construction products – shop-fab tanks, field erect tanks, pipe, pressure vessels and other special fabricated products
 STI members account for nearly all of the total shop fabricated underground steel storage tank production capacity in North America

2012 Annual Product Awards:
Steel Fabricated Products www.steeltank.com

What does the Steel Tank Institute do?
 UST and AST tank technologies
 Industry standards and recommended practices
 License manufacturers to build tanks to STI specifications
 Quality control
 Information resource
 Certification
4 – 50,000 Gallon Permatanks
Installed at Northwestern
Univeristy

 Every tank built with an STI labeled is inspected by tank fabricator to meet STI specification
 Tank is “registered” with STI
 STI maintains database with over 400,000 entries

 All STI labeled UST’s subject to 3 rd party warranty
 STICO Mutual has strong claims management program
 STI gets feedback on quality and performance

• 927 Certified SP001 Aboveground
Storage Tank Inspectors
• 484 Certified Cathodic Protection
Testers
• Over 130,000 sti-P3 tanks tested for cathodic protection through
WatchDog program
• NEW: On Line Learning Program
• T*I*M Tank Integrity Management

STI Shop-Fabricated Tank Programs
• > 100 tank shops licensed and inspected
• 14 tank fabrication standards
• 19 recommended practices for testing, installation and inspection
–
NEW: R111 Storage Tank
Maintenance
–
Under Development: SP131 - UST
Inspection, Repair, & Modification

35 000
T a n
30 000 k
25 000
1988
t s i
U n
20 000
15 000
B l t i u
10 000
5 000
0
1971
1998
2008
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41
Years in Number after 1970

 Primarily used at service stations today
 Tanks are getting larger


STI Database
Average capacity in 2013 for jacketed tank exceeds 15,000 gallons
 25 years ago, the typical
UST at a service station was 8000 – 10,000 gallons

 Compartment tanks have become very common for both UST’s and AST’s
 Multiple fuel types can be stored within one tank unit
 Provides user/owner versatility as more fuels develop

 UL 58 is the principle standard for steel tank construction – single wall and double wall steel
 UL 1746 is the principle standard for corrosion control and for jacketed
(non-metallic outer wall) tank construction

 Regulations require all tanks incorporate secondary containment
 Today, jacketed tanks are favored by many buyers as outer containment provides a corrosion barrier and secondary containment
 Other corrosion systems use two walls of steel

Fabricating Steel Secondary
Containment
 After the primary tank is built and tested, the outer wall is fabricated atop the primary tank.
 The second wall is intimately wrapped atop the primary tank wall.

 Most fabricators will test the interstice by bleeding air from a 3-5 psi pressurized inner tank into the secondary tank.
The volume of the interstice is very small and can get pressurized rapidly.
 Access to the interstice can be fabricated in different ways

Production Test to Verify Both
Walls are Tight
 Upon completion of production testing of the interstice with positive air pressure, and soap testing the welds of the secondary containment, all air is released.
 Then a vacuum is pulled within the interstice and monitored by the fabricator for tightness over time.

 After ancillary equipment installed, coatings applied, etc. the tank is made ready for shipment.
 Fabricators apply a vacuum into the interstice of secondary containment tanks.

 After the vacuum is applied, the tank is held in storage until it is made ready for delivery
 The vacuum remains on the tank during storage, delivery, and during much of the installation.
 An easy view of the vacuum gauge to verify retention of the vacuum assures that both walls remain tight.

 E10, E15, E85, B2, B20, B100
 Steel Tank Manufacturer
Certification Statements
 STI Web Site
 Performance
 Tanks are Cleaner – Sludge
 Biodiesel Shelf Life
 Water Concerns
 Phase Separation - Ethanol

Recent Events
Biofuels
• Sumps
• EPA ORD Research
• NIST Research
• Publications
• “Compatibility of UST
Systems with Biofuels,”
• Published by ASTSWMO
• Case Studies
• Research and Work
Groups
• Underground tanks storing E85
23

Ultra Low Sulfur Diesel Issues
• Corrosion of metal components within
FRP tanks storing ULSD
• Clean Diesel Fuel Alliance supported research from Battelle Labs completed in 2012
• Further studies under consideration
• STI Research
• Tanknology hired to visually examine the insides of steel and FRP ULSD tanks
• Fuel samples extracted and tested
• Example – Las Vegas service station tanks under same owner
• FRP tank vapor control fitting – top right photo
• Steel tank vapor control fitting – bottom right photo
24

Inspection and Maintenance of the Tank System

Inspection and
Maintenance
STI R111
Storage Tank Maintenance
STI SP001 AST Inspection

Aboveground Storage Tanks
• Cylindrical
• Rectangular
• Vertical
• Horizontal
• Double Wall
• Diked
• Fire-protected
• Gen-Base
• FieldErected

 Most popular choice for shop-fabricated tanks for:
 Fleet motor vehicle fueling applications
 Fuel for emergency power generators
 Bulk oil and chemical storage
 Secondary containment

 UL 142 is the principle standard for steel tank construction – single wall and double wall steel.
 UL 2085 is the principle standard for two hour fire protected tank construction.

 Secondary contained shop-fabricated steel tanks are preferred:
 Serves as spill control to meet fire codes
 Meets SPCC rules with proper use of overfill prevention equipment
 Double wall construction preferred over diking

AST’s with 2-Hr Fire Test Ratings
31

 Protected aboveground tanks preferred when:
 Installed in close proximity to buildings & property lines
 Dispenser mounted on tank
 Minimize fire safety hazards
 Meet codes for motor vehicle fuel dispensing

 EPA references STI
SP001 standard for smaller tank inspection and integrity verification
 Category 1 preferred
 Double wall tanks can be easily tested with vacuum to prove containment integrity
Category 3 – Higher Risk to Environment

Facilities with a mix of tanks require one type of inspector

Release Prevention
Barrier (RPB)
 Liquid containment barrier
 Under the AST
 Diverts leaks toward the perimeter of the
AST where they can be easily detected

More Risk
Tank Size
Shop built tanks
0 - 1100
1101 -
5,000
5,001 -
30,000
30,001 -
50,000
Field erected
Portable containers
Category 1
P
P
P, E(20)
P, E(20)
P, E(5), I(10)
P
Category 2
P
P, E&L(10)
[P, E(10)& I(20)] or
[P, E(5) & L(10)]
P, E&L(5), I(15)
P, E(5), I(10)
P
Category 3
P, E&L(10)
[P, E&L(5), I(10)] or
[P, E(5) & L(2)]
[P, E&L(5), I(10)] or
[P, E(5) & L(1)]
P, E&L(5), I(10)
P, E(5), I(10)
P **

Category 1 – Secondary
Containment and CRDM
Double-wall Tank with Overfill Prevention
Tank in a
Concrete Dike

Wayne Geyer
WGeyer @ steeltank.com
847-438-8265 www.steeltank.com