STORAGE TANK MAINTENANCE AND COST SAVINGS PROGRAM By Alan Watson

Let’s go back to basic’s American Petroleum Institute Engineering Equipment Materials Users’ Association Environmentally friendly Let’s go back to basic’s

NOTE: EEMUA is a publication and can go into more depth and detail. API & EEMUA American Petroleum Institute (API) have developed Standards API 650 “Welded Steel Tanks for Oil Storage API 653 “Tank Inspection, Repair, Alteration and Reconstruction” Publication. Engineering Equipment Material Users Association (EEMUA) EEMUA 159 “User’s Guide to the Maintenance and Inspection of Above-Ground Vertical Cylindrical Steel Storage Tanks “ EEMUA 183 “Guide for the prevention of Leakage from Vertical, Cylindrical Steel Storage tanks” NOTE: EEMUA is a publication and can go into more depth and detail. Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 © 3

A. R. WATSON INC All rights reserved 2008 © Alan Watson After lifting over 1000 tanks around the world and seeing the tank foundations that have fail and ones that have work. I am on the API tank fabrication committee and I am rewriting API 650 Appendix “B” “Recommended Foundation Design” I am working with EEMUA Storage Tank Committee and I have engaged Tyler Ley, Ph.D., P.E. of Oklahoma State University to write a paper on tank foundations This presentation is based on my experience and views. Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 © 4

AST Operating Locations are all over the world Join API 653 & EEMUA 159 together to have One world wide inspection Standard If you THINK that it is SAFE don’t do it ~ Do it when you KNOW that it is SAFE A. R. WATSON INC All rights reserved 2008 © 5

Does any of this look familiar?

Tomorrow is your reward for working SAFE today EEMUA 159 Corrosion of Tanks The major causes of underside corrosion are: Poor drainage around tank Water migrating under the tank Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 © 7

A. R. WATSON INC All rights reserved 2008 © EEMUA 159 Corrosion of Tanks Tank on Railway Ties Poor Foundation Material Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 © 8

A. R. WATSON INC All rights reserved 2008 © EEMUA 159 Corrosion of Tanks On concrete ring wall On stone Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 © 9

A. R. WATSON INC All rights reserved 2008 © EEMUA 159 Corrosion of Tanks Construction of Concrete ring wall Tank sitting on ConcreteTank Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 © 10

A. R. WATSON INC All rights reserved 2008 © EEMUA 159 Corrosion of Tanks On concrete ring wall Insulation holding moisture Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 © 11

A. R. WATSON INC All rights reserved 2008 © EEMUA 159 Corrosion of Tanks Moisture held under tank by steel bar No holes in concrete ring wall If you THINK that it is SAFE don’t do it ~ Do it when you KNOW that it is SAFE A. R. WATSON INC All rights reserved 2008 ©

Ground Bearing Pressure Tomorrow is your reward for working SAFE today Water laying around ring wall foundation Ground outside foundation cracked and allowing water to go under ring wall Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 © 13

Tomorrow is your reward for working SAFE today Ground Bearing Pressure Tank shell Ground level Tank Bottom Concrete ring wall Water changes ground bearing pressure under concrete ring wall Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

Tomorrow is your reward for working SAFE today EEMUA 159 Problems Caused by Soil Settlement Even soil settlements are generally not dangerous because they occur gradually and increase uniformly. When they become excessive however, some remedial action may be necessary. The extent of settlement should therefore be checked, to avoid problems during operation of the tank. Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 © 15

A. R. WATSON INC All rights reserved 2008 © EEMUA 159 Edge settlement Edge settlement may occur when the shell penetrates into the foundation Edge settlement may be caused when the tank pad shoulder is damaged or eroded by rain and wind. Edge settlement may be caused by a tank pad shoulder with insufficient width or poor quality construction. If you THINK that it is SAFE don’t do it ~ Do it when you KNOW that it is SAFE A. R. WATSON INC All rights reserved 2008 ©

A. R. WATSON INC All rights reserved 2008 © EEMUA 159 Edge settlement Tank shell settled below ground Edge settlement If you THINK that it is SAFE don’t do it ~ Do it when you KNOW that it is SAFE A. R. WATSON INC All rights reserved 2008 ©

A. R. WATSON INC All rights reserved 2008 © Lost Capacity in Tank Lost storage capacity over whole tank Product level Easily fixed Shell edge punching causes lost product capacity in tank Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

A. R. WATSON INC All rights reserved 2008 © EEMUA 159 Corrosion of Tanks Cathode protection may have been installed after the tank has been commissioned. In this case it makes it difficult to ensure that sufficient protective current reaches all areas of the bottom. Significant tank settlement that lowers the tank below a good drainage level. This may lead to corrosion of the annular plate around the tank perimeter. High natural water or underground springs If you THINK that it is SAFE don’t do it ~ Do it when you KNOW that it is SAFE A. R. WATSON INC All rights reserved 2008 ©

A. R. WATSON INC All rights reserved 2008 © Cathodic Protection (C.P.) & Painting If a tank has a good foundation C.P. is not required, C.P. is costly to install and maintain and in some cases it can cause accelerated corrosion Painting the underside of a tank bottom will not add any additional protection to the tank bottom If you THINK that it is SAFE don’t do it ~ Do it when you KNOW that it is SAFE A. R. WATSON INC All rights reserved 2008 © 20

A. R. WATSON INC All rights reserved 2008 © Uneven foundation settlement - 3 in -1in - 4 in Causes the top of the tank to become oval and jam the floating roof. Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

A. R. WATSON INC All rights reserved 2008 © Tank Foundation Settlement Tank Foundation Ground level Compacted Ground A. R. WATSON INC All rights reserved 2008 ©

A. R. WATSON INC All rights reserved 2008 © EEMUA 183 Double Steel Bottoms Installation of a new steel bottom above the old steel bottom with moisture between the bottoms causes the new steel bottom to become the sacrificial anode and this condition will cause the new bottom to corrode at a faster rate than a single bottom. If you THINK that it is SAFE don’t do it ~ Do it when you KNOW that it is SAFE A. R. WATSON INC All rights reserved 2008 © 23

A. R. WATSON INC All rights reserved 2008 © EEMUA 183 Double Steel Bottoms - The installation of double bottoms should be carefully evaluated, taking into account the relatively high cost of the design and of the rectification work required when tanks undergo progressive settlement. - Also the lower or secondary bottom cannot be inspected even when the tank is out of service and consequently its integrity is always questionable. If you THINK that it is SAFE don’t do it ~ Do it when you KNOW that it is SAFE A. R. WATSON INC All rights reserved 2008 ©

A. R. WATSON INC All rights reserved 2008 © EEMUA 183 Double Steel Bottoms Complicated to Install Relocation of Nozzles & Manholes Sensitive to tank Settlements Re-levelling is virtually impossible Removal of contaminated material from double bottom (following leakage) potentially hazardous If you THINK that it is SAFE don’t do it ~ Do it when you KNOW that it is SAFE A. R. WATSON INC All rights reserved 2008 ©

Tomorrow is your reward for working SAFE today Inspection NDT inspection has limitations and flaws and cannot inspect 100% of the tank floor. It cannot inspect the critical zone around the shell to annular weld, lap joints, under the roof columns, around tank sumps. Sometimes packed rust and water in the foundations shows up as good metal. Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 © 26

A. R. WATSON INC All rights reserved 2008 © Piled Foundations Concrete Slab with Piles Piled foundations are very expensive. The tank can be built on the ground, water loaded and then lifted and any settlement remediated is cheaper than installing piled foundations. Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 © 27

Concrete verses Crushed Rock Ring Walls Concrete Ring Wall Crushed Rock Ring Wall Concrete Crushed Rock Concrete ring wall are expensive to install and have little advantage over a crushed rock ring wall. If a tank has been in service for a number of years the ground under the tank is now compacted from the loading of the tank. Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 © 28

A. R. WATSON INC All rights reserved 2008 © Tank Foundations It has been identified that many of the problems with above ground storage tanks start at the foundations. Tank’s not properly founded are bound to fail. When a tank is built on a good foundations then the tank will last indefinitely without any problems Tank Foundations are built with the following: Risk Cost Constructability Schedule If you THINK that it is SAFE don’t do it ~ Do it when you KNOW that it is SAFE A. R. WATSON INC All rights reserved 2008 © 29

Tomorrow is your reward for working SAFE today EEMUA 183 Conclusions Codes and standards covering the design and construction of storage tanks are based on over 100 years of experience. There is no need to question the integrity of the tank structure as a primary container, provided it is properly designed and built to recognized standards. Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

Tomorrow is your reward for working SAFE today EEMUA 183 Conclusions Effective prevention of ground and ground water pollution from storage tanks depends on the design and construction of a good foundation, a properly construction tank bottom and regular, effective inspection. Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

Tomorrow is your reward for working SAFE today EEMUA 183 Summary API Standards 650 and 653 were produced as a guide for the owners / operators State regulators are now starting to mandate the API Standards into State regulations API Standards have never investigated to see if some of the recommendations work Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

Tomorrow is your reward for working SAFE today Summary Why install cathodic protection API 651 Why install double bottoms API 650 Appendix “I” Why install concrete under tanks API 650 Appendix “B” What is the best type of tank foundation to install We are still making the same tank foundation mistakes. Tanks built on good foundations have lasted 50 years and more years. Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

Foundation design is BS 2654 as shown in EEMUA 183 Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 © 34

Oklahoma State University THE NEXT STEP Oklahoma State University “Determining the Long Term Performance of Tank Foundations through the use of Case Studies” A. R. WATSON INC All rights reserved 2008 ©

Oklahoma State University Tank Foundation Study With assistance from; American Petroleum Institute (API) US Defense (DOD) Engineering Equipment and Materials Association (EEMUA) International Liquid Terminals Association (ILTA) Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

Oklahoma State University Tank Foundation Study Study TEAM Tyler Ley, P.E., Ph.D William F. McTerman, P.E., Ph.D Steve Cross P.E., Ph.D Civil and Environmental Engineering Oklahoma State University, Stillwater, OK Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

Oklahoma State University Tank Foundation Study AST after 20 years of service more than 20% require foundation repairs. Current owners suggest this number is higher. Primary function of a tank foundation is to minimize differential settlement and prevent corrosion Tank owners would benefit from an unbiased review based on inspection records and case studies The use of case studies to evaluate the performance of infrastructure system has been successfully used before (FHWA) Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

Oklahoma State University Tank Foundation Study The OSU research team has already been in contact with several international owners that have agreed to and have supplied construction and inspection records for over 1000 tanks in North America The records obtained to date have shown over 15 varieties of tank foundations While some of these foundations have performed satisfactory others have not and have required significant investment. People have theories over which foundations are the best. No one has taken an unbiased look at the actual performance of different foundations in different environments Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

Oklahoma State University Tank Foundation Study OSU will require additional feedback from tank owners / operators / Consultants / inspectors from around the world to increase the size of the data base. Repairs performed on the tank are also of interest to the research team in conjunction with the type of foundation used, this information can be crucial in understanding the corrosion / settlement of the tank. Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

Oklahoma State University Tank Foundation Study The assembled database will be used to; to investigate the performance of design and construction of new tank foundations effectiveness of cathodic protection performance of double bottom tank repairs tank foundation repair recommendation and strategies Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

Oklahoma State University Tank Foundation Study Cost savings No cathodic protection, expensive to install and maintain No concrete under tank, expensive to install No double bottoms, difficult to install under external floating roof (EEMUA do not recommend double bottoms) Existing tank foundation repairs, tank lifting EEMUA 159 Barrels Build New Tank Lift the Tank Level the Tank Install Rock Foundation 20,000 $400,000 $80,000 $40,000 $50,000 35,000 $700,000 $100,000 $90,000 55,000 $1,100,000 $120,000 $70,000 Tomorrow is your reward for working SAFE today A. R. WATSON INC All rights reserved 2008 ©

THANK YOU FOR YOUR TIME QUESTIONS?