Above Ground Storage Tank Oil Spills: Applications and Case Studies

Front Cover
Above Ground Storage Tank Oil Spills
Copyright Page
Contents
List of contributors
Preface
Oils spilled on land
Oils spilled on water
Reference
Acknowledgment
Introduction
1 Preventative design and issues
1. Assessment of oil storage tanks performance containing cracks and cavities
1.1 Introduction
1.2 Various types of oil storage tanks and their components
1.2.1 Main components of an oil storage reservoir
1.3 Common defects in the oil storage tank and their causes
1.3.1 Corrosion
1.3.1.1 Classification of corrosion
1.3.1.2 Pitting corrosion
1.3.1.3 Corrosion in oil storage tanks
1.3.2 Cracking
1.4 Design, construction, technical inspection, and repair standards
1.5 Methods of dealing with defect damage to prevent decommissioning of storage tanks
1.5.1 Diagnosis of defects
1.5.2 Non-destructive methods of identifying locations and corrosion rates in tanks
1.5.2.1 Eddy current test
1.5.2.2 Acoustic emissions method
1.5.2.3 Digital radiography
1.5.3 Methods for dealing with crack defects in oil storage tanks
1.5.4 Creating a suitable cover for the inner surface of the tanks
1.5.5 Cathodic protection inside tanks
1.6 Analysis of tank behavior with defects
1.6.1 Finite element simulations
1.6.1.1 Finite element model of crack and pitting corrosion
1.6.2 Taguchi approach
1.6.3 Multiple regression techniques
1.6.4 Response surface method
1.7 Conclusions
References
2. Wind effect on atmospheric tanks
2.1 Introduction
2.2 History of natural events affecting industrial equipment
2.2.1 Natural hazards
2.2.2 Exposure and vulnerability
2.2.3 Risk
2.3 Storage tanks and strong winds
2.3.1 Strong winds as hazards
2.3.2 Atmospheric above-ground tanks characterization
2.3.2.1 Storage tank shell
2.3.2.2 Storage tank roof
2.3.2.3 Storage tank base
2.3.3 Definition of possible accidental scenarios
2.3.4 Structural and natural hazard analysis
2.3.4.1 Storage tanks damaged by strong winds
2.3.4.1.1 Shell buckling
2.3.4.1.2 Overturning
2.3.4.1.3 Debris impact
2.3.4.2 Definition of limit state equations
2.3.5 Storage tanks fragility analysis
2.3.5.1 Fragility curves
2.3.5.2 Failure probability
2.3.5.3 Probit functions to estimate damage probability
2.3.6 Storage tanks vulnerability analysis
2.3.6.1 Frequency of final accidental scenario
2.4 Conclusions
References
3. Seismic performance of liquid storage tanks
3.1 Introduction
3.2 Seismic response
3.2.1 Hydrodynamic effects
3.2.2 Response of unanchored tanks
3.2.3 Response of anchored tanks
3.3 Typical failure modes
3.4 Shell buckling
3.4.1 Analytical solutions
3.4.2 Dynamic buckling assessment
3.5 Factors affecting the seismic performance
3.5.1 Geometrical specifications
3.5.2 The relative amount of content
3.5.3 Strong ground motion characteristics
3.5.4 Fabrication quality and imperfection
3.5.5 Corrosion and maintenance
3.6 Seismic design codes
3.6.1 Seismic performance target
3.6.2 Mechanical analogy
3.6.3 Vertical seismic effects
3.6.4 Anchorage criteria
3.6.5 Freeboard requirement
3.7 Fragility based seismic performance assessment
3.8 New horizons for further developments
3.9 Conclusions
References
4. Hurricane performance and assessment models
4.1 Introduction
4.2 Hurricane failure modes
4.2.1 Wind-induced failures
4.2.2 Storm surge failures
4.2.3 Wave-induced failures
4.2.4 Extreme precipitation induced failures
4.3 Hurricane performance assessment models
4.3.1 Wind load
4.3.1.1 Buckling
4.3.1.2 Floating roof failure
4.3.1.3 Other failures
4.3.2 Storm surge loads
4.3.2.1 Dislocation failures (flotation and sliding)
4.3.2.2 Buckling failure
4.3.2.3 Other failure modes
4.3.2.4 System failure
4.3.3 Wave loads
4.3.4 Rainfall loads
4.4 Discussion
4.5 Summary
References
5. Tank design
5.1 Torque-free theory of rotating thin shells
5.1.1 Geometrical characteristics of general rotating thin shells
5.1.2 Geometric characteristics of several common shells
5.1.2.1 Cylindrical shell
5.1.2.2 Spherical shell
5.1.2.3 Ellipsoid shell
5.1.3 General equations of the torque-free theory
5.1.4 Application conditions for torque-free theory
5.1.4.1 Geometric continuity
5.1.4.2 Continuous external load
5.1.4.3 Continuous constraint
5.1.5 Application of torque-free theory
5.1.5.1 Effect of gas pressure
5.1.5.2 Effect of liquid pressure
5.2 The edge problem
5.2.1 Reason for the formation of discontinuous stress
5.2.2 Calculation method for discontinuous stress
5.2.3 Characteristics and treatments of discontinuous stress
5.2.3.1 Characteristics of discontinuous stress
5.2.3.2 Treatment of discontinuous stress in engineering problems
5.3 Design of inner pressure cylinder
5.3.1 Strength calculation of internal pressure cylinder
5.3.1.1 Tank design
5.3.1.2 Tank check
5.3.2 Determination of design technical parameters
5.3.2.1 The inner diameter of the container Di
5.3.2.2 Working pressure pw and design pressure p
5.3.2.3 Calculated pressure pc
5.3.2.4 Design temperature
5.3.2.5 Allowable stress
5.3.2.6 Weld joint coefficient φ
5.3.2.7 Thickness and additional thickness
5.4 Design of internal pressure spherical shell
5.5 Design of internal pressure dished head
5.5.1 Internal pressure convex dished head
5.5.1.1 Hemispherical head
5.5.1.2 Ellipsoid head
5.5.1.3 Dished head
5.5.1.4 Spherical crown head
5.5.2 Internal pressure cone head thickness calculation
5.5.2.1 Conical shell without folding under internal pressure
5.5.2.2 Flanged conical shell under internal pressure
5.5.2.3 Flathead
5.5.2.4 Selection of head
5.6 Pressure test
5.6.1 Pressure bearing test
5.6.1.1 Test medium
5.6.1.2 Test pressure
5.6.1.3 Stress check
5.6.1.4 Test temperature
5.6.1.5 Test method
5.6.1.6 Acceptable quality level
5.6.2 Airtightness test
5.7 Summary
References
6. On buckling of oil storage tanks under nearby explosions and fire
6.1 Introduction
6.2 A review of selected accidents involving explosions and fire in tank farms
6.2.1 Case study: The Bayamon Accident in Puerto Rico, 2009
6.2.2 Brief description of other accidents
6.2.3 Common features of accidents and lessons learned
6.3 Effects due to explosions
6.3.1 Basic features of explosions affecting nearby tanks
6.3.2 Evidence from small-scale testing of pressures reaching a tank
6.4 Modeling pressures due to explosions reaching a target tank
6.4.1 Simplified models of pressure distribution around tanks due to a nearby explosion
6.4.2 Advanced models of the source of an explosion and its consequences on tanks
6.5 Structural behavior of tanks under impulsive loads
6.5.1 Computational modeling
6.5.2 Dynamic buckling criteria
6.5.3 Structural behavior of open-topped tanks with a wind girder under an explosion
6.5.4 Effects of explosions in very large tanks
6.5.5 Domino effects under blast loads
6.6 Effects due to fire
6.6.1 Introduction to fire effects in tanks
6.6.2 Summary of results from small-scale tests
6.7 Modeling fire effects reaching a target tank
6.7.1 Simplified models of temperature distribution around tanks due to a nearby fire
6.7.2 Advanced modeling of temperature distribution around tanks due to a nearby fire
6.7.3 Main differences between simplified and advanced models
6.8 Structural response and buckling under thermal loads
6.8.1 Types of analysis
6.8.2 Thermal buckling of tanks
6.8.3 Postbuckling behavior
6.8.4 Other tank features that modify the structural response
6.8.5 Effect of multiple sources of fire
6.8.6 Domino effects under fire
6.9 Areas for further research
6.9.1 Tests on small-scale tanks under thermal loads
6.9.2 Tests on small-scale tanks under blast loads
6.9.3 Modeling tanks under fire
6.9.4 Modeling tanks under blast loads
6.9.5 Design recommendations
6.9.6 Fragility and risk assessment
Acknowledgments
Nomenclature
Acronyms
References
Appendix 6.1: Summary of critical temperatures for tanks with a conical roof
2 Case histories
7. The Ashland oil spill
7.1 Incident summary
7.2 Background
7.3 Initial incident and response actions
7.4 Findings and lessons learned concerning the response
7.5 Drinking-water response actions
7.6 Findings and lessons learned water supplies
7.6.1 Contaminated marine debris
7.7 Crisis management response actions
7.8 Crisis management findings and lessons learned
7.9 The tank that failed
7.10 Causes of tank failure findings and lessons learned
7.11 Followup activities and the aftermath of the Ashland oil spill incident
References
Further reading
3 Legislation
8. An overview of typical legislation governing the design, construction, and operation of storage tanks
8.1 Introduction
8.2 Basics of regulation
8.3 Siting
8.4 Separations
8.5 Identification of storage facilities
8.6 Construction
8.7 Dike construction
8.7.1 Liners
8.7.1.1 Compacted clay liners
8.7.1.2 Natural liners
8.7.1.3 Synthetic liners
8.7.1.3.1 Coated fabrics and laminates
8.7.1.3.2 Extruded film or sheet
8.7.1.3.3 Spray-on coatings
8.8 Discharge of water from dyked area
8.9 Double-walled tanks
8.10 Piping systems
8.10.1 Standards applicable
8.10.2 Above-ground piping
8.10.3 Below-ground piping
8.11 Leak detection
8.12 Corrosion protection
8.13 Inspection
8.14 Record keeping
8.15 Leak testing or integrity testing
8.16 Withdrawal of storage tanks from service
8.16.1 Temporary withdrawal from service (usually time specified—e.g., <180 days)
8.16.2 Temporary withdrawal from service exceeding a certain time (e.g., >180 days)
8.16.3 Permanent withdrawal from service
8.16.4 Replacement of an existing aboveground storage tank or addition of a new tank to an existing tank farm
References
Appendix A Glossary of storage terms (ERCB, 2001)
Appendix B Standards applicable to above-ground storage tanks
4 Risk analysis
9. Canadian storage tank spill risk analysis
9.1 Introduction
9.2 Total spills in Canada
9.3 Comparison of Canadian to US data
9.4 Analysis of storage tank spills in Canada
9.5 Summary and conclusions
References
Index
Back Cover