Above Ground Storage TankDesign, Inspection, and Compliance Management By Gregory Coppola, P.E. Kinder Morgan Energy Partners, L.P. Introduction • Kinder Morgan Overview – Midstream Energy Company – 900+ Storage Tanks in Pacific Region – Critical Infrastructure for Fuel Distribution Completed New Tanks El Paso, TX Organization of the Presentation • • • • • Objective of the Presentation API Recommended Practice Tank Construction and Tank Components Out-of-Service Inspections Regulatory Framework – SPCC Rule – APSA – DOT Regulations – Air Regulations – Federal and Local Objective of the Presentation • Provide CUPA members with an overview of petroleum storage tanks. • Provide an introduction to applicable regulations. • Assist with CUPA regulation under Assembly Bill 1130, The Aboveground Petroleum Storage Act. Aboveground Petroleum Storage Act (APSA), Assembly Bill 1130 Effective January 1, 2008 • Transfers the responsibility for the implementation, enforcement and administration of the Aboveground Petroleum ACT (APSA) from the State Water Resources Control Board (SWRCB) to the CUPA’s. • California Health and Safety Code Chapter 6.67, Sections 25270 – 25270.13 are also known as the APSA. • APSA will be discussed in more detail later in the presentation. API Recommended Practices API Recommended Practices API 650 • API 650 – Design Standard for welded steel tanks for oil and fuel storage. • Typically used for large field fabricated storage tanks operating at low pressures or atmospheric pressures. • The standard covers materials of construction, design, fabrication/erection, construction inspection, and welding procedures. API 650 Welded Tanks for Oil Storage • • • • • • • Scope Reference Definitions Materials Design Fabrication Erection • Methods of Inspection • Welding Procedures • Marking Tank Schematics • The following schematics show the various appurtenances for: – Cone Roof Tanks – Internal Floating Roof (IFR) Tank with Top Foam Injection and Vapor Recovery – Cable Suspended IFR – External Floating Roof (EFR) – EFR with Dome Cone Roof Tank IFR Tank w/Top Foam and Vapor Recovery Cable Suspended Internal Floating Roof External Floating Roof Tank EFR Tank with Aluminum Dome Tank Foundations • Foundation Types – Earth Foundations – Gravel/Asphalt Surface – Ring Walls – Slab – Piles with Ring or Slab Caps Tank Foundations (Con’t) • Design Concepts – Vertical Loading • Liquid pressures • Shell and roof loads – Overturning • Wind • Seismic – Foundation Settlement Liner Installation Foundation Rebar Concrete Tank Foundation Tank Bottoms • Constructed of overlapping steel plates. • Plates joined by manual or automatic arc welding techniques. • Tank bottom to shell welds undergo the most stress and are considered critical welds. Tank Bottom – In Progress View of Tank Bottom Beneath IFR Includes Center Column, Roof Legs, and Reinforcing Pads Tank Double Bottoms • Typical components (starting from below) – Lower tank bottom – HDPE liner – Sand or concrete with drainage system – Upper tank bottom Shell Design • Tank shells are constructed from courses of steel plates. • The designer will calculate a steel thickness for each course. • The bottom courses are thicker steel due to hydrostatic pressure. • Shell design criteria include hydrostatics and wind buckling. • Thickness includes corrosion allowance. Construction of First Course – Crane Inside Construction of First Course Hanging Plate for 4th Shell Course Nozzles and Penetrations • Openings in the shell result in higher stress. • Repads or thickened inserts may be required. • Stress relieving may be required. Manway with Davit Arm Fixed Roof Types • Self-supported – Cones – Domes and Umbrellas with stiffeners • Supported Cone Roofs – Columns are inside tank • Aluminum Geodesic Domes Roof Construction – Bull Wheel and Center Column Roof Rafter Construction Lifting Cone Roof Center Column Support Supported Roof, Partially Completed Aluminum Dome, Lifting on to EFR Tank Frangible Roof Joints • Roof to shell junction designed to fail first in an emergency. • Future piping and maintenance must not interfere with the functioning of the frangible roof joint. Fixed Roof – 24” Mushroom Circulation Vent, Sample Vent and Skid-Proof Surface Coating Floating Roofs, Objectives • • • • Reduces air emissions Prevents product loss Meets regulatory requirements Improves fire safety Floating Roofs • Material of Construction: Steel or Aluminum • Roof Types – Floating pan – Bulkhead – Internal pontoon – Double deck – Honeycomb or Foam Core – Cable suspended Aluminum IFR Pontoon Construction Floating Roof Support Leg and Sleeve (High Leg Position) Reinforcing Pad for Roof Leg Floating Roof Seals • Primary Seals – Liquid mounted foam logs – Liquid mounted shoe seals – Vapor mounted foam logs – Vapor Mounted wipers • Secondary Seals – Elastomeric wipers – Metallic wipers Mechanical Primary Shoe Seal in IFR Compression Plate Secondary Seal with Wiper Tip on EFR Tank Other Tank Appurtenances • • • • • • • • Spiral stairway Ladders Level gauges Pressure vacuum vents Shell and roof manways Inlet diffusers Drain sumps Roof drain hoses Spiral Stairway Leading up the Tank Exterior Internal Ladders with 8-inch Slotted Gauge Pole Level Gauging Systems • Mechanical level gauging systems are frequently used. There are multiple alarm levels. • Radar gauges can be mounted at the fixed roof or in a gauge well. • The gauging system often ties into the overall facility SCADA system. • A redundant alarm is recommended by API. Level Gauging System Mounted on Tank Exterior Sample Hatch Top View of IFR Two 12” Pressure Vacuum Vents and Center Column Drip Tray for Center Column with Hold Down Chains Ladder Well Drip Tray and Chained Slide Plate Tank Bottom Sump Newly Painted Ladder, Slotted Gauge Pole, and Sump Slotted Inlet Diffuser Slotted pipe Inlet Diffuser -- Hole Type Suction Line Trough Water Draw Piping Coiled Roof Drain Hose Beneath Internal Floating Roof Reinstalling a Door Sheet at the Conclusion of the Project Fire Systems • Refer to NFPA 11 – Standard for Low-, Medium-, and High-Expansion Foam. • The Standard contains design criteria for hydrocarbon storage tanks. • The criteria include: – Application rate – Discharge time – Minimum number of outlets Fire Systems (Con’t) • Fixed roof tanks may be designed with subsurface injections. • Floating roof tanks will be designed with over-the-top injection. • Foam dams are used to focus on fighting seal area fires. • Other fire systems are designed for “Full Surface Fires.” Foam Fire Systems Foam Chamber Installed in Tank Shell Tank Cathodic Protection • Galvanic Corrosion – Can occur on the underside of a tank bottom causing oxidation, general corrosion, and pitting. – Galvanic cell requires: • Anode – active metal at the tank bottom. • Cathode – less active metal in the vicinity of the tank. • Electrical path – tank bottom and soil. • Electrolyte. Tank Cathodic Protection (Con’t) • Impressed Current Systems – Includes a DC current source created by a rectifier and a buried impressed current anode. – Creates a current to counteract the galvanic cell and forces current to the tank bottom to prevent oxidation (loss of electrons). • Sacrificial Anode – The anode losses electrons rather than the tank. Impressed Current Corrosion Protection API Recommended Practices API 653 • API 653 – Tank Inspection, Repair, Alteration and Reconstruction. • Tanks are inspected to determine their suitability for service. • The standard includes recommendations for tank inspection interval. • This standard governs out of service inspection and repair work. API 653 Tank Inspection, Repair, Alteration and Reconstruction • • • • • • • • Scope Reference Definitions Suitability for Service Brittle Fracture Inspection Materials Design Considerations • Tank Repair and Alterations • Dismantling/Reconstr uction • Welding • Examination Testing • Marking Other API Methods Relevant to Tanks • API 651 – Cathodic Protection for Storage Tanks. • API 652 – Linings for Storage Tanks. Standard for Internal Coating. • API 2000 – Venting for Atmospheric and Low Pressure Tanks. • API 2350 – Overfill Protection for Storage Tanks. API Recommended Inspection Schedule • Routine In-Service Visual Inspection – Frequency not to exceed one month. – Can be performed by Owner/Operator personnel. • External In-Service Inspection – Visual inspection of the tank exterior . – By Authorized Inspector (API 653 Certified). – Frequency not to exceed 5 years, but may be more frequent based on corrosion calculation. API Recommended Inspection Schedule • Ultrasonic Inspection – Ultrasonic measurement of tank shell. – Inspections at 15 year intervals or possibly more frequent based on shell corrosion calculation. – Initial inspection in 5 years to establish a corrosion rate. – Corrosion rate may be estimated from tanks in similar service. API Recommended Inspection Schedule (Con’t) • Internal Inspection – Inspections at 20 year intervals or possibly more frequent based on tank bottom corrosion calculation. – Initial inspection in 10 years to establish a corrosion rate. – Corrosion rate may be estimated from tanks in similar service. Tank Maintenance Projects Typical Tasks • • • • • • Empty tank. Isolate. Clean and degas. Inspection blast of floor coating. API 653 inspection. Issue preliminary inspection report and develop list of maintenance/repair items. • Perform tank maintenance and repair work. Tank Maintenance Projects Typical Tasks (Con’t) • • • • • • Tank strapping Final blast Tank coating Final inspection Return tank to service Exterior painting or concrete/asphalt work (optional) • Final construction documentation Safe Work Practices • Safety is Everyone’s Job • Learn to Recognize Safe Work Practices Safe Work Permitting Procedure Heavy Tools are Lifted by Rope Tag Line not Hand Carried Confined Space Vapor Monitoring Radio Communication Leg Setting • The tank contractor will set the IFR legs from high position to low position to land the roof. • This requires a confined space entry from the manway on the fixed roof. Use Body Harness and Tripod for Confined Space Entry Tripods Must Have Leg Chains for Stability Pulley Must be Mounted and Secure Body Harness Must Be Properly Attached Lock Out / Tag Out • Lock out, tag out procedures are followed for piping and electrical. • Contractors verify that all valves have been closed and locked out. • Ensure that the terminal piping has been totally isolated (review terminal piping drawings). Plan Lockout/Tagout Gauge the Tank to Check that it is Empty Close, Lock, and Tag Valves to Isolate Electrical Lockout/Tagout Tank Valve Lockout Document the Valve Positions Tank Isolation • For all lines, a valve is removed and blinded to create an air gap. • Metal drip pans and vacuum truck are required when isolating the tank. • Bonding cables are required when removing valves. • 150 lb. blind flanges and new gaskets are required. • After blinding has been completed, the piping is visually inspected to ensure tightness. Inspecting Empty Vacuum Truck Prior to Use Bonding Cables and Metal Drip Pan Valve removal including bonding cables, respirators, gloves, fire extinguisher, metal drip pans and vacuum truck hose. Isolated Tank Valve with Air Gap Isolated Buried Line with Barricades Tank Degassing • Tank degassing is performed, when required, based on product type and location in accordance with EPA, State, or local air regulations. • Portable Thermal Oxidizers are most frequently used to handle the combustion throughput. IC engines or activated carbon systems can be used. • The units need to have the appropriate air permit and operate in accordance with the permits. Portable Thermal Oxidizer and Generator Degassing Unit Placed Outside of Tank Berm IC Engine Degassing Unit Temperature and Flow Monitoring is Typically Required by the Air Permit Once the Manway is Removed Plastic Sheeting is Place over it Immediately The Vapor Hose Penetrates the Plastic Sheeting Tank Cleaning • Proper placement of equipment to separate vapors from ignition sources. • Proper PPE (hard hats, rubber boots, gloves, suits, full body harness, etc.). • Enter with supplied fresh air. • Monitor vapors inside the manway away from inlet. • OSHA allows tank entry below 10% LEL for fresh air work; however, the goal is to be significantly lower. Hose Extends from Vacuum Truck to Tank Manway Vacuum Truck Exhaust Connected to Carbon Canister Manway Setup – Plastic Sheet, Fire Extinguisher, Confined Space Permits Intrinsically Safe Fan Mounted on Opposite Manway from Entrance PPE for Tank Entry Interior Appurtenances Removed to Drain Product Center Column Mouse Hole Drained of Product Marine Chemist Certifies the Tank as Gas Free The gas free certificate is posted over the manway. It may have certain restrictions to be aware of. Confined Space Access is Secured when the Contractor Leaves the Site Cribbing Blocks Installed to Support Roof Anti-Rotational Roof Support API 653 Tank Inspection Techniques • • • • • Magnetic Flux Exclusion (MFE) Ultrasonic Testing (UT) Vacuum Box Testing Dye Penetrant Testing Bottom Settlement Survey Calibration of Magnetic Flux Exclusion (MFE) Bottom Scanner Large MFE/UT Floor Scanner Scans within 2” of Lap Weld Seams Marking Corrosion Indications Circles – Topside Corrosion Square – Bottomside Corrosion Calibration of Smaller Hand Scanner Smaller Scanner in Congested Area Hand Scanner used at Corner Weld Remaining Floor Thickness is Marked in Area of Soil Side Corrosion Automated Ultrasonic Thickness Measurement used to “Prove Up” locations marked during MFE Scan Vacuum Box Testing of Corner Weld Vacuum Box Testing of Floor Plate Weld Seam Fluorescent Dye Penetrant Applied to Corner Weld Using Black Light to Find Defects Detected with Fluorescent Dye Bottom Settlement Survey Ultrasonic Testing of Tank Shell Ultrasonic Testing of Shell Reinforcement Pad and Nozzle Ultrasonic Testing of Internal Floating Roof Tank Repairs Tank Repairs • • • • • • • • Floor Patches and Plate Replacements Shell Repairs IFR Repairs Nozzles Seal Replacement Tank Valve Repairs Calibration and Repair of Gauging System Follow-up Testing Testing of Vapors Beneath Tank Floor Through Small Hole Drilled in the Floor Bottom Repair at Critical Zone Testing New Patch With Soapy Water Dye Penetrant Testing of Shell Nozzle Roof Drain Hose Inspection Replacing Seal Apron Fabric Fluorescent Testing Beneath IFR Inspecting the Penetrant Test Above the Roof to Search for Leaks Pressure Testing Pontoons Following Repairs Tank Interior Coating SPCC Compliance Purpose of SPCC Rule • Requirements help prevent oil discharges from reaching navigable waters or adjoining shorelines. • Certain facilities are required to develop SPCC Plans that describe equipment, workforce, procedures, and training to prevent, control, and provide adequate countermeasures to a discharge of oil. – Must comply with the rule requirements. – Must also implement the written Plan. What does the SPCC Rule Require? • Requires facilities to develop and implement a site-specific SPCC Plan to address: – Containment and procedures to prevent oil discharge (operating procedures, inspections & tank testing, training, etc.) – Control measures to keep an oil discharge from entering navigable waters (containment, drainage valves – Countermeasures to contain, clean up, and mitigate any oil discharge that affects navigable waters (spill response measures) • Performance-based rule designed to implement the Congressional policy of “no oil discharges” to waters of the United States Aboveground Petroleum Storage Tank Act (APSA) What is an Aboveground Petroleum Storage Tank? • 55 gallons or more. • Located substantially above ground. • Tanks are either UST or AST, but not regulated as both. • The volume for mixtures is based on the total tank capacity not the volume of petroleum in the mixture. APSA Exemptions • Two broad exemptions: – Exempt Tanks (HSC §25270.2(a)(1 – 6)) • Some exemption conditions (and compliance with those conditions) should be verified – Exempt Facilities (HSC §25270.4.5(b)) • Exempt only from APSA requirement to prepare and implement an SPCC Plan Tanks Exempted Under APSA • Boilers & pressure vessels • Waste & used oil tanks – Located at DTSC permitted hazardous waste TSD facilities (and listed on the permit), or specifically listed on a facility’s PBR Tiered Permit • • • • Crude oil production tanks Most oil-filled electrical equipment CUPA regulated USTs Transportation-related tank facility APSA (and SPCC Rule) Exempt Tanks • ‘Transportation-related facilities’ are not regulated under federal SPCC rules or APSA • Facilities are divided into three categories: – Transportation-related facilities (exclusively regulated by DOT / DOI) – Non-transportation-related facilities (not exclusively regulated by DOT / DOI) – Complexes (regulated by both) • Jurisdiction was established through a series of Executive Orders (EOs) and Memoranda of Understanding (MOUs) EOs and MOUs • Executive Order 11548 delegated responsibilities for regulating oil discharges (later superseded by E.O. 11735 and 12777). – EPA: Non-transportation-related facilities – DOT: Transportation-related facilities • EPA-DOT MOU (1971) defines transportation- and non-transportation-related. • DOT-DOI-EPA MOU (1994) establishes responsibilities for offshore facilities, including pipelines. Non-Transportation-Related Facilities (CUPA Jurisdiction under APSA) • Oil refining and storage facilities • Industrial, commercial, non-exempt agricultural, and public facilities that use and store oil • Waste treatment facilities • Loading areas and racks, transfer hoses, loading arms, and other equipment used to transfer oil in bulk to or from highway vehicles or railroad cars • Highway vehicles, railroad cars, and pipelines used to transport oil within confines of nontransportation-related facility Transportation-Related Facilities (DOT Jurisdiction) • Onshore and offshore terminal facilities, including transfer hoses, loading arms, and other equipment used to transfer oil in bulk to or from a vessel; including storage tanks and appurtenances for the reception of oily ballast water or tank washings from vessels • Transfer hoses, loading arms, and other equipment appurtenant to a non-transportation-related facility used to transfer oil in bulk to or from a vessel • Interstate and intrastate onshore and offshore pipeline systems • Highway vehicles and railroad cars that are used for the transport of oil Complexes (CUPA and DOT Jurisdiction) • A facility with both transportation-related and non-transportation-related activities is a “complex facility” and is subject to the dual jurisdiction of the CUPA under APSA and DOT. Underground Piping Associated with Aboveground Tanks • APSA does regulate buried piping. • The federal SPCC regulations contain requirements for buried piping at a regulated facility and APSA requires the implementation of the SPCC Plan for ASTs. APSA Regulated Piping • Must be connected to the tank. • APSA applies to: – Piping in the containment area. – Piping up to the first valve or flange outside the containment area. – If there is no containment, piping connected to the first flange or valve. • Federal SPCC rules for the facility may be broader and include piping not integrally related to the storage tank. APSA (SPCC) Compliance Verification • Written Plan review – All rule-required content (and format) – Facility-specific descriptions, procedures, etc. • Can be narrative, generic • Inspect for compliance with the detailed rule requirements – Whether adequately described in the Plan or not • Verifying the written Plan is consistent with field conditions • Verifying that the facility is implementing the Plan as written DOT Compliance Applicable DOT Regulations • Applicable to breakout tanks and pressure relief tanks at petroleum transportation facilities. • DOT views the tanks as part of the pipeline. • CFR Title 49 – Transportation. – Part 195 – Transportation of Hazardous Liquids by Pipeline. Applicable Sections of DOT Regulations for Tanks • 195.132 -- Design and Construction of Above Ground Breakout Tanks. • 195.307 -- Pressure Testing Above Ground Breakout Tanks (hydrostatic testing). • 195.432 -- Inspection of In-Service Breakout Tanks. • Subpart G -- Operator Qualification (OQ) Training Program. DOT Applicable Regulations Part 195.432 “Each operator must inspect the physical integrity of in-service atmospheric and low-pressure steel aboveground breakout tanks according to API Standard 653 (incorporated by reference, see §195.3). However, if structural conditions prevent access to the tank bottom, the bottom integrity may be assessed according to a plan included in the operations and maintenance manual under §195.402(c)(3).” Air Regulations Air Compliance • Air Compliance rules are confusing, complex, and sometimes conflicting. • This presentation will just provide a broad outline of rules. • Rule applicability determination depends on: – the year the tank was built, – tank volume, – vapor pressure of liquid. Clean Air Act (CAA) Regulations • Ozone Precursors (VOCs) – Title 1, the source is the individual tank. – NSPS Rule, 40CFR Part 60 • Subpart K – Effective 6/11/73 • Subpart Ka – Effective 5/18/78 • Subpart Kb – Effective 7/23/84 – Control Technology Guidelines (CTG), Reasonably Available Control Technology (RACT) rules Clean Air Act Regulations (Con’t) – Control Technology Guidelines (CTG), Reasonably Available Control Technology (RACT) rules. • • • • Applies to existing source in non-attainment areas. 1977 Fixed Roof Tank. 1978 EFR Tank. 1994 ACT for VOL Storage. Clean Air Act Regulations (Con’t) • Air Toxics – Hazardous Air Pollutants (HAPs Rule), Title III – NESHAPS (40 CFR Part 61). • These rules are specific to individual chemical in individual tanks. • Subpart Y is for Benzene. – NESHAPS (40 CFR 63) • Rule applies to all HAPs and the source is the entire facility. Clean Air Act Regulations (Con’t) – NESHAPS (40 CFR 63) – Continued • • • • • SOCMI HON Gasoline Distribution Petroleum Refineries Oil and Gas Production (a.k.a. – E&P MACT) Organic Liquids Distribution (a.k.a. – Old MACT)