Api rp 12r1 1997 (2008) scan (american petroleum institute)

Recommended Practice for Setting, Maintenance, Inspection, Operation, and Repair of Tanks in Production Service API RECOMMENDED PRACTICE 12R1 FIFTH EDITION, AUGUST 1997 REAFFIRMED: APRIL 2008 Recommended Practice for Setting, Maintenance, Inspection, Operation, and Repair of Tanks in Production Service Exploration and Production Department API RECOMMENDED PRACTICE 12R1 FIFTH EDITION, AUGUST 1997 REAFFIRMED: APRIL 2008 SPECIAL NOTES API publications necessarily address problems of a general nature With respect to particbe reviewed ular circumstances, local, state, and federal laws and regulations should API is not undertaking to meet the duties of employers, manufacturers,or suppliers to warn and properly train andequip their employees, and others exposed, concerning health and safety risks and precautions, nor undertaking their obligations under local, state, or federal laws Information concerning safety and health risks and proper precautions with respect to particular materials and conditions should be obtained from the employer, the manufacturer or supplier of that material,or the material safety data sheet Nothing contained in any API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or product covered by letters patent Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letters patent Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years Sometimesa one-time extension of up to two years will be added to this review cycle This publication will no longer be in effect five years after its publication date as an operative API standard or, where an extension hasbeen granted, upon republication Status of the publication can be ascertained from the API Authoring Department [telephone(202) 682-8000] A catalog of API publications and materialsis published annually and updated quarterly by API,1220 L Street, N.W., Washington, D.C.20005 This document was produced under API standardization procedures that ensure appropriate notification and participation in the developmental process and is designated as an API standard Questions concerning the interpretation of the content of this standard or comments and questions concerning the procedures under which this standard was developed should be directed in writing to the director of the Authoring Department (shown on the title page of this document), American Petroleum Institute, 1220 L Street, N.W., Washington, allany part of the material D.C 20005 Requests for permission to reproduce or translate or published herein should alsobe addressed to the director API standardsare published to facilitate the broad availability of proven, sound engineering and operating practices These standardsare not intended to obviate the needfor applying sound engineering judgment regarding whenandwherethese standardsshould be utilized The formulation and publication of API standards is not intended in any way to inhibit anyone from using any other practices Any manufacturer marking equipment or materials in conformance with the marking requirements of an API standard is solely responsible for complying with all the applicable requirements of that standard APIdoes not represent, warrant,or guarantee that such products in fact conform to the applicable API standard All rights reserved No part of this workmay be reproduced, storedin a retrieval system, or transmitted by any means,electronic, mechanical, photocopying, recording,or otherwise, without prior written permissionfrom the publisher Contact the Publisher; API PublishingServices, 1220 L Street, N W ,Washington,D.G 20005 Copyright O 1997 American Petroleum Institute COPYRIGHT American Petroleum Institute Licensed by Information Handling Services STD.API/PETRO RP LE'R1-ENGL L977 D 2 05bAOL5 711 W FOREWORD This API recommended practice is under the jurisdiction of the A P I Subcommittee on Standardization of Field Operating Equipment This fifth edition is a reformatted reissue of the 1991 fourth edition, which was reaffirmed by 1996 letter ballot This recommended practice provides guidelines for (a) setting and connecting of lease tanks at new tank battery installations and in other production and treating service, (b) maintaining and operating lease tanks, and (c) inspecting and repairing tanks constructed in accordance withA P I 12 series (B,D, F and P) standards Changes adoptedin the fourth editionof this recommended practice address both technical and environmenWsafety issues Major technical revisions included(a) development of tank inspection criteria and scheduling intervals, (b) adoption of repair recommendations, and (c) inclusion of a sectionaddressing spill preventioncontrolandcountermeasures (SEC) A numberoffederal, state, and local environmental and safety regulations affect the design and the operationof storage tanks utilized in production operations In preparingthis recommended practice, the following safety and environmental concerns were addressed: a Personal safety assurance b Prevention of catastrophic failure c Prevention of operational mishaps, suchas tank overflows d Minimization of the potential for leaks The environmental statutes and regulations affecting the operation of lease facilities are constantly evolving Individuals utilizing this document should review federal, state, and local regulationsto determine whether the practices recommended inthis document are consistent with current laws and regulations This recommended practice shall become effective on the date printed on the cover but may be used voluntarily from thedate of distribution API publications may be used by anyone desiring to so Every effort has been made by and reliability of the data contained in them; however, the the Institute to assure the accuracy Institute makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violationof any federal, state,or municipal regulation with whichthis publication may conflict be submitted to the directorof the Exploration Suggested revisions are invited and should and Production Department, American Petroleum Institute,1220 L Street, N.W., Washington, D.C 20005-4070 iii COPYRIGHT American Petroleum Institute Licensed by Information Handling Services CONTENTS page SCOPE REFERENCES DEFINITIONS RECOMMENDED PRACTICE FORSElTlNC AND CONNECTING TANKS 4.1 Setting of New or Relocated Tanks 4.2 Proper Measurement and Samplingof Oil in Tanks Used for Measurement and Providingfor Storage Efficiency 4.3 Delivery of Measured Quantities to Pipelinein Tanks Used for Measurement 4.4 TankIntegrity RECOMMENDED PRACTICE FORS A F E OPERATION AND SPILL PREVENTION OF TANKS 5.1 OperatingSafety 5.2 SpillPrevention RECOMMENDED PRACTICE FOR EXAMINATION, INSPECTION, AND MAINTENANCE OF TANKS 6.1General 6.2 Maintenance 6.3 Routine Operational Examination 6.4 External Condition Examination 6.5 Internal Condition Examination 6.6 InternaYExternal Inspections 6.7 Inspection Techniques 6.8 Shell Welds 6.9 Records 3 4 5 7 8 9 10 11 11 RECOMMENDED PRACTICE FORALTERATION OR REPAIR OF TANKS 11 7.1 vpes of Repairs 11 7.2 Preparation of Tank for Repairs 11 7.3 Minimum Thickness and Material Requirement of Replacement Shell Plate 11 7.4Weld Joints 11 12 7.5 Alteration of Tank Shells to Change Shell Height 7.6 Repair of Shell Penetrations 12 7.7 Hot Taps 12 7.8 Leak Detection on Bottom Replacement 12 12 7.9 Reconstructionof a Dismantled Tank 7.10 Required Hydrostatic Testing 12 13 7.1 Nameplates APPENDIX A RECOMMENDED QUALIFICATIONS FOR QUALIFIED 15 INSPECTORS AND COMPETENT PERSONS APPENDIX B EXAMPLE CALCULATIONOF VENTING REQUIREMENTS 17 APPENDIX C INDUSTRY OBSERVATIONS AND EXPERIENCES ON SHELL CORROSIONAND BRI'ITLE FRACTURE 19 V COPYRIGHT American Petroleum Institute Licensed by Information Handling Services ~ STD.API/PETRORPL2RL-ENGL L777 2 05bBOL7 59Ll Page APPENDIX D APPENDIX E APPENDIX F APPENDIX G APPENDIX H APPENDIX I CHECKLIST FOR EXTERNAL CONDITION EXAMINATION 21 CHECKLIST FOR INTERNAL CONDITION EXAMINATION 25 MINIMUM THICKNESS FORTANK ELEMENTS 29 CHECKLIST FOR EXTERNAL INSPECTION 31 37 CHECKLIST FOR INTERNAL INSPECTION FIGURES AND DIAGRAMS 43 Figures Example of Straight LineTank Battery Installation and Piping Configurations 45 Example of Small-Volume Shop-Welded Tanks Foundation and Connection Configurations 46 3A Example Tank Battery Installation Showing Dikeirewall and Example Piping Configuration 47 Dikepirewall 3B Example Tank Battery Installation Top View Showing and Example Piping Configuration 48 Corrosion Calculation Nomenclature 49 Tables Internal Tank Examinationhnspection Schedule External Tank Examinationhnspection Schedule F- Summary of Minimum Thickness forTank Elements vi COPYRIGHT American Petroleum Institute Licensed by Information Handling Services 8 30 m STD.API/PETRO RP 22RL-ENGL 7 m 0732290 b A O L A 420 m Recommended Practicefor Setting, Maintenance, Inspection, Operation, and Repair of Tanks in Production Service Scope References This recommended practice includes by reference, eitherin 1.1 This recommendedpracticeshould be considered as a total or in part,the most recent editionsof the following stanguide on new tank installations and maintenance of existing dards, unlessa specific editionis listed: tanks It contains recommendations for good practicesin (a) the collection ofwell or lease production, (b) gauging, (c) API delivery to pipeline carriers for transportation, and (d) other Spec 11N Lease Automatic Custody Transfer(LACT) production storage and treatment operations In particular, the Equipment spill prevention andexaminatiodinspectionprovisions of this recommended practice should be companion to the spill preSpec 12B BoltedTanks for Storage ofProduction vention control and countermeasures (SPCC) to prevent enviLiquids ronmental damage Spec 12D Field Welded Tanksfor Storage of Production Liquik This recommended practiceis intended primarily for appliSpec 12F Shop Welded Tanksfor Storage of Produccation to tanks fabricatedto API Specifications12F3, D,F, and tion LiquirLF P (sometimes called the API 12 series in this document) when Spec 12P Fiberglass Reinforced Plastic Tanks employed in on-land production service; but its basic princiBull D16-1974 Suggested Procedure for Development of ples are applicableto atmospheric tanks of other dimensions Spill Prevention Control and Counteneaand specifications when they are employed in similar oil and sures Plans gasproduction,treating,andprocessingservices.It is not W 0 Classtjication of Locations for Electrical applicable to refineries, petrochemical plants, marketing bulk Installationsat Petroleum Facilities stations,orpipelinestoragefacilitiesoperated by carriers RP 520 Sizing, Selection, and Installation of PresTanks fabricated to API Standard650 or its predecessor (API sure-RelievingDevicesinRejỵneries, Part Standard 12C) should be maintained in accordance with API 1, "Sizing and Selection" Standard 653 Std 650 Welded Steel Tanksfor Oil Storage 1.2 This documentrecommendsmaintenancepractices Std 653 Tank Inspection, Repair; Alteration, and Reconstruction basedontheestimated corrosion rate life ofvarioustank components Corrosion ratelife of tank components willvary Std2000 Venting Atmospheric and Low-Pressure widely with location, environment, service, type of fluid, and and Storage Tanks: Nonrefrigerated Refrigerated corrosion mitigation techniques elected by the ownedoperator Recommendations for specific corrosion mitigation techStd 2003 Protection Against Ignitions Arising Outof niques are not within the scope of this document For such Static, Lightning,and Stray Currents recommendations, see publications of the National AssociaPubl 2009 SafeWelding and CuttingPracticesin tion of CorrosionEngineers (NACE) (see Section 2) Refineries,GasolinePlants, and Petrochemical Plants 1.3 This documentcontainssomespecificsafetyrecomRP 2015 Safe Entryand Cleaning of Petroleum Stormendations applicable to tanks For complete safety recomage Tanks,PlanningandManagingTank mendations, see publications of the API Committee on Safety Entry From Decommissioning Through and Fire Protection Recommissioning Publ 2207 Preparing Tank Bottom for Hot Work 1.4 The schematic drawings included in this publication are Publ 2210-1982 Flame Arresters for Vents of TanỈ Petroexamples only of some features described in the document leum Products Numerous variations in piping systems andtank components Environmental Guidance Document: are knowntogive satisfactoryservice.Unusualgrades of Onshore Solid Waste Management in crude, particularly heavier grades, may cause the ownedoperExploration and Production Operations ator to elect other equally satisfactory practices MPMS, Chapter 6.l-"LeaseAutomatic Custody Transfer (LACT) Systems" 1.5 Leaseautomaticcustodytransfer(LACT)operations are covered in API Specification 1lN, and in the API Manual MPMS, Chapter 8.1-"Manual Sampling of Petroleum Measurement Standards, Chapter 6.l of Petroleum and Petroleum Products" COPYRIGHT American Petroleum Institute Licensed by Information Handling Services API RECOMMENDED PmcncE 12R1 NACE' RP-01-78 Design, Fabrication, and Surface Finish of Metal Tanks and Vessels to be Lined for Chemical Immersion Service RP-05-75 Design, Installation, Operation,andMaintenance of Inteml CathodicProtection System in Oil Treating Vessels SPEz Petroleum Handbook 3.10conditionexamination(internallexternal): A review of history and physical observation of a tank and its adjacent equipmentby a competent person 3.1 corrosion rate: Estimated or measured rateof metal less due to corrosion 3.12 corrosion rate life: The corrosion rate life of a tank is definedas follows: Corrosion Rate Life (years) = Definitions (Tcurrent - Tminimum corrosion rate (inchedyear) Where: For the purposesof this standard, the following definitions apply 3.1 alteration: Anywork doneonatankwhichdeparts from the original design and includes changes in size, shape, or structural members 3.2 applicable standard for alteration: The applicable standard for alterationis the latest revision of the original API specification 3.3applicablestandardforinspectionorrating: Any tank coveredby this recommended practice may be rated or inspected eitherby the original specification under which it was built or, at the option of the ownedoperator, the latest revision of the same specification 3.4 applicable standard for repair: For design, materials, workmanship, and testingof any new piece or part added to the tank, the applicable standard is the latest revision of the original API specification For original parts, see applicable standard for inspection or rating T,,,, = the thickness, in inches, measured at the timeof inspection for the limiting section used in the determination Tmhim,,,,, = the minimum allowable thickness, in inches, Ïor the limiting sectionor zone 3.13 frangible deck A tank in which the roof deck is designed to fail under pressure loading For design criteria, be seeAPISpecification 12D Frangibledecksmayalso called weak seamconstruction 3.14hottap: Aprocedureforinstallingappurtenances penetrating the shellor deck of a tank that is in service 3.15 inspection (internallexternal): A detailed inspection to appraise the suitability for service of a tank including sufficient measurements to estimate its remaining corrosion rate life Inspections shallbe done only by a qualified inspector Inspections are categorized in the following four ways: a Scheduled inspections: Routine inspections performed at intervals specified by the ownedoperator based on the corro3.5 atmospheric pressure tank:A tank designed for sion rate life of the class of tanks internal pressures up to, but not exceeding,2% pounds per b Unscheduled inspections: Inspections prompted by results square inch gauge in the vapor space above the contained obtained from a condition examination or by an operational liquid alert c Externalinspections:Inspectionsmadewithouthuman 3.6 change in location: Any relocation within or or visual inspection of internal parts entry between fields, units, or plants d.Internalinspections:Inspectionswhichrequirehuman 3.7 change in service: A change from previous operating entry or visual inspection of internal parts conditions involving different properties of the stored product, such as specific gravity, corrosivity, temperature, or pressure 3.16 operational alert:Any operational malfunction of a tank which may signal a potential deterioration 3.8classof tank Classificationfora group oftanks 3.17 owner/operator: The legal entity having both conaccording to service,coatings,corrosionmitigationtechtrol of and/or responsibility for operation and maintenance of niques, locale, and setting an existing storage tank 3.9competentperson: Aresponsibleindividual,designated by the owner/operator, who is capable of recognizing existing and predictable hazards Recommended qualifications for a competent person are given in Appendix A of this document 'NACEInternational, P.O.Box 218340, Houston, Texas 77218 Engineers, P.O Box 833836, Richardson, Texas *Society of Petroleum 75083-3836 measurement employ and specifications COPYRIGHT American Petroleum Institute Licensed by Information Handling Services API 3.18 potentialdeterioration: Potentialdeterioration is indicated by a warning sign of deterioration This warning may be obtained from corrosion coupons or fluid analysis and may indicate the need for a condition examination oftank a 3.19 qualified inspector: An individualdesignated by the owner/operator has the technical to read and understand RECOMMENDED PRACTICE FOR SElTlNG, MAINTENANCE, INSPECTION, OPERATION, AND REPAIROFTANKS IN PRODUCnON SERVICE toolsrequired to evaluatetechnicalcompliancewiththe specifications Recommended qualifications are presented in Appendix A c Ensure that any fluids leaking through the bottom of the tank will drain to the perimeterof the tank rather than penetrate the soil and/or groundwater 3.20 reconstruction: Theworknecessarytoreassemble a tank that has been dismantled and relocated to a new site 4.1.5 The foundation sub-base shouldbe well-graded, compacted soil If the soil is not sufficiently impermeable to prevent migration of fluids into soils below the tank, a plastic sheet or other barrier to liquid shouldbe placed over thesubbase to provide an impermeable barrier Thesubbase should be raised at the center of the tank to facilitate drainage toward the perimeter Drainage should be providedawayfrom the tank 3.21 roufine operational 'examination: visual A examination made by operators or technicians during their routine attendance at a facility to determine the occurrence of an equipment malfunction or a tank leak No written record of a routine operational examination need be kept unless an equipment malfunctionor tank leakis detected Recommended Practicefor Setting and Connecting Tanks 4.1 SElTlNG OF NEW OR RELOCATEDTANKS 4.1.1 The location of tanks should be selected after consideringoperationalneeds, canier requirements,prevailing winds,environmentalandsafetyconditions,andalllocal, state, and federal regulations governing such locations 4.1.2 Tanksshouldbeconstructedinaccordancewiththe following: a API Specification 12B b API Specification 12D c API Specification 12F d M I Specification 12P 4.1.3 Tank spacingshouldcomplywithlocal,state,and federal regulations In general, tanks should be located in a straight lineas shown in Appendix I, Figurel The minimum shell-to-shell spacing for personnel access betweentanks is feet (91 centimeters) with spacing adjusted so that pipe headers can be prefabricated to standard patterns If tanks are set with pipeline connections facing one another, sufficient space shouldbe provided between tank shells to safely afford proper inspection and operation of valves and other appurtenances Personnel access to all piping connections for operations, inspection, and maintenance should be considered in the design Appendix I, Figure shows examples of small shop welded tanks with foundation and connection configurations AppendixI, Figures 3A and 333 show examples of battery installations with piping configurations when dikedfirewalls are used The recommendations for barriers, valves, drains, vents, and the like shown in these figures are discussed in more detail in the remainder of this recommended practice 4.1.4 Thefoundation of atankshouldbedesignedand installed to the following: a Support the tankso that it will remain level and elevated b Drain rainwater away from the base and bottom of the tank so as to keep the underside as dry as possible COPYRIGHT American Petroleum Institute Licensed by Information Handling Services 4.1.6 The foundation base should be made of gravel, shell, sand, concrete, or other material that facilitates drainage and provides structural support A retainer ring may be used to confine loose material and to facilitate detection of liquid drainage from below the tank 4.1.7 The foundation should be level at the circumference ofthetankandgreaterthanthetankdiameterunlessa retainer ring isused Level bases are required for tanks which are used for measurement of produced liquids 4.1.8 Ifaretainerring is usedandit doesnotextend beyond the diameter of the tank, small seep holesor tell-tale devices shouldbe provided as a means for visible leak detection and drainage 4.2 PROPER MEASUREMENT AND SAMPLING OF OIL INTANKS USED FOR MEASUREMENT AND PROVIDING FOR STORAGE EFFICIENCY 4.2.1 All lease tanks should be set and maintained as level and as free of distortion as possible Inlet and outlet connections shouldbe located so as to cause level settlementof basic sediment during filling or draining 4.2.2 The main hatch (thiefor gauge) shouldbe of standard size as shown in API 12 Series tank specifications, and should be located in the roof deck adjacent to the top chime directly above the pipeline outlet except in the following situations: a Where a connection is provided with an upturned ell or other appurtenance inside the shell of the tank b Where wet-oil (oil with basic sediment and water content above pipeline specifications) is encountered c Where sample cocksor LACT units are used for sampling In the cases described in 4.2.2, Items a, b, and c, a minimum of feet (1.8 meters) circumferentially should separate the main hatch and the pipe outlet If an auxiliary hatch is necessary as a second point to measure the settled basic sediment and water content, it should be located diametrically across from the main hatch Gauging or striking plates should be installed at or near the if the innage bottom chime, directly below the gauging hatch, ~ STD.API/PETRO RP ~~ LZRL-ENGL L971 m 2 0568044 m API RECOMMENDED PRACTICE 12R1 34 Checklist for External Inspection (Continued) Condto i nof Insulation Protectionof Insulated Tanks, Shell Material (HdesITears) Number & Location Seal AroundRoof/ShellJoint (Separations) Number& Location ~~~ ~ ~ ~~ _~ _ _ _ _ ~ ~ ~~~~ Seal Around Appurtenances (Separations) Number & Location External Corrosion Tank BdtrRivets Corrosion YEW0 YESMOM If Yes, Number & Location Tank Fiberglass Delaminated YEWNOMA If Yes, Number & Location Results of Ultrasonic Measurements In Vapor Zone In Liquid Zone Tank Roof Deck Hatches SecurelyClosed Roof Patches YEWNOMA Y ESMO If Yes, Number & Location Roof Deck AbnormalitieslDistorlitions YESMO If Yes, Number & Location Visible Signsof Holeskeaks If Yes, Number & Location COPYRIGHT American Petroleum Institute Licensed by Information Handling Services YEW0 RECOMMENDED PRACTICEFOR SElTlNG.MAINTENANCE, INSPECTION OPERATION.AND REPAIR OFTANKS IN PROOUCTIOSERVI N CE 35 'Checklist for External Inspection (Continued) Deck External Corrosion None, Minimal, Moderate, Severe off of Deck YEWNOAdequate Condition of External Coating of Uninsulated Deck, Holes, Disbonding, Deterioration, Discoloration Number & Location Condition of Insulation Protection of Insulated Deck Roof Material (Holeflears) Number & Location & Location Seal Around Appurtenances (Separations) Number ~ ~~ ~ ~~~ ~~ Results of Ultrasonic Thickness Measurements (Compare to OriginalValues) Results of Hammer Tests Appurtenances Thief Hatch8, Vent Valves Seal Properly YESNO Thief Hatch Opens FreelyW/O Plugging YEW0 Vent Valve Operational YES/NO Sample & Drain Valves Leak YES/NO Inspect Nozzle Seams for Cracks YEWNO Piping, and the like, Properly Supported Off of Tank YEWNO Tank Shell Dimplingat Connections YESNO Metal Appurtenance BondedOR Gas Blanket Operational on Fiberglass Tank Stairways &Walkways Structurally Sound COPYRIGHT American Petroleum Institute Licensed by Information Handling Services YES/NO/NA YESNO API RECOWENDEDPRACTICE12R1 36 Checklist for External Inspection (Continued) Miscellaneous cathodic Protecthl operation*tentiai Adequate YEWNOMA Vapor Recavery System Operational YESINOM Gas Blanket System Operational Containment Dikes and/or Liner Maintained& Adequate Size YESINOM Proper Warning Signs inPlace Automatic Level IndicatorOperational& Accurate (Compare to Hand Gauge Level) Tank Area Clean of Trash & Vegetation Recommended Futute Action COPYRIGHT American Petroleum Institute Licensed by Information Handling Services Y€S/NO/NA YESNO Y€S"A YEWNO APPENDIX H-CHECKLIST FOR INTERNAL INSPECTION 37 COPYRIGHT American Petroleum Institute Licensed by Information Handling Services RECOMMENDEDPRACTICE FOR SElTING, MAINTENANCE,INSPECTION, OPERATION, AND REPAIR OFTANKS IN PRODUCTION SERVICE 39 Checklist for Internal Inspection Identification Tank Designation: Size: Date of Inspection: Measured M Estimated Liquid Level: Contents: Pre-Inspection Tank Properly Cleaned YEW0 Tank Atmosphere Properiy Tested YEW0 Tank Properly Isolated YEW0 Tank Structurally Sound YES/NO Confined Space Entry Procedure Implemented YESMO Tank Bottom Floor Adequately Supported (Limited Voids Under Floor Plate) YESIN0 Drainage If Low Spots Exist, Number& Location Floor Sloped for Adequate YESMO Plate Buckling/Deflection Acceptable YEW0 Visually Inspect& Record Plate &Weld Condition Inspect ShelUBottom Seam & Location Condition of Internal Coating (Holes, Disbonding, Deterioration) Number Inspect & Describe Pitting Appearance (Depth, Sharp Edged, Lake Type, Dense, Scattered) Results of Ultrasonic Thickness Measurement COPYRIGHT American Petroleum Institute Licensed by Information Handling Services API RECOMMENDED PwcncE 12R1 40 Checklist for Internal Inspection (Continued) Results of Vacuum Tests Results of Penetrant Dye Tests Results of Hammer Tests Results of Other Testing (MagneticFlux Leakage, Acoustical Emission, andso forth) In Earthquake Zones & 4, Roof Supports Restrained From Horizontal Movement Only (Not Welded Identify Areas to Be Repalred Number & Location Tank Shell Visually Inspect & Record Plate &Weld Conditions Number& Location Conditionof Internal Coating (Hdes,Dishding, Deterioration) Number& Location Survey Shell to Check Plumb & Roundness ~~~ Results of Ultrasonic Thickness Measurementsin Vapor Zone COPYRIGHT American Petroleum Institute Licensed by Information Handling Services to Floor) YESMO ~~ ~ Checklist for Internal Inspection (Continued) in Liquid Zone Identify Areas to Be Repaired Number& Location Tank Roof Inspect & Describe Pitting Appearance (Depth, Sharp Edged, Lake Type, Dense, Scattered) Conditions of Internal Coating.(Holes, Disbonding, Deterioration) Number & Location Visually Inspect& Record Plate&Weld Conditions Number& Location Results of Ultrasonic Thickness Measurements Check Roof Support Columnsfor: Thinning in Vapor Zone Thinning in Liquid Zone Drain Opening ln Bottom of Pipe or Concrete Filled Proper Attachmentto Roof & Bottom Inspect Girders& Rafters for Thinning Glrders & Rafters Properly Secured Identify Areas to Be Repaired Number& Location COPYRIGHT American Petroleum Institute Licensed by Information Handling Services YESNO 42 PRAcncE RECOMMENDED API 12R1 Checklist for Internal Inspection (Continued) Appurtenances Visually Inspect AllSeals & Gaskets Inspect & Service PressureNacuum HatchesNalves Inspect Gauge Well (if Existing) Inspect Internal Reinforcing Pads(i Existing) for Cracks Inspect Internal Nozzle Seams for Cracks, Corrosion, and the like Inspect Diffusers& Rolling Systems Inspect Swing Lines Inspect Wear Plates Recommended Future Action COPYRIGHT American Petroleum Institute Licensed by Information Handling Services APPENDIX I-FIGURES AND DIAGRAMS COPYRIGHT American Petroleum Institute Licensed by Information Handling Services E COPYRIGHT American Petroleum Institute Licensed by Information Handling Services 46 COPYRIGHT American Petroleum Institute Licensed by Information Handling Services API RECOMMENDED PRACTICE 12R1 S T D A P I / P E T R O RP L R L - E N G L L997 m 2 0568055 T B m RECOMMENDED PRACTICE FOR SElTlNG MAINTENANCE, INSPECTION OPERATION AND REPAIR OFTANKS IN PRODUCTION SERVICE -P P h -"""""L COPYRIGHT American Petroleum Institute Licensed by Information Handling Services k 47 API RECOMMENDED PwcncE 12R1 48 \ \ L COPYRIGHT American Petroleum Institute Licensed by Information Handling Services -No personnel access_I_ Personnel access I T.' corroded T?corroded ' Liquid height T I Ts3 corroded H 4T : I T', II Rafters if any Il \ 2rd ring D thickness corroded L 1st ring 1' critical shell f / corroded Tb* ring annular 1' critical Figure 4-Corrosion Calculation Nomenclature COPYRIGHT American Petroleum Institute Licensed by Information Handling Services Illly eCenter pole any if corroded thicknessa- Design corroded Tb' 0.A i" UIU \ Additional copies available from API Publications and Distribution: (202)682-8375 Information about API Publications, Programs and Services is available on the World Wide Web at: httpi/www.api.org American Petroleum Institute 1220 L Street, Northwest Washington, D.C.20005-4070 202-682-8000 COPYRIGHT American Petroleum Institute Licensed by Information Handling Services ~ ~ ~ ~~~ ~~ ~~ Order No G12R15