TOXIC SUBSTANCE STORAGE TANK CONTAINMENT ASSURANCE AND SAFETY PROGRAM GUIDELINES FOR APPLICATION OF TECHNICAL CODES FOR HAZARDOUS MATERIALS STORAGE TANKS HEALTH AND MENTAL HYGIENE STATE OF MARYLAND DEPARTMENT OF HEALTH AND MENTAL HYGIENE OFFICE OF ENVIRONMENTAL PROGRAMS SCIENCE AND HEALTH ADVISORY GROUP MARYLAND DEPARTMENT OF ------- Tt> bw.Z .£3(* )CIBS MO-489-D456 TOXIC SUBSTANCE STORAGE TANK CONTAINMENT ASSURANCE AND SAFETY PROGRAM: GUIDELINES FOR APPLICATION OF TECHNICAL CODES FOR HAZARDOUS MATERIALS STORAGE TANKS PREPARED UNDER U.S. ENVIRONMENTAL PROTECTION AGENCY GRANT NUMBER CS807904010 AUTHORIZED BY SECTION 28 OF THE TOXIC SUBSTANCES CONTROL ACT BY: Ecology and Environment, Inc. Buffalo, New York and Whitman, Requardt and Associates Baltimore, Maryland FOR: STATE OF MARYLAND DEPARTMENT OF HEALTH AND MENTAL HYGIENE OFFICE OF ENVIRONMENTAL PROGRAMS SCIENCE AND HEALTH ADVISORY GROUP 201 WEST PRESTON STREET BALTIMORE, MARYLAND 21201 SEPTEMBER 1983 ------- DISCLAIMER This report has been reviewed by the State of Maryland Department of Health and Mental Hygiene, Office of Environmental Programs, and approved for publication. Approval does not signify that the contents necessarily, reflect the views and policies of the Department of Health and Mental Hygiene, or the United States Environmental Protection Agency, nor does mention of trade names or commercial products consti- tute endorsement or recommendation for use. Because hazardous materials vary widely in their characteristics and in the manner in which they should be stored, the material con- tained within this Manual can serve only as a guide. It is the responsibi1ity of the storage facility owner to seek the assistance of appropriately qualified professionals with the necessary skills to design a storage system which can be used safely, and which provides the necessary measures for public and environmental protection. i i ------- ACKNOWLEDGEMENTS Development of this document was accomplished with the assistance of an advisory committee representing the following State of Maryland agencies: 0 Department of Health and Mental Hygiene Office of Environmental Programs - Air Management Adminis- tration - Waste Management Admin- i stration - Science and Health Advisory Group Department of Public Safety and Correctional Services State Fire Marshall's Office t Department of Natural Resources Water Resources Adminis- tration Department of Licensing and Regulation Maryland Occupational Safety and Health Administration also, Maryland Casualty Company, Baltimore We also wish to express our appreciation for the guidance and direction provided throughout this project by Mr. K.K. Wu, Toxics Integration Coordinator, U.S. Environmental Protection Agency, Region III, Philadelphia, Pennsylvania. i i i ------- TABLE OF CONTENTS Section Page 1 INTRODUCTION 1-1 2 CODES APPLICABLE TO STORAGE TANKS 2-1 2.1 ATMOSPHERIC TANKS 2-1 2.2 LOW-PRESSURE TANKS 2-6 2.3 HIGH-PRESSURE TANKS 2-6 2.4 STORAGE TANK CONSTRUCTION MATERIALS 2-7 3 USE AND INTERPRETATION OF TECHNICAL CODES 3-1 3.1 API STANDARDS AND SPECIFICATIONS 3-2 3.2 NATIONAL FIRE CODES 3-2 3.3 ASTM STANDARDS 3-3 3.4 AS ME BOILER AND PRESSURE VESSEL CODE 3-4 4 CONCLUSIONS AND RECOMMENDATIONS 4-1 v ------- LIST OF TABLES Table 2-1 Major Technical Codes Applicable to Storage Systems vi i ------- SECTION 1 INTRODUCTION Over the years, technical codes have been developed by independ- ent tradn organizations to standardize materials, design, fabrication, and inspection methodologies in. a variety of industrial areas. These codes delineate acceptable and desirable practices an industry should follow to attain uniform quality and safety in its operations. The general purpose of such codes is to ensure reasonable protection of life and property, and to adequately limit in-service product deteri- oration, so as to provide a reasonably long and safe period of useful- ness. Adherence to such codes is not mandatory, however, unless they are specially adopted by a regulatory body. Technical codes are generally developed by consensus of a commit- tee within an independent or industrial organization. Such committees typically are composed of technically qualified representatives of producers, users, and general interest groups. When codes are adopted by a regulatory agency, representatives of that agency often are invited to participate in committee actions to ensure correspondence between the technical code and other regulations in effect in their jurisdiction. Engineers, designers, manufacturers, and inspectors should determine if the applicable state and local regulations differ from the technical codes they are based upon. The technical codes promulgated by an organization take many forms which are variously called standards, specifications, or recom- mended practices. Standards, a term often used interchangeably with "code," is an inclusive term that designates the specifications, methods, definitions, classifications, or practices adopted by an organization. Standards are generally regarded as mandatory criteria with which a producer must comply if the product is to bear the organ- ization's seal of approval. Specifications are a precise statement of the requirements to be satisfied by a material or product, and the procedures to ensure adherence to those requirements. The specifica- tions are usually expressed numerically and incorporated directly or by reference in the technical standards. Recommended practices are procedures and specifications which are advisable in nature, not man- datory for gaining the sponsoring organization's approval. Because the codes may be either more or less restrictive than needed for certain applications, their use is generally voluntary, and the mere existence of technical codes or standards does not preclude anyone from using, purchasing, manufacturing, or marketing products or procedures which do not conform to the standards. Frequently, techni- cal codes will form the basis for regulatory control of a particular class or aspect of industry. In such cases a given technical code forms the standard which a governmental agency will impose through a 1-1 ------- regulatory process. Commonly the agency will also adopt a program of licensing or inspection to insure that the provisions of those codes adopted through regulation are being met. Although technical codes cannot be construed as being binding in a regulatory or legal sense unless specifically adopted by a regulating agency, they may be a pre- requisite to obtaining adequate insurance coverage. 1-2 ------- SECTION 2 CODES APPLICABLE TO STORAGE TANKS Ideally the application of technical codes should commence at the storage system design stage. Several codes detail the design and fabrication of storage tanks, and these constitute the acceptable industrial standards. These codes are typically applicable to spe- cific tank types, tank contents, construction materials, construction methods, or types of appurtenances. Since there is much variability and overlap among the codes, design and inspection engineers should consult individual codes to determine their specific scope and limita- tions. Many of the major technical codes applicable to various aspects of storage system design are listed in Table 2-1. This table indicates the title and number of codes, and the types of tanks to which they apply. 2.1 ATMOSPHERIC TANKS A series of specifications for steel atmospheric storage tanks has been developed by the American Petroleum Institute (API). These include: API Spec. 12 B, Bolted Production Tanks; API Spec. 12 D, Large Welded Production Tanks; and API Spec. 12 F, Small Welded Production Tanks. Standards for aluminum tanks are covered by ANSI (American National Standards Institute) Standard B 96.1. Many standards dealing with water handling and storage have been developed by the American Water Works Association (AWWA). Although these tanks are intended for water storage, they are applicable for storage of other liquids as well. Their standards include: AWWA D 100-67 - Standard for Steel Tanks, Standpipes, Reser- voirs, and Elevated Tanks for Water Storage; AWWA D 101-53 - Standard for Inspecting and Repairing Steel Tanks, Standpipes, Reservoirs, and Elevated Tanks for Water Storage; and AWWA D 102-64 - Standard for Painting and Repainting Steel Tanks, Standpipes, Reservoirs, and Elevated Tanks for Water Storage. Underwriters Laboratories (UL) has developed standards which overlap those of API, but include tanks too small for API standards. 2-1 ------- Table 2-1 MAJOR TECHNICAL CODES APPLICABLE TO STORAGE SYSTEMS Applicable Organization - Code No. Title Tank Types API Spec. 12B Bolted tanks for storage of production liquids A API Spec. 120 Field welded tanks for storage of production liquids A API Spec. 12F Shop welded tanks for storage of production liquids A API RP 12RI Setting, connecting, maintenance, and operation-of lease tanks A API Std. 510 Pressure vessel inspection code L, H API RP 520 Design and installation of pressure-relieving systems in refineries H API RP 521 Pressure relief and depression systems H API Std. 526 Flanged steel safety relief valves L, H API Std. 620 Design and construction of large welded, low-pressure storage tanks L API Std. 650 Welded steel tanks for oil storage A API Publ. 1587 Waste oil round-up A API Publ. 1604 Abandonment or removal of used underground service station tanks A API Bull. 1615 Installation of underground petroleum storage systems A API Publ. 1621 Bulk liquid stock control at retail outlets A API Bull. 1623 Bulk liquid loss control in terminals and depots A API Bull. 1628 Underground spill clean-up manual A, L, H API Std. 2000 Venting atmospheric and low-pressure storage tanks A» L API RP 2001 Fire protection in refineries A, L, H API RP 2003 Protection against ignitions arising out of static, lightning, and stray currents A, L, H API Publ. 2009 Safe practices in gas and electric cutting and welding in refineries, gasoline plants, cycling plants, and petrochemical plants A, L, H API Publ. 2013 Cleaning Mobile tanks in flammable or combustible liquid service A API Publ. 2015 Cleaning petroleum storage tanks A, L, H API Publ. 2015A A Guide for controlling the lead hazard associated with tank cleaning and entry A, L, H API Publ. 2023 Safe storage and handling of petroleum-derived asphalt products and crude oil residues A API Bull. 2202 Dismantling and disposing of steel from tanks which have contained leaded gasoline A 2-2 ------- Table 2-1 (Cont.) Applicable Organization - Code No. Title Tank Types API Publ. PSD- Preparing tank bottoms for hot work A, L, H 2207 API Std. 2510 Design and construction of LPG installations at L, H marine terminals, natural gas plants, refineries, and tank farms API Bull. 2519 Use of internal floating covers and covered floating A roofs to reduce evaporation loss API Guide for Inspection of Refinery Equipment: Ch. II - Conditions causing deterioration or A, L, H failures Ch. Ill - General preliminary and preparatory work A, L, H Ch. IV - Inspection tools A, L, H o Ch. V - Preparation of equipment for safe entry A, I, H and work Ch. VI - Pressure vessels L, H ¦ Ch. XI - Pipes, valves, and fittings A, L, H Ch. XII - Foundations, structures, and buildings A, L, H Ch. XIII - Atmospheric and low-pressure storage A, L tanks ¦ Ch. XIV - Electrical systems A, L, H Ch. XV - Instruments and control equipment A, L, H Ch. XVI - Pressure relieving devices A, L, H a Ch. XVII - Auxiliary and miscellaneous equipment A, L, H Appendix - Inspection of welding A, L, H API Guide for Follow-up Inspection of Interior Tank A, L, H Coatings NFPA 11 Foam extinguishing systems A, L, H NFPA 11A High expansion foam systems A, L, H NFPA 11B Synthetic foam and combined agent systems A, L, H NFPA 12 Carbon Dioxide extinguishing systems A, L, H NFPA 12A Halogenated fire extinguishing agent systems A, L, H NFPA 16 Installation of foam-water sprinkler systems and A, L, H foam-water spray systems NFPA 17 Dry chemical extinguishing systems A, L, H NFPA 30 Code for flammable and combustible liquids A, L, H NFPA 43A Liquid and solid oxidizing materials A, L, H NFPA 49 Hazardous chemical data A, L, H 2-3 ------- Table 2-1 (Cont.) Applicable Organization - Code No. Title Tank Types NFPA 58 Storage and handling of LPG I, H NFPA 59 Storage and handling of LPG at utility gas plants L, H NFPA 68 Explosion venting A, L, H NFPA 69 Explosion preventing systems A'. L, H NFPA 70 National electrical code A, L, H NFPA 72A Installation, maintenance, and use of local protec- tive signaling systems A, L, H NFPA 72B Installation, maintenance, and use of auxiliary pro- tective signaling systems L, H NFPA 72C Installation, maintenance, and use of remote pro- tective signaling systems A, L, H NFPA 72D Installation, maintenance, and use of proprietary protective signaling systems A, L, H NFPA 72E Automatic fire detectors A, L, H NFPA 77 Recommended practice on static electricity A, L, H NFPA 78 Lightning protection code A, L, H NFPA 231 General indoor storage A NFPA 231A General outdoor storage A NFPA 321 Classification of flammable and combustible liquids A, L, H NFPA 325M Fire hazard properties of flammable liquids A, L, H NFPA 327 Cleaning small tanks and containers A, L, H NFPA 329 Underground leakage of flammable and combustible liquids A, L, H NFPA A19M Code for explosive materials A, L, H NFPA 495 Identification of fire hazards of materials A, L, H NFPA 1221 Installation, maintenance, and use of public fire service communications A, L, H NFPA Fire Protection Guide on Hazardous Materials ASME Boiler and Pressure Vessel Code: o Section II - Materials specifications o Section V - Nondestructive examination o Section VIII - Pressure vessels o Section X - FRP Pressure vessels L, H AWWA D100- 67 Standard for steel tanks, standpipes, reservoirs, and elevated tanks for water storage A AWWA D101- 53 Standard for inspecting and repairing steel' tanks, standpipes, reservoirs, and elevated tanks for water storage A 2-4 ------- Table 2-1 (Cont.) Organization - Code No. Title Applicable Tank Types AWWA D102- Standard for painting and repainting steel tanks, A 64 standpipes, reservoirs, and elevated tanks for water storage ACI Guide for Protection of Concrete Against Chemical A, L, H Attack by Means of Coatings and Other Corrosion-Resistant Materials ACI Manual of Concrete Practices A, L, H ACI 344 Design and construction of circular prestressed A, L, H concrete structures AIA Fire Prevention Code A, L, H NACE RP-01- Control of external corrosion on underground or A, L, H 69 submerged metallic piping systems NACE No. 1 - Surface preparation for tank linings A, L, H NACE No. 2 Surface preparation for some tank linings and heavy A, L, H maintenance NACE No. 3 Surface preparation for maintenance A, L, H NACE No. 4 Surface prepartion for very light maintenance A, L, H NACE RP-03- Method for lining lease production tanks with coal A, L, H 72 tar epoxy SSPC 5-63 White metal blast A, L, H SSPC 10-63 Near-white metal blast A, L, H SSPC 6-63 Commercial blast A, L,'H SSPC 7-63 Brush off blast A, L, H LEGEND: Organization: API = American Petroleum Institute NFPA r National Fire Protection Association ASME = American Society of Mechanical Engineers AWWA = American Water Works Association ACI = American Concrete Institute NACE = National Association of Corrosion Engineers SSPC = Steel Structures Painting Council Code Number: A numerical designation assigned to a code, etc., by the promulgating organization. Spec = specification RP = recommended practice Std = standard Publ. = publication Bull. = bulletin Applicable Tank Types: A = Atmospheric L = Low Pressure H = High Pressure Source: Ecology and Environment, Inc., 1983. 2-5 ------- UL standards do not provide as much detail as API standards, and therefore put more responsibility on the designer to obtain guidance from other professional reference standards and guidelines. Two UL standards applicable to hazardous materials storage are: UL 58 - Steel Underground Tanks for Flammable and Combustible Liquids; and UL 142 - Steel Aboveground Tanks for Flammable and Combustible Liquids. Other standards related to atmospheric tanks include: ANSI B31.3 - Petroleum Refinery Piping Code; API Standard 650 - Welded Steel Tanks for Oil Storage; and API Standard 2000 - Venting Atmospheric and Low-Pressure Stor- age Tanks. 2.2 LOW-PRESSURE TANKS Vertical, cylindrical tanks with domed roofs which operate at pressures slightly above atmospheric pressure can be built according to API Standard 650. However, for tanks with more substantial operat- ing pressures, up to 15 psig, API Standard 620, Recommended Rules for Design and Construction of Large, Welded, Low-Pressure Storage Tanks, establishes the proper design criteria. Section VIII of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code may provide useful design guidelines, although they are not directly applicable to tanks with operating pressures below 15 psig. 2.3 HIGH-PRESSURE TANKS In general terms, a pressure vessel is a closed container of limited length which is subject to pressures above one or two pounds per square inch. For purposes of this discussion, a high-pressure tank or vessel is one with an operating pressure greater than 15 psig. The most comprehensive standards for the design, fabrication, and inspection of high-pressure tanks is found in the ASME Boiler and Pressure Vessel Code. This is an 11-section publication that is issued every three years. Most states have passed regulations which make all or certain parts of the ASME Code legal requirements, and have inspectors to enforce provisions of the Code. Sections of the ASME Code applicable to the design and inspection of high-pressure storage tanks are: Section II - Material Specifications; Section V - Nondestructive Examination; Section VIII - Pressure Vessels, Division 1; Pressure Vessels, Division 2 - Alternative Rules; Section IX - Welding Qualifications; and Section X - Fiberglass-Reinforced Plastic Pressure Vessels. 2-6 ------- Other codes pertinent to high-pressure storage systems have been developed by the American Petroleum Institute and the National Fire Protection Association. These include: API 510 - Pressure Vessel Inspection Code; ft?I " Guide for the Inspection of Refinery Equipment, Chapter VI, Pressure Vessels; § API Standard 2510 - Design and Construction of LP Gas Instal- 1ations at Marine and Pipeline Terminals, Natural Gas Proc- essing Plants, Refineries, and Tank Farms; NFPA 58 - Liquefied Petroleum Gases, Storage and Handling; t NFPA 59A - Liquefied Natural Gas, Storage and Handling; and NFPA 43C - Oxidizing Materials, Gaseous, Storage. 2.4 STORAGE TANK CONSTRUCTION MATERIALS Selection of the appropriate tank materials is a critical ele- ment in the design of a hazardous materials storage system. Although literally thousands of codes exist for all types of construction mate- rials, the scope of those standards and specifications does not neces- sarily address their application to hazardous materials storage. Therefore, the designer is advised to consult the codes, such as those identified in Sections 2.1 through 2.3, most applicable to the type of storage under consideration. The codes will generally identify, or give references to, pertinent materials standards. As an example, the base materials specifications in Parts A and B of the ASME Boiler and Pressure Vessel Code, Section II, are similar or identical to those of the American Society for Testing and Materials (ASTM). The design engineer may then refer to the cited ASTM standard for further details. ASTM currently lists over 6,700 standards in its 66-volume, 16- section 1983 Annual Book of ASTM Standards (prior to 1983, the ASTM standards were published in 48 parts). Those sections containing material and procedural standards applicable to hazardous materials storage system design are: t Secti on 1 - Iron and Steel Products; Sect- on 2 - Nonferrous Metal Products; t Sect- on 3 - Metal Test Methods and Analytical Procedures; Sect on 6 - Paints, Related Coatings, and Aromatics; Sect- on 8 - Plastics; Sect on 9 - Rubber; Section 11 - Water and Environmental Technology; 2-7 ------- Section 14 - General Methods and Instrumentation; and Section 15 - General Products, Chemical Specialties, and End Use Products. A complete listing of ASTM standards and a cross reference be- tween 1983 volumes and previous year part numbers may be obtained from: American Society for Testing and Materials 1916 Race Street Philadelphia, PA 19103 (215) 299-5462 Another source of design specifications frequently cited or incor- porated in techincal codes is the American National Standards Insti- tute (ANSI). This organization coordinates America's voluntary stan- dards system, maintaining an inventory of over 11,000 American stan- dards. ANSI also maintains the 6,000 standards promulgated by the International Organization for Standardization (ISO) and the Inter- 4 national Electrotechnical Commission (IEC). Standards of the 71 national standardizing bodies of other countries cooperating within the ISO are stocked or obtainable by ANSI. Listings of available standards may be obtained from: American National Standards Institute, Inc. 1430 Broadway New York, New York 10018 (212) 354-3300 Further information about materials standards and specifications may be obtained from a variety of industry-specific organizations. These include: American Petroleum Institute 2101 L Street, NW Washington, DC 20037 (202) 457-7160 American Society of Mechanical Engineers 345 E. 47th Street New York, NY 10017 (212) 705-7722 American Iron and Steel Institute 1000 16th Street, NW Washington, DC 20036 (202) 452-7100 Steel Structures Painting Council 4400 5th Avenue Pittsburgh, PA 15213 (412) 578-3327 2-8 ------- National Association of Corrosion Engineers 1440 South Creek Houston, TX 77084 (713) 492-0535 American Welding Society 2501 NW Seventh Street Miami, FL 33125 (305) 642-7090 American Institute of Chemical Engineers 345 E. 45th Street New York, NY 10017 (212) 705-7338 Steel Tank Institute 666 Dundee Road, Suite 705 Northbrook, IL 60062 (312) 498-1980 Society of the Plastics Industry 355 Lexington Avenue New York, NY 10017 (212) 573-9400 Chemical Manufacturers Association 2501 M Street, NW Washington, DC 20037 (202) 887-1100 National Fire Protection Association Batterymarch Park Quincy, MA 02269 (617) 328-9230 Underwriters Laboratory, Inc. 333 Pfingston Road Northbrook, IL 60062 (312) 272-8800 American Society for Metals Metals Park, OH 44073 (216) 338-5151 It should be noted that materials specifications typically address general issues such as metal strength and ductility. Material selection data for more specific considerations, such as chemical com- patibility, should be determined on a case-by-case basis according to the best professional judgement. 2-9 ------- SECTION 3 USE AND INTERPRETATION OF TECHNICAL CODES As previously indicated, technical codes are developed to delin- eate acceptable and desirable practices an industry should follow to attain uniform quality and safety in its products and operations. The codes are generally intended for use by design engineers and techni- cally qualified inspectors, and consequently are often written in highly technical language. To most laymen, the sheer number of tech- nical codes and their voluminous technical detail can make it imprac- tical to gain a thorough understanding of the codes. However some guidance can be provided to simplify use of the codes. The first step in code usage is to select the code or codes, such as those identified in Sections 2.1 to 2.4, most applicable to the subject under consideration. These codes are usually identified in their titles as "standards," "specifications," "recommended prac- tices," or by other similar descriptives. It is necessary to under- stand the distinction between these terms, as discussed in Section 1, to understand the context of the various codes. Upon identification of the codes to be studied, it is essential that the user thoroughly read the foreword, preface, and any other introductory remarks about the code. These sections usually provide valuable information about the basis and derivation of the codes, their purpose and intent, limits of application, disclaimers, dates of revision, etc., and clearly define the context within which the code should be interpreted. The next step is to review the table of contents. Besides iden- tifying the subject matters within the code, this will familiarize the reader with the format, nomenclature, and content subdivisions. This will be of aid later for cross-referencing between subsections. Note the presence and contents of any appendices. Often the appendices contain additional standards or recommendations which would not other- wise be identified in a catalog of technical code titles, and they may also include definitions or other information which would be benefi- cial to read before reading the actual technical standards. At this point, the reader should be able to identify the section and subsections of the code dealing with subjects of interest. How- ever, it is still important to read the introductory paragraphs of the individual sections to determine the scope and limitations of those sections. A consistent format is used throughout most codes to designate each of the sections, subsections, or paragraphs within the code. These designations may be in the form of letters, numbers, or a com- bination of both, arranged in sequential order. Each subsection is identified by the section designator, followed by a hyphen or period and a number in sequence (e.g., A-l, A-2; 2.1, 2.2, 2.3, etc.). This 3-1 ------- facilitates reference to particular paragraphs or subsections without the need for extensive page references. Once the proper code has been identified, and all applicable introductory and background information has been read, use of the code is simply a matter of reading the standards, referring to the proper cross references, and correctly interpreting what is written. The use of four technical codes which provide the most informa- tion in the design, fabrication, and inspection of hazardous materials storage tanks are described in the following sections. 3.1 API STANDARDS AND SPECIFICATIONS The American Petroleum Institute (API) has published hundreds of documents relevant to the production and refining of oil and petroleum products. Although originally developed for the petroleum industry, these standards can be applicable to most hazardous materials storage issues, provided that such'specific issues as chemical compatibility are properly addressed and incorporated by the designer. API codes are usually referred to as either "standards" or "specifications." According to API interpretations, these terms generally are identical in meaning. The use of one term or the other depends on the API division which developed the code. The API Produc- tion Department's codes are referred to as "specifications," and are generally applicable to atmospheric storage tanks for production fluids. "Standards" are promulgated by the API Refining Department, and are applicable to low- and high-pressure tanks. Both API standards and specifications are designated by number, with subsection indicated sequentially by decimal places. Cross- references to standards within the same code document are designated by the paragraph or subsection number only. References to other API codes are made by title and number of the other reference. Material specifications are usually handled by referencing (by number and title) the appropriate ASTM or ANSI standards, unless API data is incorporated directly into the code. In addition to its standards and specifications, API also pub- lishes various recommended practices, bulletins, and publications. These documents do not set forth specific criteria or minimum stan- dards that tank designs must meet before receiving API approval. How- ever, they are useful as sources of further information about prob- lems, hazards, or other practices related to the standards and specif- ications. 3.2 NATIONAL FIRE CODES The National Fire Codes are an annual, 16-volume publication of the National Fire Protection Association (NFPA). These volumes are compilations of various individual codes, standards, recommended prac- tices, manuals, guides, and model laws prepared by the NFPA. Only those documents which have been adopted by NFPA are included in the National Fire Codes. Volumes 1 through 12 of the National Fire Codes contain NFPA codes and standards judged suitable for legal adoption and enforcement by government agencies. Volumes 13 through 16 contain recommended practices, manuals, and guides identifying good engineering practices. These volumes also include model laws and enabling acts which may be of help to regulatory bodies. Many of the NFPA documents have been approved as standards by ANSI. 3-2 ------- Most of the documents in the National Fire Codes are available as separate pamphlets. A complete listing of these is found in the inside front and back covers of each volume of the National Fire Codes. This listing identifies the document's NFPA Code Number and the National Fire Codes volume number in which the listed title of interest may be found. This listing is suggested as the starting point for locating applicable NFPA standards. Use of the NFPA codes is similar to the use of API codes. Each code is divided into chapters covering different elements of the code. The chapters are then divided into subsections indicated by the chap- ter number, a hyphen, and sequential subsection numbers. Paragraphs within each subsection are further indicated by sequential decimal places following the subsection number. For example, NFPA 30, Flam- mable and Combustible Liquids Code, contains: CHAPTER 2 TANK STORAGE 2-1 Design and Construction of Tanks 2-1.1 Materials 2-1.2 Fabrication 2-1.2.1 (Paragraph 1) 2-1.2.2 (Paragraph 2) Pages within the code are indicated by sequential page numbers pre- ceded by the code number (e.g., page 30-17). References to other por- tions of the same code are indicated by only the section, subsection, or paragraph numbers. References to other codes refer to the title and number of the other code. 3.3 ASTM STANDARDS The 1983 Annual Book of ASTM Standards contains over 6,700 cur- rent standards, divided into 16 sections of related subject areas. These sections are published in 66 volumes which further subdivide standards for related items. (Prior to 1983, the ASTM Standards were published in 48 parts.) Location of applicable ASTM standards is facilitated by use of the index, Section 00 (Part 48 in pre-1983 edi- tions). The index provides a listing of ASTM Standards by subject and by ASTM's alphanumeric code listing. The main subject entries refer to subjects taken directly from the scope of the standard, or they may highlight similar standards. In either case, the subject listing will be followed by the standard number in parentheses, and the number of the section where it may be found. Cross references within the index guide the user from related terms to the listed subject entries. These cross references are designated as "See" or "See Also" (or Sa) written in italics. Each adopted or tentative ASTM standard has an individual serial designation listed in the alphanumeric index. This consists of a capital letter, a serial number of one to four digits, a hyphen, and a two-digit number indicating the year of adoption or latest revision. The letter at the beginning of the serial number indicates the general classification of the standard: A = Ferrous Metals, B = Nonferrous Metals; 3-3 ------- C = Cementitious, Ceramic, Concrete, and Masonry Materials; D = Miscellaneous Material; E = Miscellaneous Subjects; F = Materials for Specific Applications; G = Corrosion, Deterioration, and Degradation of Materials; and ES = Emergency Standards. The serial number may be followed by a lower case letter which denotes a revision occurring in the same year as the year of adoption or latest revision. A capital letter "T" at the end of the standard is used to denote a tentative standard. The letter "M" after the serial number designates a standard in metric units. The standard number may be followed by a number in parentheses, which indicates the year the standard was last reapproved. As an example, A236-69a (1974) refers to a specification for carbon steel forgings for railway use, first adopted in 1969,' indicated by the "69" after the hyphen; then revised in 1969, indicated by the letter "a"; and reapproved in 1974, indicated by that date in parentheses. The title is given following the standard's serial designation. A boldface number following the title indicates the volume in which the standard may be found. The ASTM standards are cited frequently as design criteria by such organizations as API or ASME. When cited, the complete designation of standard number and title is usally given. The alpha- numeric index may be used to locate the specific reference. 3.4 ASME BOILER AND PRESSURE VESSEL CODE The American Society of Mechanical Engineers wrote the ASME Boiler and Pressure Vessel Code to provide rules for the design, fabrication, and inspection of boilers and pressure vessels. The ASME Code is written by a large Boiler and Pressure Vessel Committee and several subcommittees composed of engineers appointed by ASME. The Code Committee meets regularly to review the Code and to consider requests for its interpretation or revision. Interpretations and special provisions adopted by the committee are published in "Mechani- cal Engineering," and in a supplement to the ASME Code entitled "Code Cases." By itself, the ASME Code has no legal status. However, most states have adopted at least parts of the Code as their legal require- ments, and employ inspectors to enforce provisions of the Code. A new edition of the ASME Code is issued every three years, with the latest edition scheduled for 1983. Addenda to the Code are published semi- annually between editions. Although ASME considers any edition of the Code to be adequate, certain issues of the Code may be specified as legal requirements by some regulatory bodies. The chief inspectors of all states and municipalities which have adopted the code form the National Board of Boiler and Pressure Vessel Inspectors. The Board promotes uniform enforcement of Code rules by examining and commissioning inspectors. Qualified inspectors employed by a state, municipality, or insurance company may inspect a pressure vessel and permit it to be stamped "ASME-N.B." (The "N.B." stands for "National Board"). A vessel bearing the "N.B." stamp and registered with the National Board generally may be used and sold in any state. Inspectors employed by a vessel user may only use the ASME stamp, which somewhat limits the use of those vessels. 3-4 ------- As indicated in Section 2.3, the ASME Code is published in 11 Sections. The user of the code should begin with the section title deemed most likely to cover the subject of interest. For storage applications, "Section VIII, Pressure Vessels, Division 1," and "Pres- sure Vessels, Division 2, Alternative Rules" would be the most likely starting point. Division 1 is the Pressure Vessel Code as it has existed in the past. Division 2 was developed as a means of per- mitting higher design stresses while ensuring at least as great a degree of safety as Division 1. Section VIII, Division 1 is divided into three subsections: A, General Requirements; B, Fabrication Methods; and C, Materials of Con- struction. These subsections are further divided into a total of 13 Parts, which are designated by two letters, the first of which is "U" for "unfired." These are followed by two groups of appendices. The mandatory appendices, indicated by Roman numerals, detail procedures frequently referred to in the ASME Code. The non-mandatory appen- dices, designated by capital letters, provide information and sug- gested procedures which are not essential, but may be helpful to Code users. Of particular help to someone new to the Code are Appendices III and L. Appendix III defines many of the terms used in the Code, and is a good starting point for a first-time user. Appendix L pro- vides sample problems illustrating application of Code formulas and rules, and is useful to the novice designer. Section VIII, Division 2 is more sophisticated than Division 1, and requires a more technically competent engineer to use it. Divi- sion 1 employs a safety factor of about 4 in its standards, but ignores many secondary stresses which act in the vessel. Division 2 allows higher stresses, but requires thorough stress analysis and closer quality control of materials and fabrication. Because of the extensive nature of the ASME Code, the user is advised to pay particular attention to background information, tables of contents, and indices (found at the end of each section) before using the Code. Although the style of designating parts, subsections, or articles may vary from section to section, each designation is unique, and cross-referencing within a section is accomplished rather easily. References to other sections of the Code will include the title and section number. 3-5 ------- SECTION 4 CONCLUSIONS AND RECOMMENDATIONS As discussed in Section 3, technical codes are quite complex, and often difficult to understand. They provide a tremendous amount of technical detail which may easily overwhelm the user if the codes are not approached systematically. This requires selection of the appro- priate code with which to begin the search for information. As illustrated by Table 2-1, there are many technical codes applicable to specific aspects of hazardous materials storage systems. Selection of the inappropriate code may result in failure to determine standards specifically applicable to the problem at hand, and it may lead to an unnecessarily laborious search for the correct information. Therefore, selection of the code which appears to offer the broadest coverage of the subject of interest will either provide the informa- tion sought or direct the user to other pertinent sources. It is important to consult those codes promulgated by organiza- tions most involved with the type of materials to be used. For exam- ple, Section 2.1 identified standards of the American Petroleum Insti- tute and the American Water Works Association (AWWA) which are appli- cable to atmospheric storage tanks. Because of API's extensive expe- rience with the petroleum and petrochemical industry, its codes could be expected to provide more information relevant to hazardous mate- rials storage, whereas the AWWA standards would have much more limited application. Therefore, because of their relevance and broad scope, it is recommended that the designer searching for standards applicable to specific types of storage tanks begin the search with the following codes: API Specification 12D and API Standards 650 for atmospheric tanks; API Standard 620 for low-pressure tanks; and « ASME Boiler and Pressure Vessel Code, Section VIII for high- pressure tanks. These codes will in turn cross reference the appropriate codes for materials, appurtenances, etc. Although it may seem obvious, elementary, and therefore, unneces- sary, the foreword, table of contents, and introductory paragraphs must be read if the codes are to be properly understood. To the cas- ual user reading the code for informational purposes, the introductory paragraphs describe the framework within which the code is applicable. To the designer, the introductory material may identify the scope and application of the code and other sources of valuable information. 4-1 ------- Because codes are revised regularly, it is also important that the user consult the latest applicable edition. Technical codes are written by and for technical experts within a particular field. Therefore, the technical language may be unfamiliar to some users. Interpretation of the code, and formulation of judge- ments based on those interpretations, should always be left to indi- viduals technically qualified to make such interpretations. 4-2 ------- |