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

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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


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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

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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

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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

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LIST OF TABLES
Table
2-1 Major Technical Codes Applicable to Storage Systems
vi i

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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

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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

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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

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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

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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

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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

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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

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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

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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

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•	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

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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

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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

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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.
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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;
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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.
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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.
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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.
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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.
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