1、Preparing Tank Bottoms for Hot WorkAPI RECOMMENDED PRACTICE 2207 SEVENTH EDITION, JUNE 2017Special NotesAPI publications necessarily address problems of a general nature. With respect to particular circumstances, local, state, and federal laws and regulations should be reviewed.Neither API nor any o
2、f APIs employees, subcontractors, consultants, committees, or other assignees make any warranty or representation, either express or implied, with respect to the accuracy, completeness, or usefulness of the information contained herein, or assume any liability or responsibility for any use, or the r
3、esults of such use, of any information or process disclosed in this publication. Neither API nor any of APIs employees, subcontractors, consultants, or other assignees represent that use of this publication would not infringe upon privately owned rights.API publications may be used by anyone desirin
4、g to do so. Every effort has been made by the Institute to assure the accuracy and reliability of the data contained in them; however, the Institute makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for
5、loss or damage resulting from its use or for the violation of any authorities having jurisdiction with which this publication may conflict.API publications are published to facilitate the broad availability of proven, sound engineering and operating practices. These publications are not intended to
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13、cycle. Status of the publication can be ascertained from the API Standards Department, telephone (202) 682-8000. A catalog of API publications and materials is published annually by API, 1220 L Street, NW, Washington, DC 20005.Suggested revisions are invited and should be submitted to the Standards
14、Department, API, 1220 L Street, NW, Washington, DC 20005, standardsapi.org.iiiContentsPage1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Normative References . . . . . . .
15、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Terms, Definitions, Acronyms, and Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.1 Terms and Definitions. . . . . .
16、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33.2 Acronyms and Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 Precautions .
17、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.1 General Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18、 . . . . . . . . 84.2 Specific Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Inspection Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19、. . . . . . . . . . . . . . . . . . . . . 115.1 General Inspection Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115.2 Specific Inspection Procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20、. . . . . . . . . . . . . . . . . . . . . . . . . . . 116 Work Procedures and Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126.2 Minor Repairs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126.3 Major Repairs. . . . . . . . . . . . . . . . . . . .
22、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126.4 Perimeter Repairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136.5 Double-bottom Ins
23、tallation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136.6 Sectional Repairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24、 . 147 Summary of Significant Safety Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25、. . . . . . . . . . 18vIntroductionThe 7th edition of API Recommended Practice 2207, Preparing Tank Bottoms for Hot Work, is significantly updated from prior editions. A new Section 7, “Summary of Significant Safety Considerations,” provides a quick review and can be used to guide users to content i
26、n the body of this recommended practice.Two API Individual Certification Programs (ICPs) are referenced in this recommended practice. The API 653 Aboveground Storage Tanks Inspector Certification Program evaluates individual personnel qualifications to inspect and determine conformance with API Stan
27、dard 653, Tank Inspection, Repair, Alteration, and Reconstruction. Because tank entry is often an integral part of the process, the API Tank Entry Supervisor Individual Certification Program provides a tool for certifying supervisors who will evaluate hazards to minimize any risks associated with ta
28、nk entry. API 2207 primarily discusses work practices that have been used safely and is not a regulatory compliance document. However, it does update the listing of potentially relevant regulations. Federal, state, and local regulations or laws may contain additional requirements that must be taken
29、into account when a tank repair program is developed for a specific facility. Since the essential elements of this publication are based on current industry safe operating practices and existing consensus standards, these listings have also been updated and expanded. References made to “OSHA” refer
30、to U.S. Federal regulations. Comparable or more restrictive requirements may exist in other jurisdictions (states or countries), and the appropriate requirements should be used. Where no regulations or other legal requirements exist, the OSHA standards provide a useful reference and are readily avai
31、lable for download from the Internet at www.osha.gov.This recommended practice provides information to assist safe performance of hot work on the bottoms of storage tanks that have been in service to store flammable products. This work activity has specific precautions and work practices. The unders
32、tanding of potential hazards, relevant precautions, and techniques, and application of this knowledge, can help improve safety performance and reduce the probability of incidents.Tanks that previously have contained flammable or combustible liquids, regardless of their age and type of construction,
33、must be considered unsafe for hot work until inspected and approved by a qualified person. These inspections include visual examination and atmospheric testing to evaluate physical and atmospheric hazards (flammability, oxygen deficiency, and potentially toxic contaminants). Emphasis is on special t
34、echniques required in the performance of hot work to prevent the ignition of flammable gases or vapors that may be trapped under the tank bottom.Each repair of tank bottoms must receive careful consideration and individual evaluation. The safety procedures described in this recommended practice prov
35、ide various methods that have been used successfully for preparing tank bottoms for hot work. These procedures will apply to most situations; however, each job must be independently evaluated to ensure safe work.vii1 Preparing Tank Bottoms for Hot Work 1 Scope This recommended practice addresses onl
36、y the safety aspects of hot work performed on petroleum 1.1storage tank bottoms. It discusses safety precautions for preventing fires, explosions, and associated injuries. The term “hot work,” as used in this publication, is defined as an operation that can produce a spark or flame hot enough to ign
37、ite flammable vapors. API 2009 provides more in-depth information on safe hot work practices, and its requirements are not duplicated here. This recommended practice does not contain all safety precautions and procedures that may be 1.2required prior to, during, or after a specific hot work activity
38、. All hot work should be performed in compliance with applicable federal, state, and local regulatory requirements and recognized industry practices. Work practices of concern for working on tank bottoms include, but are not limited to, confined space entry, lockout/tagout, atmospheric testing, vent
39、ilation, and requirements for use of personal protective equipment (PPE). API 2015 provides guidance for tank entry consistent with OSHA regulations noted in Section 2, Normative References. This recommended practice does not repeat the detailed information provided in the referenced documents. Some
40、 of the relevant OSHA regulations from 29 CFR Part 1910 and 29 CFR Part 1926 are included in the references. It is the responsibility of each organization to review and comply with applicable regulatory requirements. This recommended practice does not cover: 1.3 guidance for compliance with safety o
41、r environmental regulations or codes; engineering specifications for tank construction or rebuilding (see API tank standards); specific guidance for repair of shop-fabricated tanks, which is addressed by STI/SPFA SP031. These tanks include those built to UL 142, API 650 Appendix J, STI/SPFA abovegro
42、und tank standards, as well as others; specific guidance for tank entry (see API 2015); welding techniques, craft skills or qualification of welders (see referenced welding standards); normal “safe work” practices such as fall protection, PPE, slip/trip/fall, etc.; entry or work in inert environment
43、s (see API 2217A); entry into confined spaces for construction activities (see OSHA 29 CFR Part 1926, Subpart AA, and Part 1926.1200). Concepts of Hazard and Risk 1.4Hazards are properties of materials (or situations) with the inherent ability to cause harm. Flammability, 1.4.1toxicity, corrosivity,
44、 and stored chemical or mechanical energy all are hazards associated with various industrial materials or situations. Risk requires exposure. A fire or hot surface can cause thermal skin burns or a corrosive acid can cause chemical skin burns, but these can occur only if there is contact exposure to
45、 skin. In an empty tank, a floating roof represents a “stored mechanical energy” hazard that might fall on persons working underneath, and so must be properly secured to reduce the risk of contact before performing entry work. There is no risk when there is no potential for exposure. 1.4.2Determinin
46、g the level of risk involves understanding hazards and estimating the probability of 1.4.3exposure and severity of consequences that could lead to harm. While the preceding examples relate hazards to the risk to people, the same principles are valid for evaluating property risk. For instance, a flam
47、mable 2 API RECOMMENDED PRACTICE 2207 mixture of hydrocarbon vapors in air can ignite if exposed to a source of ignition, resulting in a fire that could damage property, as well as injure people. Relationship to Regulations 1.5This recommended practice aims to share practices, which over time have b
48、een useful in injury prevention programs. The specifics of compliance with either safety or environmental laws or regulations are outside the scope of this recommended practice, but should be carefully reviewed by those authorizing and conducting work. 2 Normative References The following referenced
49、 documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. NOTE There is a Bibliography at the end of this recommended practice that lists additional relevant documents not specifically cited in the body of this document. API Standard 653, Tank Inspection, Repair, Alteration, and Reconstruction API Recommended Practice 2009, Safe Welding, Cutting and Hot Work Practices in the Petroleum and Petrochemical Indus
