1、Safe Practicesfor the Preparationof Containers andPiping forWeldingand CuttingAWS F4.1:2007An American National Standard550 N.W. LeJeune Road, Miami, FL 33126AWS F4.1:2007An American National StandardApproved by theAmerican National Standards InstituteAugust 24, 2007Safe Practicesfor the Preparation
2、 ofContainers and Piping forWelding and Cutting5th EditionSupersedes AWS F4.1:1999Prepared by theAmerican Welding Society (AWS) Committee on Labeling and Safe PracticesUnder the Direction of theAWS Committee on Safety and HealthApproved by theAWS Board of DirectorsAbstractThis standard informs the r
3、eader of the necessary safe practices to be followed in the cleaning and preparation ofcontainers and piping for welding or cutting. It describes various methods for cleaning, including water, steam, hotchemical, and mechanical, and techniques to be used for their proper preparation, such as inertin
4、g.iiAWS F4.1:2007International Standard Book Number: 978-0-87171-078-9American Welding Society550 N.W. LeJeune Road, Miami, FL 33126 2007 by American Welding SocietyAll rights reservedPrinted in the United States of AmericaPhotocopy Rights. No portion of this standard may be reproduced, stored in a
5、retrieval system, or transmitted in anyform, including mechanical, photocopying, recording, or otherwise, without the prior written permission of the copyrightowner.Authorization to photocopy items for internal, personal, or educational classroom use only or the internal, personal, oreducational cla
6、ssroom use only of specific clients is granted by the American Welding Society provided that the appropriatefee is paid to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, tel: (978) 750-8400; Internet:.iiiAWS F4.1:2007Statement on the Use of American Welding Society StandardsA
7、ll standards (codes, specifications, recommended practices, methods, classifications, and guides) of the AmericanWelding Society (AWS) are voluntary consensus standards that have been developed in accordance with the rules of theAmerican National Standards Institute (ANSI). When AWS American Nationa
8、l Standards are either incorporated in, ormade part of, documents that are included in federal or state laws and regulations, or the regulations of other govern-mental bodies, their provisions carry the full legal authority of the statute. In such cases, any changes in those AWSstandards must be app
9、roved by the governmental body having statutory jurisdiction before they can become a part ofthose laws and regulations. In all cases, these standards carry the full legal authority of the contract or other documentthat invokes the AWS standards. Where this contractual relationship exists, changes i
10、n or deviations from requirementsof an AWS standard must be by agreement between the contracting parties.AWS American National Standards are developed through a consensus standards development process that bringstogether volunteers representing varied viewpoints and interests to achieve consensus. W
11、hile AWS administers the processand establishes rules to promote fairness in the development of consensus, it does not independently test, evaluate, orverify the accuracy of any information or the soundness of any judgments contained in its standards.AWS disclaims liability for any injury to persons
12、 or to property, or other damages of any nature whatsoever, whetherspecial, indirect, consequential or compensatory, directly or indirectly resulting from the publication, use of, or relianceon this standard. AWS also makes no guaranty or warranty as to the accuracy or completeness of any informatio
13、npublished herein.In issuing and making this standard available, AWS is neither undertaking to render professional or other services for oron behalf of any person or entity, nor is AWS undertaking to perform any duty owed by any person or entity to someoneelse. Anyone using these documents should re
14、ly on his or her own independent judgment or, as appropriate, seek theadvice of a competent professional in determining the exercise of reasonable care in any given circumstances.This standard may be superseded by the issuance of new editions. Users should ensure that they have the latest edition.Pu
15、blication of this standard does not authorize infringement of any patent or trade name. Users of this standard acceptany and all liabilities for infringement of any patent or trade name items. AWS disclaims liability for the infringement ofany patent or product trade name resulting from the use of t
16、his standard.Finally, AWS does not monitor, police, or enforce compliance with this standard, nor does it have the power to do so.On occasion, text, tables, or figures are printed incorrectly, constituting errata. Such errata, when discovered, are postedon the AWS web page (www.aws.org).Official int
17、erpretations of any of the technical requirements of this standard may only be obtained by sending a request,in writing, to the appropriate technical committee. Such requests should be addressed to the American Welding Society,Attention: Managing Director, Technical Services Division, 550 N.W. LeJeu
18、ne Road, Miami, FL 33126 (see Annex B).With regard to technical inquiries made concerning AWS standards, oral opinions on AWS standards may be rendered.These opinions are offered solely as a convenience to users of this standard, and they do not constitute professionaladvice. Such opinions represent
19、 only the personal opinions of the particular individuals giving them. These individualsdo not speak on behalf of AWS, nor do these oral opinions constitute official or unofficial opinions or interpretations ofAWS. In addition, oral opinions are informal and should not be used as a substitute for an
20、 official interpretation.This standard is subject to revision at any time by the AWS Safety and Health Committee. It must be reviewed every fiveyears, and if not revised, it must be either reaffirmed or withdrawn. Comments (recommendations, additions, or deletions)and any pertinent data that may be
21、of use in improving this standard are required and should be addressed to AWSHeadquarters. Such comments will receive careful consideration by the AWS Safety and Health Committee and theauthor of the comments will be informed of the Committees response to the comments. Guests are invited to attend a
22、llmeetings of the AWS Safety and Health Committee to express their comments verbally. Procedures for appeal ofan adverse decision concerning all such comments are provided in the Rules of Operation of the Technical ActivitiesCommittee. A copy of these Rules can be obtained from the American Welding
23、Society, 550 N.W. LeJeune Road,Miami, FL 33126.This page is intentionally blank.ivAWS F4.1:2007vAWS F4.1:2007PersonnelAWS Safety and Health CommitteeD. E. Clark, Chair Idaho National Engineering and Environmental LaboratoryJ. M. Antonini, 1st Vice Chair National Institute for Occupational Safety and
24、 HealthJ. D. Jennings, 2nd Vice Chair Miller Electric Manufacturing CompanyS. P. Hedrick, Secretary American Welding SocietyM. S. Anderson ConsultantK. Bancroft U.S. Geological SurveyS. E. Ferree ESAB Welding somesolvents may be as hazardous as the deposits they areintended to remove. If chlorinated
25、 solvents are used, allresidue shall be removed before welding or cuttingbegins.When selecting chemical solvents, consultation with themanufacturer of the material to be removed would behelpful. Chemical manufacturers may recommend asolvent to use and detail a cleaning procedure.4.6 Combination of M
26、ethods. Occasionally, combi-nations of the methods of cleaning prior to welding orcutting must be used. Care shall be exercised when com-bining some of the cleaning methods to protect personneland prevent hazardous reactions.5. Preparation for Welding and Cutting5.1 Guidelines. This clause presents
27、guidelines forensuring that the containers and work area are safe forwelding and cutting. The guidelines are intended to pro-tect personnel and equipment by ensuring that thehazards are understood and adequate precautions areproperly taken. The qualified person responsible for thework done on the co
28、ntainer shall ensure that the guide-lines are followed.5.2 Safe Practices. The following steps shall be taken toensure that the work area and container are maintainedsafe for welding:5.2.1 Area. The immediate area outside and inside thecontainer shall be cleared of all obstacles and hazardousmateria
29、ls. When repairing containers in place, care shallbe taken to prevent entry of hazardous substancesreleased from the floor or soil beneath the container.5.2.2 Equipment. Personal protection equipment andfire protection equipment shall be available, serviceable,and in position for immediate use.5.2.3
30、 Ventilation. Ventilation shall be adequate forproviding a safe work atmosphere prior to and duringwelding. It may be necessary to test for toxic or flamma-ble vapors and to verify that the oxygen content of theatmosphere in the work area is maintained within accept-able limits. Where adequate venti
31、lation is not available,an independent source of breathing air shall be provided.5.2.4 Inspection. Qualified persons shall inspect theused container to verify that the cleaning is adequate. Alltest equipment shall be suitable for the intended mea-surement. In addition to visual checks, tests (which
32、mea-sure flammability or toxicity, or both, of the atmosphere)shall be made just prior to welding to ensure that theatmosphere inside the container is safe for welding.AWS F4.1:200745.2.5 Pressure Relief. Provision shall be made to pre-vent pressure buildup in the container during welding.Exhaust ga
33、ses and other gases produced during weldingshall be discharged in a safe and environmentally accept-able manner.5.2.6 Testing. The container shall be tested for haz-ardous gases, fumes, and vapors periodically to ensurethat the container and work area are safe during welding.5.2.7 Inerting. An alter
34、nate method to provide andmaintain the container in a welding condition, free fromflammable or explosive hazards, is to fill it with an inertmedium such as water, inert gas, or sand.5.2.7.1 Water Method. When the water-filledmethod is used, the container shall be placed so that itcan be kept filled
35、to within a few inches (25 mm to75 mm) of the point where welding is to be done. Thespace above the water level shall be vented so the heatedair can escape from the container.5.2.7.2 Inert Gas Method. As an alternate to thewater-filled treatment, the container can be filled withinert gas. When this
36、method is used, the qualified indi-vidual shall be informed of the percentage of inert gasthat must be present and how to safely produce andmaintain this percentage during welding, as well as bealert for suffocation hazards.5.2.7.3 Sand Method. Sand can be used as analternate to displace the hazardo
37、us atmosphere inside acontainer. The container shall be completely filled withsand before welding.5.2.7.4 Jacketed Containers. These inertingguidelines are particularly suitable for use with metal-lined jacketed containers that might be difficult to cleanthoroughly.5.2.8 Isolation. The container sha
38、ll be isolated fromfurther entry of hazardous substance. When work is to beperformed on piping in place, valves in that line shall beclosed and locked out. The pipe shall be disconnectedand drained. The open end of the pipe sections not beingworked on shall be blanked off (see 5.2.1).AWS F4.1:20075A
39、merican Gas Association (AGA).3Purging Principlesand Practices, Catalog No. XK0775-IN1, Washing-ton, DC: American Gas Association.American National Standards Institute (ANSI). Safety inWelding, Cutting, and Allied Processes, ANSI Z49.1(current edition). Miami: American Welding Society.4American Petr
40、oleum Institute (API).5Cleaning MobileTanks in Flammable or Combustible Liquid Service,Publ. 2013, Sixth Edition. Washington: AmericanPetroleum Institute, 1991.American Petroleum Institute (API). Safe Entry andCleaning of Petroleum Storage Tanks, Std 2015. SixthEdition. Washington: American Petroleu
41、m Institute,2001.American Petroleum Institute (API). Preparing TankBottoms for Hot Work, Publ. 2207, Fifth Edition.Washington, DC: American Petroleum Institute,1998.American Petroleum Institute (API). Safe Hot TappingPractices in the Petroleum and Petrochemical Indus-tries, Publ. 2201, Fifth Edition
42、. Washington, DC:American Petroleum Institute, 2003.3AGA standards are published by the American Gas Asso-ciation, 400 N. Capitol Street N.W., Washington, DC 20001.4AWS standards are published by the American WeldingSociety, 550 N.W. LeJeune Road, Miami, FL 33126.5API standards are published by the
43、American PetroleumInstitute, 1220 L Street N.W., Washington, DC 20005.American Petroleum Institute (API). Repairing CrudeOil, Liquified Petroleum Gas and Product Pipelines,RP 2200, Third Edition. Washington, DC: AmericanPetroleum Institute, 1994.American Petroleum Institute (API). Safe Welding, Cut-
44、ting, and Other Hot Work Practices in the Petroleumand Petrochemical Industries, Publ. 2009. Washing-ton, DC: American Petroleum Institute, 2002.National Fire Protection Association (NFPA).6Standardfor the Control of Gas Hazards on Vessels, NFPANo. 306, Quincy, MA: National Fire ProtectionAssociatio
45、n.National Fire Protection Association (NFPA). Standardfor Fire Prevention During Welding, Cutting, andOther Hot Work, NFPA No. 51B, Quincy, MA:National Fire Protection Association.National Fire Protection Association (NFPA). StandardProcedures for Cleaning or Safeguarding SmallTanks and Containers
46、Without Entry, NFPA No. 327,Quincy, MA: National Fire Protection Association.CGA Publications. Publications of the Compressed GasAssociation. 1725 Jefferson Davis Highway, Arling-ton, Virginia 22202-4102.6NFPA standards are published by the National Fire ProtectionAssociation, 1 Batterymarch Park, Q
47、uincy, MA 02269.Annex ABibliographyThis annex is not part of AWS F4.1:2007, Safe Practices for the Preparation of Containersand Piping for Welding and Cutting, but is included for informational purposes only.This page is intentionally blank.AWS F4.1:20076AWS F4.1:20077B1. IntroductionThe American We
48、lding Society (AWS) Board of Directorshas adopted a policy whereby all official interpretationsof AWS standards are handled in a formal manner. Underthis policy, all interpretations are made by the committeethat is responsible for the standard. Official communica-tion concerning an interpretation is
49、 directed through theAWS staff member who works with that committee. Thepolicy requires that all requests for an interpretation besubmitted in writing. Such requests will be handled asexpeditiously as possible, but due to the complexity ofthe work and the procedures that must be followed, someinterpretations may require considerable time.B2. ProcedureAll inquiries shall be directed to:Managing DirectorTechnical Services DivisionAmerican Welding Society550 N.W. LeJeune RoadMiami, FL 33126All inquiries shall contain the name, address, and affilia-tion of the inquirer, and they shall provide en
