AWS C4 3 C4 3M-2018 Recommended Practices for Oxyfuel Gas Heating Torch Operation (Fourth Edition).pdf

1、AWS C4.3/C4.3M:2018An American National StandardRecommendedPractices forOxyfuel GasHeating TorchOperationAWS C4.3/C4.3M:2018An American National StandardApproved by theAmerican National Standards InstituteJune 6, 2017Recommended Practicesfor Oxyfuel Gas HeatingTorch Operation4th EditionSupersedes AW

2、S C4.3/C4.3M:2007Prepared by theAmerican Welding Society (AWS) C4 Committee on Oxyfuel Gas Welding and CuttingUnder the Direction of theAWS Technical Activities CommitteeApproved by theAWS Board of DirectorsAbstractThe newly revised manual for oxyfuel gas heating torch operation includes the latest

3、procedures to be used in conjunc-tion with oxyfuel gas heating equipment. The manual also includes the latest safety requirements. Complete lists ofequipment are available from individual manufacturers.iiAWS C4.3/C4.3M:2018ISBN: 978-0-87171-915-7 2017 by American Welding SocietyAll rights reservedPr

4、inted in the United States of AmericaPhotocopy Rights. No portion of this standard may be reproduced, stored in a retrieval system, or transmitted in anyform, including mechanical, photocopying, recording, or otherwise, without the prior written permission of the copyrightowner.Authorization to phot

5、ocopy items for internal, personal, or educational classroom use only or the internal, personal, oreducational classroom 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

6、 01923, tel: (978) 750-8400; Internet:.iiiAWS C4.3/C4.3M:2018Statement on the Use of American Welding Society StandardsAll standards (codes, specifications, recommended practices, methods, classifications, and guides) of the AmericanWelding Society (AWS) are voluntary consensus standards that have b

7、een developed in accordance with the rules of theAmerican National Standards Institute (ANSI). When AWS American National Standards are either incorporated in, ormade part of, documents that are included in federal or state laws and regulations, or the regulations of other governmentalbodies, their

8、provisions carry the full legal authority of the statute. In such cases, any changes in those AWS standardsmust be approved by the governmental body having statutory jurisdiction before they can become a part of those lawsand regulations. In all cases, these standards carry the full legal authority

9、of the contract or other document that invokesthe AWS standards. Where this contractual relationship exists, changes in or deviations from requirements of an AWSstandard must be by agreement between the contracting parties.AWS American National Standards are developed through a consensus standards d

10、evelopment process that bringstogether volunteers representing varied viewpoints and interests to achieve consensus. While 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 info

11、rmation or the soundness of any judgments contained in its standards.AWS disclaims liability for any injury to persons or to property, or other damages of any nature whatsoever, whetherspecial, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, o

12、r relianceon this standard. AWS also makes no guarantee or warranty as to the accuracy or completeness of any information publishedherein.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

13、 AWS undertaking to perform any duty owed by any person or entity to someoneelse. Anyone using these documents should rely 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.

14、It isassumed that the use of this standard and its provisions is entrusted to appropriately qualified and competent personnel.This standard may be superseded by new editions. This standard may also be corrected through publication of amendmentsor errata, or supplemented by publication of addenda. In

15、formation on the latest editions of AWS standards includingamendments, errata, and addenda is posted on the AWS web page (www.aws.org). Users should ensure that they havethe latest edition, amendments, errata, and addenda.Publication of this standard does not authorize infringement of any patent or

16、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 this standard.AWS does not monitor, police, or enforce compliance with this s

17、tandard, nor does it have the power to do so.Official interpretations 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: Manag

18、ing Director, Standards Development, 8669 NW 36 St, # 130, Miami, FL 33166 (see Annex D). Withregard to technical inquiries made concerning AWS standards, oral opinions on AWS standards may be rendered. Theseopinions are offered solely as a convenience to users of this standard, and they do not cons

19、titute professional advice.Such opinions represent only the personal opinions of the particular individuals giving them. These individuals do notspeak on behalf of AWS, nor do these oral opinions constitute official or unofficial opinions or interpretations of AWS.In addition, oral opinions are info

20、rmal and should not be used as a substitute for an official interpretation.This standard is subject to revision at any time by the AWS C4 Committee on Oxyfuel Gas Welding and Cutting. It mustbe reviewed every five years, and if not revised, it must be either reaffirmed or withdrawn. Comments (recomm

21、endations,additions, or deletions) and any pertinent data that may be of use in improving this standard are required and should beaddressed to AWS Headquarters. Such comments will receive careful consideration by the AWS C4 Committee onOxyfuel Gas Welding and Cutting and the author of the comments w

22、ill be informed of the Committees response to thecomments. Guests are invited to attend all meetings of the AWS C4 Committee on Oxyfuel Gas Welding and Cuttingto express their comments verbally. Procedures for appeal of an adverse decision concerning all such comments areprovided in the Rules of Ope

23、ration of the Technical Activities Committee. A copy of these Rules can be obtained fromthe American Welding Society, 8669 NW 36 St, # 130, Miami, FL 33166.This page is intentionally blank.ivAWS C4.3/C4.3M:2018vAWS C4.3/C4.3M:2018PersonnelAWS C4 Committee on Oxyfuel Gas Welding and CuttingL. L. List

24、on, Chair ConsultantB. F. Johnson, Vice Chair Miller Electric Manufacturing CompanyA. Naumann, Secretary American Welding SocietyJ. F. Henderson Victor Technologies, IncorporatedM. J. Hogan The Harris Products Group, A Lincoln Electric CompanyR. K. Langford Victor Technologies, IncorporatedC. R. McG

25、owan McGowan Technical Services, IncorporatedD. B. Overvaag Miller Electric Manufacturing CompanyJ. C. Papritan The Ohio State UniversityA. T. Sheppard The DuRoss GroupAdvisors to the AWS C4 Committee on Oxyfuel Gas Welding and CuttingJ. D. Compton J. C. therefore, each system must be used independe

26、ntly.1.3 Safety. Safety issues and concerns are addressed in this standard although health issues and concerns are beyond thescope of this standard. Safety and health information is available from the following sources:American Welding Society:(1) ANSI Z49.1, Safety in Welding, Cutting, and Allied P

27、rocesses(2) AWS Safety and Health Fact Sheets(3) Other safety and health information on the AWS websiteMaterial or Equipment Manufacturers:(1) Safety Data Sheets supplied by materials manufacturers(2) Operating Manuals supplied by equipment manufacturersAWS C4.3/C4.3M:20182Applicable Regulatory Agen

28、ciesWork performed in accordance with this standard may involve the use of materials that have been deemed hazardous,and may involve operations or equipment that may cause injury or death. This standard does not purport to address allsafety and health risks that may be encountered. The user of this

29、standard should establish an appropriate safety programto address such risks as well as to meet applicable regulatory requirements. ANSI Z49.1 should be considered whendeveloping the safety program.2. Normative ReferencesThe documents listed below are referenced within this publication and are manda

30、tory to the extent specified herein. Forundated references, the latest edition of the referenced standard shall apply. For dated references, subsequent amend-ments to, or revisions of, any of these publications do not apply.American Welding Society (AWS) standards:1AWS A3.0M/A3.0, Standard Welding T

31、erms and Definitions, Including Terms for Adhesive Bonding, Brazing, Sol-dering, Thermal Cutting, and Thermal Spraying; andAWS F4.1, Recommended Safe Practices for Preparation for Welding and Cutting of Containers and Piping.American National Standards Institute (ANSI) standard:2ANSI Z49.1, Safety i

32、n Welding, Cutting, and Allied ProcessesCompressed Gas Association (CGA) standard:3CGA E-1, Standard for Rubber Welding Hose and Hose Connections for Gas Welding, Cutting, and Allied Processes.International Organization for Standardization (ISO) standard:4ISO 3821, Gas welding equipment Rubber hoses

33、 for welding, cutting, and allied processesNational Fire Protection Association (NFPA) standard:5NFPA-51:2013, Standard for the Design and Installation of Oxygen-Fuel Gas Systems for Welding, Cutting, andAllied Processes.Occupational Safety and Health Administration (OSHA) document:6OSHA 29CFR1910,

34、Occupational Safety and Health StandardsRubber Manufacturers Association (RMA) standard:7RMA IP-7, Specifications for Rubber Welding Hose, Washington, DC: Rubber Manufacturers Association.1AWS standards are published by the American Welding Society, 8669 NW 36 St, # 130, Miami, FL 33166.2This ANSI s

35、tandard is published by the American Welding Society, 8669 NW 36 St, # 130, Miami, FL 33166.3CGA standards are published by the Compressed Gas Association, 14501 George Carter Way, Suite 103, Chantilly, VA 20151.4ISO standards are published by the International Organization for Standardization, Chem

36、in de Blandonnet 8 CP 401, 1214 Vernier,Geneva, Switzerland.5NFPA standards are published by the National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02169.6OSHA standards are published by the Occupational Safety and Health Administration, U.S. Government Printing Office, Washington

37、,DC 20402.7RMA standards are published by the Rubber Manufacturers Association, 1400 K Street, NW, Suite 900, Washington, DC 20005.AWS C4.3/C4.3M:201833. Terms and DefinitionsThe terms listed are used in various sections of this document and require definition for correct interpretation. Most ofthes

38、e terms are not contained in AWS A3.0M/A3.0, Standard Welding Terms and Definitions, or if they are listed inAWS A3.0, their definitions have been enhanced to clarify their use in this document.These terms describe potentially hazardous events that can occur when using oxyfuel gas equipment. Operato

39、rs and theiremployers should understand these events and the terms that are associated with them. See 6.2.For the purposes of this document, the following definitions apply:backfire. The momentary recession of the flame into the torch, potentially causing a flashback or sustained backfire. Itis usua

40、lly signaled by a popping sound, after which the flame may either extinguish or reignite at the end of the tip.See also flashback and sustained backfire.flashback. The recession of the flame through the torch and into the hose, regulator, and/or cylinder, potentially causingan explosion. See also ba

41、ckfire and sustained backfire.sustained backfire. The recession of the flame into the torch body with continued burning characterized by an initialpopping sound followed by a squealing or hissing sound, potentially burning through inside the torch body. See alsobackfire and flashback.4. Equipment an

42、d SuppliesTo perform oxyfuel heating operations, some or all of the following are needed:8OxygenFuel gasCylinder or line pressure regulatorsCheck valves or flashback arrestors (see Clause 8 for additional selection information).Oxyfuel hosesHeating or welding torchesTorch extensions (straight or cur

43、ved)Heating tips or heating headsSpark lightersTip cleanersSafety equipment and personal protective equipment (PPE)Temperature indicating devicesCheck valves or flashback arrestors may be used. However, before using these devices, the user should determine thatthey will allow adequate flow for the e

44、quipment being used. These devices restrict flow which could result in a backfireor sustained backfire. See Clause 8 for more information on these devices.4.1 Oxygen Supply. Oxygen of high purity (99.5% minimum) is supplied in individual cylinders of various sizes (seeFigure 1) or may be distributed

45、 by pipeline from manifold cylinders or bulk liquid tanks. Oxygen should always becalled by its proper name, “OXYGEN,” and should not be referred to as “AIR.” Regardless of the source, sufficientpressure and flow capabilities should be available for the work to be done. Consult manufacturers literat

46、ure for pressureand volume requirements.8To meet Federal OSHA requirements, all gas apparatus must be listed in or comply with CFR 1910, subparagraph 253.AWS C4.3/C4.3M:201844.1.1 Liquid Oxygen. Use of portable liquid oxygen cylinders is often advantageous. It should be noted that thesecylinders, wi

47、thout additional external vaporizers, are limited to continuous withdrawal rates of 250 cu ft/h to 300 cu ft/h117 L/min to 142 L/min. If requirements exceed these withdrawal limitations, these cylinders are not recommended.Oxygen vigorously accelerates combustion. Improper use can result in fire or

48、explosion. Oxygen shall not be used inpneumatic tools, to clean equipment, dust off clothing, provide ventilation, or any other application not intended for pureoxygen. Oil, grease, and dust are highly combustible when mixed with pure oxygen. Equipment damage or a serious per-sonal injury can result

49、 from improper use of oxygen.4.2 Fuel Supply. Many different fuel gases are utilized in the oxyfuel gas heating process (see Annex C). They includeacetylene, propane, natural gas/methane, propylene, hydrogen, and several propane-based mixtures. The different fuelgases vary in flame characteristics. The oxyfuel operator should become familiar with the proper flame adjustments forthe fuel gas being used. The gas supplier should be contacted for the proper fuel-gas parameters.Fuel gases are supplied in individual cylinders (see Figure 2) or distributed by pipeline from ma