1、Guide for RootPass Welding ofPipe WithoutBackingAWS D10.11M/D10.11:2007An American National Standard550 N.W. LeJeune Road, Miami, FL 33126AWS D10.11M/D10.11:2007An American National StandardApproved by theAmerican National Standards InstituteOctober 13, 2006Guide forRoot Pass Welding ofPipe Without
2、Backing3rd EditionSupersedes AWS D10.11-87Prepared by theAmerican Welding Society (AWS) D10 Committee on Piping and TubingUnder the Direction of theAWS Technical Activities CommitteeApproved by theAWS Board of DirectorsAbstractThis standard presents guidelines for welding the root pass of metal pipe
3、 butt joints with an open root or a consumableinsert. Joint designs, assembly, consumable insert configurations, base metals, filler metals, and purging are discussed.Applicable arc welding processes and techniques are described.iiAWS D10.11M/D10.11:2007International Standard Book Number: 0-87171-64
4、4-5American 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 retrieval system, or transmitted in anyform, including mechanical,
5、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 classroom use only of specific clients is granted by the American Weld
6、ing Society provided that the appropriatefee is paid to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, tel: (978) 750-8400; Internet:.iiiAWS D10.11M/D10.11:2007Statement on the Use of American Welding Society StandardsAll standards (codes, specifications, recommended practice
7、s, 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 National Standards are either incorporated in, ormade part of, d
8、ocuments 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 approved by the governmental body having statutory jurisdict
9、ion 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 in or deviations from requirementsof an AWS standard must
10、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. While AWS administers the processand establishes rules to
11、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 or to property, or other damages of any nature whatsoeve
12、r, 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 informationpublished herein.In issuing and making this standard ava
13、ilable, AWS is not undertaking to render professional or other services for or onbehalf 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 rely on his or her own independent judgment or, as appropriate,
14、 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.Publication of this standard does not authorize infringement of
15、 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 this standard.Finally, AWS does not monitor, police, or enforc
16、e 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 interpretations of any of the technical requirements of this sta
17、ndard may only be obtained by sending a request,in writing, to the Managing Director, Technical Services Division, American Welding Society, 550 N.W. LeJeune Road,Miami, FL 33126 (see Annex A). With regard to technical inquiries made concerning AWS standards, oral opinionson AWS standards may be ren
18、dered. However, such opinions represent only the personal opinions of the particularindividuals giving them. These individuals do not speak on behalf of AWS, nor do these oral opinions constitute officialor unofficial opinions or interpretations of AWS. In addition, oral opinions are informal and sh
19、ould not be used as asubstitute for an official interpretation.This standard is subject to revision at any time by the AWS D10 Committee on Piping and Tubing. It must be reviewedevery five years, and if not revised, it must be either reaffirmed or withdrawn. Comments (recommendations, additions,or d
20、eletions) and any pertinent data that may be of use in improving this standard are required and should be addressedto AWS Headquarters. Such comments will receive careful consideration by the AWS D10 Committee on Piping andTubing and the author of the comments will be informed of the Committees resp
21、onse to the comments. Guests areinvited to attend all meetings of the AWS D10 Committee on Piping and Tubing to express their comments verbally.Procedures for appeal of an adverse decision concerning all such comments are provided in the Rules of Operation ofthe Technical Activities Committee. A cop
22、y of these Rules can be obtained from the American Welding Society, 550N.W. LeJeune Road, Miami, FL 33126.This page is intentionally blank.ivAWS D10.11M/D10.11:2007vAWS D10.11M/D10.11:2007Personnel*AdvisorAWS D10 Committee on Piping and TubingD. J. Connell, Chair Detroit EdisonM. P. Lang, 1st Vice C
23、hair United Association, Local 501W. F. Newell, Jr., 2nd Vice Chair W. F. Newell and Associates, IncorporatedB. C. McGrath, Secretary American Welding SocietyT. Anderson ESAB Welding and Cutting ProductsR. E. Avery Nickel Development InstituteW. L. Ballis ConsultantA. S. Beckett Alyeska Pipeline Ser
24、vice Company*C. J. Bishop Medical Gas Management, IncorporatedC. J. Bloch Boyle Energy Services therefore, eachsystem must be used independently.To identify nominal pipe sizes in both SI and U.S. Cus-tomary Units, the following designations are used:1. DN (Diameter Nominal) is the SI designation.2.
25、NPS (Nominal Pipe Size) is the U.S. Customarydesignation.2. Normative ReferencesThe following standards contain provisions which,through reference in this text, constitute provisions ofthis AWS standard. For undated references, the latest edi-tion of the referenced standard shall apply. For dated re
26、f-erences, subsequent amendments to, or revisions of, anyof these publications do not apply.AWS Documents:11. AWS A3.0, Standard Welding Terms and Definitions2. AWS A5.1/A5.1M, Specification for Carbon SteelElectrodes for Shielded Metal Arc Welding3. AWS A5.5/A5.5M, Specification for Low AlloySteel
27、Electrodes for Shielded Metal Arc Welding4. AWS A5.12/A5.12M, Specification for Tungsten andTungsten Alloy Electrodes for Arc Welding and Cutting5. AWS A5.30/A5.30M, Specification for Consum-able Inserts6. AWS A5.32/A5.32M, Specification for WeldingShielding Gases7. AWS C5.5/C5.5M, Recommended Pract
28、ices forGas Tungsten Arc Welding8. AWS C5.10/C5.10M, Recommended Practices forShielding Gases for Welding and Plasma Arc Cutting9. AWS D10.4, Recommended Practices for WeldingAustenitic Chromium-Nickel Stainless Steel Piping andTubing1AWS standards are published by the American WeldingSociety, 550 N
29、.W. LeJeune Road, Miami, FL 33126.Guide for Root PassWelding of Pipe Without BackingAWS D10.11M/D10.11:2007210. AWS D10.6/D10.6M, Recommended Practices forGas Tungsten Arc Welding Titanium Piping and Tubing11. AWS D10.7M/D10.7, Guide for the Gas ShieldedArc Welding of Aluminum and Aluminum Alloy Pip
30、e12. AWS D10.8, Recommended Practices for Weld-ing Chromium-Molybdenum Steel Piping and Tubing13. AWS D10.12M/D10.12, Guide for Welding MildCarbon Steel Pipe14. AWS F1.1M, Methods for Sampling AirborneParticulates Generated by Welding and Allied Processes15. AWS F1.3, Sampling Strategy Guide for Eva
31、luat-ing Contaminates in the Welding Environment16. AWS F3.2M, Ventilation Guide for Welding17. AWS F4.1, Recommended Safe Practices forPreparation for Welding and Cutting of Containers andPiping18. AWS, Safety and Health Fact SheetsAmerican National Standards Institute (ANSI) Documents:21. ANSI Z49
32、.1, Safety in Welding, Cutting, and AlliedProcesses (published by American Welding Society)2. NSI Z87.1, Practice for Occupational and Educa-tional Eye and Face Protection3. Terms and DefinitionsTerms used in this document should be interpreted inaccordance with AWS A3.0, Standard Welding Termsand D
33、efinitions, except for those not defined by that stan-dard or where these terms require further definition toclarify their usage in this standard.air-cooled torch. A nonstandard term for a gas cooledtorch.gas-cooled torch. A welding torch where the primarycooling medium of the torch is the flow of s
34、hieldinggas.keyhole welding. A standard term for the technique inwhich a concentrated heat source penetrates partiallyor completely through a workpiece, forming a hole(keyhole) at the leading edge of the weld pool. As theheat source progresses, the molten metal fills inbehind the hole to form the we
35、ld bead.2ANSI standards are published by the American National Stan-dards Institute, 25 West 43rd Street, 4th Floor, New York, NY10036-7406.nozzle weld. A nonstandard term for a weld between twopipes in which a hole is made in one pipe, and theother pipe is welded onto the first pipe at the hole at
36、apredetermined angle to provide an alternate fluid path.purge. A standard term for the introduction of a gas toremove contaminants from a system or provide back-ing during welding.purge caps. Devices made of any suitable material thatcan be used to seal the ends of pipes for purging.purge dams. Barr
37、iers made of any suitable material thatcan be placed inside pipes to contain the purge gaseswithin the weld area. They may be water soluble or ofsome other type.walking-the-cup. A technique for manipulating thetorch when manually welding groove welds. With thistechnique, the electrode extension is a
38、djusted to allowthe proper arc length while the edge of the shieldinggas nozzle rests on both groove faces of the joint. Thetorch is manipulated using a wrist motion in which thenozzle (cup) is rotated at a slight angle to the axis ofthe root opening, increased pressure is exerted on theleading groo
39、ve face while the nozzle is rotated caus-ing forward progression. Subsequently the nozzle isrotated and increased pressure is exerted on theopposing groove face. The nozzle is again rotatedcausing further forward progression. This motion isrepeated so that the cup appears to be “walking” alongthe gr
40、oove faces while the arc oscillates smoothlyacross the joint.water-cooled torch. A welding torch where the primarycooling medium is the flow of water or other liquidcoolant through the torch.4. Preparations for Welding4.1 Cleanliness. Cleanliness is important in all weldingoperations, but it is espe
41、cially important in root passwelding. Cleaning should be done on the groove facesand a minimum of 25 mm 1 in of the base metal onboth the inside and outside surfaces of the pipe. All partsof the joint should be free of grease and oil, which shouldbe removed by use of a suitable solvent. A suitable s
42、ol-vent is one that does not leave a residue and is not harm-ful to the welder or to the weldment. Most solventsrequire good ventilation, and many are flammable; there-fore, proper precautions should be taken. Grinding orother mechanical means should be used to remove allpaint, scale, rust, and dirt
43、.Grinding and cleaning operations should be done justprior to welding. After cleaning, the pipe should be han-dled so as to preserve cleanliness.AWS D10.11M/D10.11:200734.2 Purging4.2.1 Purging Applications. An internal gas purge isrequired for stainless and nonferrous piping systems(except aluminum
44、) if a smooth root surface is to beobtained. Carbon steels and low alloy steels containingless than 5% chromium can be welded using an open rootgroove without the use of an internal gas purge. How-ever, purging of joints is highly recommended when thechromium content of the weld metal exceeds 2% or
45、whenusing a consumable insert since purging reduces theoccurrence of defects and the excessive oxidation of theresultant root bead. Inert backing gas should always beused for consumable inserts of any material other thancarbon steel and when using Class 1 or 2 inserts.It should be noted that purging
46、 will increase weldingspeed significantly when used during welding steels thatdo not normally require purging, such as carbon and lowalloy steel.4.2.2 Purging Gases. Argon is most often used forinternal purging and may be safely used for all materials.Helium may also be used for all materials, altho
47、ugh it ismore expensive than argon. For some materials, nitrogenis a suitable purge gas. Nitrogen can be used at lowercost than argon for specific applications, but it shouldbe demonstrated as suitable by testing prior to use inproduction.The purging gases should be specified according to AWSA5.32/A
48、5.32M, Specification for Welding ShieldingGases, or AWS C5.10, Recommended Practices forShielding Gases for Welding and Plasma Arc Cutting.Argon (AWS A5.32/A5.32M Class SG-A), helium (SG-He), and nitrogen (SG-N) should have a purity of betterthan 99.995% and have a dew point of 51C 67F, orlower.The
49、purging procedures in this document are based onthe use of argon as the purging gas. If nitrogen or heliumis used, modifications to the purging procedure may benecessary because both gases are less dense than argon.4.3 Purge Gas Containment4.3.1 General Requirements and Some Contain-ment Methods. Purging requires an entrance opening,through which the purge gas can enter the weld joint areaat a controlled rate, and an exit opening, through whichoxygen-containing gas can leave. Purge gas hoses shouldnot be rubber or other porous material since these areable to aspirate air when high fl
