《CGA-C-3-2005.pdf》由会员分享，可在线阅读，更多相关《CGA-C-3-2005.pdf（30页珍藏版）》请在三一文库上搜索。
1、 CGA C-32005 STANDARDS FOR WELDING ON THIN-WALLED, STEEL CYLINDERS SEVENTH EDITION COMPRESSED GAS ASSOCIATION, INC. 4221 Walney Road, 5th Floor Chantilly, VA 20151 Phone: 703-788-2700 Fax: 703-961-1831 E-mail: -,-,- PAGE ii COMPRESSED GAS ASSOCIATION, INC. CGA C-32005 PLEASE NOTE: The information c
2、ontained in this document was obtained from sources believed to be reliable and is based on technical information and experience currently available from members of the Compressed Gas Association, Inc. and others. However, the Association or its members, jointly or severally, make no guarantee of th
3、e results and assume no liability or responsibility in connection with the information or suggestions herein contained. Moreover, it should not be assumed that every acceptable commodity grade, test or safety procedure or method, precaution, equipment or device is contained within, or that abnormal
4、or unusual circumstances may not warrant or suggest further requirements or additional procedure. This document is subject to periodic review, and users are cautioned to obtain the latest edition. The Associa- tion invites comments and suggestions for consideration. In connection with such review, a
5、ny such comments or suggestions will be fully reviewed by the Association after giving the party, upon request, a reasonable op- portunity to be heard. Proposed changes may be submitted via the Internet at our web site, . This document should not be confused with federal, state, provincial, or munic
6、ipal specifications or regulations; insurance requirements; or national safety codes. While the Association recommends reference to or use of this document by government agencies and others, this document is purely voluntary and not binding. A listing of all publications, audiovisual programs, safet
7、y and technical bulletins, and safety posters is available via the Internet at our website at . For more information contact CGA at Phone: 703-788-2700, ext. 799. E-mail: . Docket 06-54 Cylinder Specifications Committee NOTETechnical changes from the previous edition are underlined. NOTEAppendix D (
8、Normative) is a requirement. NOTEAppendices A, B, C, and E (Informative) are for information only. SEVENTH EDITION: 2005 SIXTH EDITION: 2003 FIFTH EDITION: 2000 FOURTH EDITION: 1994 2005 BY THE COMPRESSED GAS ASSOCIATION, INC. 4221 WALNEY ROAD, 5TH FLOOR, CHANTILLY, VA 20151 Printed in U.S.A. -,-,-
9、CGA C-32005 COMPRESSED GAS ASSOCIATION, INC. PAGE iii Contents Page 1 Introduction.1 2 Scope .1 2.1 Procedure qualification1 2.2 Operator qualification 1 2.3 Container production acceptance1 2.4 Radiographic inspection1 3 Procedure qualification.1 3.1 Applicability1 3.2 Procedure specification.1 3.3
10、 Welding procedures.2 3.4 Base material.2 3.5 Positions of welds2 3.6 Type, number, and method of preparation of test specimens.3 3.7 Methods of testing specimens and acceptable test results.4 3.8 Records.4 3.9 Essential variables 4 4 Operator qualification .4 4.1 Applicability4 4.2 Welding procedur
11、es.4 4.3 Base material.5 4.4 Positions of welds5 4.5 Type, number, and method of preparation of test specimens.5 4.6 Methods of testing specimens and acceptable test results.5 4.7 Retests 5 4.8 Period of effectiveness6 4.9 Records.6 4.10 Essential variables 6 5 Container production acceptance.7 5.1
12、Location of details for required tests7 5.2 Production lots.7 5.3 Radiographic examination.7 6 Radiographic inspection.7 6.1 Applicability7 6.2 Preparation7 6.3 Terminology.8 6.4 Darkroom facilities.8 6.5 Film viewing facilities.8 6.6 Film processing .8 6.7 Penetrameters.8 6.8 Film identification an
13、d inspection data.10 6.9 Selection of technique.10 6.10 Limits of acceptability 11 6.11 Retests 12 6.12 Retention of radiographs.12 7 Container repairapplicability.12 -,-,- PAGE iv COMPRESSED GAS ASSOCIATION, INC. CGA C-32005 8 Test methods12 8.1 Positions of welds12 8.2 Tension test (transverse to
14、weld) 12 8.3 Flattening test (on cylindrical section) .14 8.4 Flattening test (on sphere).15 8.5 Root-break test15 8.6 Macro-etch test15 8.7 Guided-bend test.16 9 Assignment of electrodes.20 10 References.20 Tables Table 1Composition limits for material groupings2 Table 2Procedure qualification test
15、 specimens.3 Table 3Operator qualification test specimens .6 Table 4Assignment of electrodes and welding rods for procedures and operator qualification 20 Figures Figure 1Sample penetrameter.9 Figure 2Suggested format for radiograph documentation.10 Figure 3Position of welds 13 Figure 4Specimen for
16、tension test.14 Figure 5Specimen for guided-bend test 16 Figure 6Standard guided-bend test jig 17 Figure 7Alternate guided-bend test jig.18 Figure 8Illustrated methods for alternate guided-bend test.19 Appendices Appendix ARecommended form for procedure qualification record (Informative).22 Appendix
17、 BRecommended form of welding procedure specification (Informative) .23 Appendix CRecommended form for manufacturers record of welder or welding operator qualification tests (Informative) .24 Appendix DDimensional tolerances (Normative).25 Appendix ETypical weld joints (Informative)26 -,-,- CGA C-32
18、005 COMPRESSED GAS ASSOCIATION, INC. PAGE 1 1 Introduction The Compressed Gas Association, Inc. (CGA) has established these standards to promote uniformity and ser- viceability of compressed gas containers produced under the specifications of the U.S. Department of Trans- portation (DOT) and Transpo
19、rt Canada (TC) for the manufacturers of welded steel compressed gas containers and for the inspectors who can be called upon to qualify welding on such containers. Establishment of stan- dards for procedure and operator qualification and for radiographic inspection was necessary to define accept- ab
20、le parameters concerning the gauge of materials, i.e., thickness, used in compressed gas containers of 900 psig (6210 kPa) maximum service pressure.1, 2 2 Scope This publication addresses normal production welding techniques and is not intended to cover all welding. When evaluating techniques other
21、than those covered in detail in this publication, reference to ASME Boiler and Pressure Vessel Code, Section IX, “Welding and Brazing Qualifications,” might be appropriate 2. This ASME Code applies to essential variables and material types. These standards are recommended as being applicable to TC/D
22、OT specification containers of 900 psig (6210 kPa) maximum service pressure, 454 kg (1000 lb) maximum water capacity, and maximum wall thick- ness of 0.375 in (9.53 mm). These standards include the following subjects: 2.1 Procedure qualification Standards relating to welding procedure require that e
23、ach procedure be qualified by tests to demonstrate that adequate soundness, strength, and ductility of joints are obtainable under the welding conditions specified. 2.2 Operator qualification Standards relating to the welding operator require that each operator be qualified by tests that adhere to a
24、n approved welding procedure to demonstrate that the operator possesses acceptable welding ability. 2.3 Container production acceptance Standards relating to the use of sampling tests apply to qualifying production lots for acceptance by the certify- ing inspector. 2.4 Radiographic inspection Standa
25、rds relating to radiographic inspection apply to details of radiographic inspection technique that conform to currently recognized industrial practice not found in container specifications. 3 Procedure qualification 3.1 Applicability Procedures for all welding of pressure parts and attachments to pr
26、essure parts of compressed gas containers shall be qualified in accordance with these standards. 3.2 Procedure specification The procedures of welding to be followed in construction shall be established and recorded by the manufac- turer as a procedure specification. Recommended forms for these proc
27、edures are given in Appendix A and 1 kPa shall indicate gauge pressure unless otherwise noted as (kPa, abs) for absolute pressure or (kPa, differential) for dif- ferential pressure. All kPa values are rounded off per CGA P-11, Metric Practice Guide for the Compressed Gas Industry 1. 2 References are
28、 shown by bracketed numbers and are listed in order of appearance in the reference section. -,-,- PAGE 2 COMPRESSED GAS ASSOCIATION, INC. CGA C-32005 Appendix B. It is not necessary that these exact forms be used, but the information contained therein shall be included in any alternate form used. If
29、 any changes are made in a procedure, the procedure specification shall be revised or amended to show the changes. If certain changes are made in a procedure specification, requalification of the revised procedure shall be required as stated in 3.9. 3.3 Welding procedures Welding procedures on speci
30、mens prepared for qualification tests shall comply in all respects with the proce- dure specification. For qualification of a manual welding process, the container or test plate shall be manually welded. For qualification of an automatic welding process, the container or test plate shall be welded b
31、y the production procedure using identical equipment in production with respect to position of work; protection of hot metal; and automatic control of preheat, feed, speed, current, oscillation, interruption, rate of cooling, etc. Quali- fication of automatic welding on one type of equipment shall n
32、ot qualify the process on another type of equip- ment that lacks any single element of control provided on the first. 3.4 Base material Base materials for welding of qualification test specimens shall be of the same alloy group as the production materials. The grouping of materials for procedure qua
33、lification shown in Table 1 is made on the basis of hardenability characteristics. Base materials of different analysis within a group may be indiscriminately substi- tuted for a material that was used in the qualification test. Table 1Composition limits for material groupings Group Alloy family C M
34、n P S Si Cr Ni Mo Cb Cu Ti I Carbon steels 0.25 1.00 0.045 0.05 0.50 0.04 II Carbon- manganese steel 0.25 1.00/ 1.65 0.04 0.05 0.50 0.04 0.40 III Alloy steels 0.25/ 0.35 0.40/ 0.90 0.04 0.05 0.20/ 0.35 0.80/ 1.10 0.15/ 0.25 IV Austenitic stainless steels 0.08 2.00 0.045 0.03 1.00 16.0/ 20.0 8.0/ 14.
35、0 2.0/ 3.0 10x % C min 1.0% max 5x % C min 0.6% max NOTES 1 Chemical analysis limits are given in percent. All single value entries are maximums. 2 Addition of unspecified elements to obtain alloying effect is not permitted. The test material to be used for qualification of girth welds shall be form
36、ed to the smallest container diameter which is to be qualified. This also qualifies all larger diameters. Diameter is not a consideration for longitudinal or attachment welds. The thickness of the test material shall be within 20% and +50% of the material to be qualified. The qualification test mate
37、rial shall be in the same heat-treated condition before testing as the production mate- rial to be welded. If the production material is to be heat treated after welding, the qualification test material shall be given the same heat treatment before physical tests are conducted. 3.5 Positions of weld
38、s The positions of welds used in welding of qualification test specimens and production containers shall be re- stricted to flat and horizontal positions in accordance with welding positions, which are shown in Section 8. -,-,- CGA C-32005 COMPRESSED GAS ASSOCIATION, INC. PAGE 3 3.6 Type, number, an
39、d method of preparation of test specimens 3.6.1 Type Each type of welded joint in a container shall be tested for each procedure to be qualified. 3.6.2 Number Test specimens shall be taken for each type of joint as specified in Table 2. NOTECylinders can contain heads that are convex to pressure. Th
40、ese cylinders can contain a joggle butt or fillet weld joint. In turn, there might not be sufficient material to conduct a guided-bend or face-bend test. In this case, a macro-etch of the weld is an acceptable practice for meeting the criteria of Table 2. 3.6.3 Method of preparation The number of te
41、st specimens and method of preparation of specimens shall be in accordance with applicable references in Table 2. Table 2Procedure qualification test specimens Type of joint Type of test required Purpose of test Number of specimens Method of preparation testing and required test results Longitudinal
42、 groove welded butt Tension (transverse to weld) Guided-bend root-bend Guided-bend face-bend Strength Soundness Soundness 2 2 2 See 8.2 See 8.7 See 8.7 Butt weld of seam in sphere Companion bar reduced section tension (transverse to weld) Flattening 1) Guided-bend root-bend 2) Guided-bend face-bend
43、2) Strength Ductility Soundness Soundness 2 1 2 2 See 8.2 See 8.4 See 8.7 See 8.7 Circumferential welded butt Flattening 1) Guided-bend root-bend 2) Guided-bend face-bend 2) Ductility Soundness Soundness 2 2 2 See 8.3 See 8.7 See 8.7 Circumferential welded lap or joggle butt Flattening 1) Guided-ben
44、d root-bend 2) Ductility Soundness 2 2 See 8.3 See 8.7 Welded attachments on pressure parts Root-break 3) Soundness 2 See 8.5 Fillet for attachment of bosses, pads, or heads Macro-etch Soundness 2 See 8.6 NOTES 1 For the order of removal of test specimens on circumferential seams, each pair of test
45、specimens shall be taken 180 degrees apart. On longitudinal seams, each pair of test specimens shall be taken not less than 50% of the seam length apart. 2 For drawings of typical weld joints, see Appendix E. 1) Performed only if the cylinder specification requires a flattening test. 2) A root-break
46、 test or radiographic inspection of the full qualification test weld length may be substituted at the manufac- turers option. 3) If root-break specimens will not fracture in the joint, macro-etch tests may be substituted. -,-,- PAGE 4 COMPRESSED GAS ASSOCIATION, INC. CGA C-32005 3.7 Methods of testi
47、ng specimens and acceptable test results Methods of testing specimens and acceptable test results shall be in accordance with applicable references in Table 2. 3.8 Records Records of test results shall be kept by the manufacturer and shall be available to those authorized to examine them. Recommende
48、d forms for recording the results of both the procedure qualification and operator qualifica- tion tests are given in Appendix A and Appendix C. 3.9 Essential variables The welding procedure shall be set up as a new procedure specification and shall be completely requalified when any of the following changes are made in the procedure: A change in the specification of either or both of the base metals to be welded from one group number to another group number as shown