1、 Recommendations for tube end welding PUBLICATION 143 Edition 2 Released by IHS. NOT FOR RESALE EEMUA Copyright 2017 The Engineering Equipment and Materials Users Association Recommendations for tube end welding Publication 143 Edition 2 Copyright 2017 The Engineering Equipment and Materials Users A
2、ssociation. A company limited by guarantee. Registered in England. Company number 477838. All rights reserved. ISBN 978 0 85931 217 2 Imprint reference 02-2017 First published 02-2017 Registered and Trading Address: EEMUA, Second Floor, 16 Black Friars Lane, London EC4V 6EB Telephone: +44 (0)20 7488
3、 0801 Email: saleseemua.org Website: www.eemua.orgIV Recommendations for tube end welding Publication 143 EEMUA Copyright 2017 The Engineering Equipment and Materials Users Association Contents Preface VII 1. Scope .1 1.1 Acronyms and definitions 1 1.2 Convention . 1 2. Welding process and joint det
4、ail 3 2.1 Manual processes . 3 2.2 Automatic and semi-automatic processes 3 2.3 Acceptable welding processes . 3 2.4 Joint types . 3 2.4.1 Expansion only (no welding) 3 2.4.2 Expansion and seal-welding . 4 2.4.3 External fillet weld 4 2.4.4 External butt and fillet weld 5 2.4.5 Internal fillet weld
5、. 5 2.4.6 Castellated . 6 2.4.7 Full penetration internal butt weld . 6 3. Qualication of welding procedure 7 3.1 Introduction . 7 3.2 Test samples 7 3.3 Non-destructive testing 7 3.3.1 Visual examination . 7 3.3.2 Radiographic examination . 7 3.4 Destructive testing . 7 3.4.1 Weld strength tests 7
6、3.4.2 Macroexamination and hardness tests . 8 3.4.3 Ferrite test 9 3.4.4 Corrosion test 9 4. Qualication of welders and welding operators 11 4.1 Test samples 11 4.2 Test purpose 11 4.3 Previous qualification .11 4.4 Operators deemed competent .11V Recommendations for tube end welding Publication 143
7、 EEMUA Copyright 2017 The Engineering Equipment and Materials Users Association 5. Preparation of tubes and tube-plates . 13 5.1 Cleaning .13 5.2 Tube holes 13 5.3 Assembly .13 6. Tube location . 15 6.1 Tube fit accuracy .15 6.2 Preparation for welding 15 7. Preheat and interpass temperature 17 7.1
8、General 17 7.2 Practical limits .18 7.3 Weld interruption .18 7.4 Preferred means of preheating .18 8. Welding 19 8.1 General 19 8.2 Welding individually .19 8.3 Distortion minimisation 19 8.4 Autogenous welding 19 8.5 Additional controls.19 9. Post-weld heat treatment 21 9.1 General 21 9.2 Heating
9、rates .21 9.3 Additional welding 21 10. Quality control and health and safety . 23 10.1 General .23 10.2 Samples .23 10.3 Examination of materials .23 10.3.1 Tubes .23 10.3.2 Tube-plates 23 10.4 Health and Safety .23VI Recommendations for tube end welding Publication 143 EEMUA Copyright 2017 The Eng
10、ineering Equipment and Materials Users Association 11. Cleaning and inspection . 25 11.1 General .25 11.2 Dye penetrant testing .25 11.3 Other .25 12. Leak detection . 27 12.1 General .27 12.2 Air testing .27 12.3 Gas leak testing .27 12.4 Other leak testing .27 12.5 Leak investigation 27 13. Repair
11、s . 29 13.1 Leaks 29 13.2 Qualified procedure 29 13.3 Cause of defect 29 14. Tube expansion . 31 14.1 General .31 14.2 Location .31 14.3 Equipment .31 14.4 Tube wall thinning 31 14.5 Bores 31 15. Pressure testing 33 15.1 Cleaning 33 15.2 Final acceptance pressure test .33 15.3 Leaks 33 15.4 Repair 3
12、3 16. Draining and dewatering . 35 16.1 General .35 16.2 Heating 35 17. Supervision and inspection 37 17.1 General .37 17.2 Inspection and Test Plan (ITP) .37VII Recommendations for tube end welding Publication 143 EEMUA Copyright 2017 The Engineering Equipment and Materials Users Association 18. Re
13、cords 39 References 41 Figures Figure 1 Expansion only.3 Figure 2 Expansion and seal-welding 4 Figure 3 External fillet weld . 4 Figure 4 External butt and fillet weld . 5 Figure 5 Internal fillet weld 5 Figure 6 Castellated 6 Figure 7 Full penetration internal butt weld 6 Figure 8 Weld strength tes
14、ts .8 Tables Table 1 Preheat and interpass temperature 17VIII Recommendations for tube end welding Publication 143 EEMUA Copyright 2017 The Engineering Equipment and Materials Users AssociationIX Recommendations for tube end welding Publication 143 EEMUA Copyright 2017 The Engineering Equipment and
15、Materials Users Association Publication 143 was first published under the EEMUA banner in 1985 following the merger of the Engineering Equipment Users Association (EEUA) and the Oil Companies Materials Association (OCMA). The Publication was originally OCMA Specification No. TEW-1: Recommendations f
16、or tube end welding: tubular heat transfer equipment, Part 1 Ferrous materials. It was written by OCMAs Welding Panel with assistance from the Heat Transfer Society. A joint meeting was convened in October 1966 of members of OCMA welding panel and representatives of the Heat Transfer Society to exch
17、ange information on experience gained in making welded joints between heat exchanger tubes and tube-plates. It was the opinion of that meeting that an urgent need existed for standardised procedures to be established for the design, fabrication, inspection and testing of these and similar components
18、. At that time, there was no national or international standard in existence that adequately covered this important subject. Members pooled their knowledge and experience, and co-operated in preparing a recommended practice for tube end welding and testing. Such a recommendation could then be used a
19、s a basis for specifying requirements for the oil, chemical and other industries. In the interim, codes such as ASME BPVC VIII, ASME IX and particularly EN ISO 15614-8:2002 have covered much of the same ground. This new Second Edition of EEMUA 143 takes ISO 15614-8:2016 Specification and qualificati
20、on of welding procedures for metallic materials - Welding procedure test Part 8: Welding of tubes to tube-plate joints as the primary source material with some additions where it was felt that the standard required further clarification, or does not address the topic sufficiently. PrefaceX Recommend
21、ations for tube end welding Publication 143 EEMUA Copyright 2017 The Engineering Equipment and Materials Users Association1 Recommendations for tube end welding Publication 143 EEMUA Copyright 2017 The Engineering Equipment and Materials Users Association This Publication supplements the requirement
22、s of ISO 15614-8:2016 for all tube to tube-plate welding. However, it does not cover joints made purely by mechanical means, e.g. expansion. 1.1 Acronyms and denitions The following list of acronyms used in this Publication are defined below: ANSI American National Standards Institute ASME American
23、Society of Mechanical Engineers ASTM American Society for Testing and Materials AWS American Welding Society BPVC Boiler and Pressure Vessels Code EN European Standards GTAW Gas Tungsten Arc Welding HAZ Heat Aected Zone ID Inside Diameter IEC International Electro-technical Commission IIS Italian In
24、stitute of Welding IIW International Institute of Welding ISO International Organization for Standardization ITP Inspection and Test Plan NDT Non Destructive Testing OD Outside Diameter TEMA Tubular Exchanger Manufacturers Association UTS Ultimate Tensile Strength 1.2 Convention This Publication ref
25、ers to parts of other specifications as section and to its own contents as clause. 1. Scope2 Recommendations for tube end welding Publication 143 EEMUA Copyright 2017 The Engineering Equipment and Materials Users Association3 Recommendations for tube end welding Publication 143 EEMUA Copyright 2017
26、The Engineering Equipment and Materials Users Association 2.1 Manual processes Earlier editions of this Publication included detailed design criteria based on IIS/IIW recommendations that represented welding practice at that time, including details of suitable joint sizes relative to individual, mos
27、tly manual, welding processes. This level of detail is not included in this edition as the majority of welding will be automated. 2.2 Automatic and semi- automatic processes Modern welding techniques for tube-to-tube-plate welding predominantly use automatic welding machines that are capable of cons
28、istent results and can accurately reproduce the weld joints performed during qualification testing. However, it is still sometimes necessary to use manual or semi-automatic processes, particularly in the case of large diameter tubes. 2.3 Acceptable welding processes All welding processes are permiss
29、ible, provided that acceptable results and appropriate metallurgical properties can be achieved during procedure qualification and reproduced consistently in production. This Publication does not prohibit the use of any suitable welding process. 2.4 Joint types No joint types are prohibited but the
30、main joint types can be summarised as follows: 2.4.1 Expansion only (no welding) Expansion-only joints are outwith this Publication and not usually permitted for process service due to the risk of crevice corrosion at the tube-to- tube-plate edge. Figure 1 Expansion only 2. Welding process and joint
31、 detail4 Recommendations for tube end welding Publication 143 EEMUA Copyright 2017 The Engineering Equipment and Materials Users Association 2.4.2 Expansion and seal-welding For certain applications, and where specified in the Purchase Order, expansion into ring groove(s), coupled with seal-welding
32、may be utilised. This method introduces risks if the tube is fully expanded prior to welding as gases evolved/ released during welding will not be able to escape from the root side of the joint. Therefore, partial expansion to secure the tube, followed by welding and final expansion is recommended.
33、When this method is applied, all criteria of this Publication and ISO 15614-8 apply with the exception of the 0.9t weld throat requirement. Figure 2 Expansion and seal-welding 2.4.3 External llet weld The tube passes completely through and extends beyond the tube-plate, allowing a fillet weld to be
34、performed on the outside diameter of the tube. The fillet leg size can exceed the tube wall thickness and is normally specified as 1.4t minimum to provide a weld throat thickness at least equal to the tube wall thickness. This method is recommended for manual and semi-automatic welding processes. Fi
35、gure 3 External llet weld L t5 Recommendations for tube end welding Publication 143 EEMUA Copyright 2017 The Engineering Equipment and Materials Users Association 2.4.4 External butt and llet weld This configuration is similar to the external fillet weld, but a bevel is cut into the tube-plate allow
36、ing the resulting butt weld throat to be supplemented by the fillet weld. The advantage of this design is that the overall weld volume is reduced and there is less chance of burning through the tube wall. There is a risk of lack of fusion at the weld root on the tube-plate due to the larger wall thi
37、ckness, particularly for manual and semi-automatic welding. Figure 4 External butt and llet weld 2.4.5 Internal llet weld Internal fillet welds are commonly applied using manual, semi-automatic, or automatic welding processes. There is a risk of inadequate weld throat thickness as the fillet leg len
38、gth cannot exceed the tube wall thickness. As a result of this ISO 15614-8 table 4 item 16 has a weld throat acceptance criterion for the macrosections of 0.9t instead of the 1t that would be expected for a full strength joint. Push-through tensile tests are more likely to fail in the weld as a resu
39、lt of this reduced throat thickness (see clause 3.4 Weld Strength Tests). There is an additional risk of excessive weld penetration into the tube ID when using this joint configuration and trying to obtain sufficient weld throat thickness. Figure 5 Internal llet weld L a = t t b t b + 0.7L a t6 Reco
40、mmendations for tube end welding Publication 143 EEMUA Copyright 2017 The Engineering Equipment and Materials Users Association 2.4.6 Castellated A U-Groove is machined into the tube-plate to provide a joint that appears to be a concentric tube outside the tube. The advantage of this configuration i
41、s that the heat sink on the tube-plate side is reduced to be comparable with the tube. Furthermore, welding distortion of the tube-plate is minimised. A disadvantage of this joint configuration is that the weld bead profile becomes critical to achieving sufficient weld throat. Figure 6 Castellated 2
42、.4.7 Full penetration internal butt weld A U-Groove is machined into the tube-plate to provide a joint that appears to be a matching tube on the tube side of the tube-plate. This allows a full penetration weld to be performed from the inside of the tube and will normally require an additional shield
43、ing gas to be applied from the outside of the tube. The preferred geometry on the right includes a recess that centres the tube and provides additional weld metal for autogenous welds (though see clause 8.4 of this Publication). Although this configuration is shown without a root gap, a gap can be i
44、ncorporated to allow filler metal addition by fed wire or consumable insert ring. This specialist geometry is employed to eliminate crevices on both side of the tube-plate, particularly for liquid/liquid heat exchangers. It is also the only joint type that permits full volumetric NDT. Figure 7 Full
45、penetration internal butt weld D W t = D = 2t W = t t7 Recommendations for tube end welding Publication 143 EEMUA Copyright 2017 The Engineering Equipment and Materials Users Association 3.1 Introduction Qualification of weld procedures should be in accordance with ISO 15614-8 as modified by this Pu
46、blication. The Purchaser shall be given sufficient notice to enable them or their representative to witness all weld procedure qualification tests. At the discretion of the Purchaser, the results of previously 3rd party-authenticated procedure tests may be acceptable. 3.2 Test samples All tubes used
47、 for procedure testing shall be of the same diameter, wall thickness and nominal chemical composition as those proposed for production. Tube-plate material to be used for the procedure test shall also be of the same nominal composition and supply condition (including product form and heat treatment)
48、 as that to be used in manufacture. Qualification range shall be in accordance with ISO 15614-8 Table 5 (section 9.3.2), except as follows: When the thickness of the tube-plate (t 2 ) is less than 35mm, the qualified thickness range is 0.75t 2 1.5t 2 ; The tube nominal diameter and wall thickness fo
49、r mechanised / automatic welding shall be the size used for qualification; If tube expansion after welding is specified, it may be necessary for a sample of full plate thickness to be employed (see clause 14 of this Publication). 3.3 Non-destructive testing 3.3.1 Visual examination A visual examination of the welds shall show uniform contour without excessive reinforcement with the bores of the tubes free from any spatter, obstruction, weld spillage or overfill, which is considered to be detrimental. 3.3.2 Radiographic examination Refer
