1、BRITISH STANDARD Brazing - Procedure approval BS EN 131342000 The European Standard EN 13134:2000 has the status of a British Standard ICs 26.160.60 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYEIGm LAW STD-ES1 BS EN L3L34-ENGL 2000 6 I1624669 0874510 743 BS EN 131342000 National for
2、eword This British Standard is the official English language version of EN 13134:2000. Together with BS EN 13133:2000 it supersedes BS 172341988 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee WEW19, Brazing and bronze welding, which has the responsib
3、ility to: - aid enquirers to understand the text; - present to the responsible European committee any enquiries on the - monitor related international and European developments and promulgate interpretation, or proposals for change, and keep the UK interests informed; them in the UK. A list of organ
4、izations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement internationai or European publications referred to in this document may be found in the BSI Stan such standards usually require that special processes be carried
5、 out in accordance with written procedure specifications. This standard defines the content for the brazing procedure specifications which is considered to fulfil the requirements in current standards for quality systems as regards procedure specifications. Preparation of a brazing procedure specifi
6、cation records the necessary instructions for evaluation but does not in itself ensure that the resulting brazes fulfil the service requirements. Some deviations can be evaluated by non-destructive methods on the finished product but others, e.g. metallurgical deviations, cannot. This has resulted i
7、n the establishment of a set of rules for approval of the brazing procedure prior to the release of the specification to actual production. Guidelines for the practical application of brazing procedure approval are given in annex A. Furthermore, this standard allows for brazing procedure approval to
8、 be related to previous experience of similar applications. Many manufacturers have considerable experience in fabricating brazed structures. Brazed components and structures may have been supplied for a variety of applications and have performed satisfactorily over a period of time in service. If t
9、his experience is traceable and verifiable, this standard provides a route for brazing procedure approval based on this experience. Q BSI 10-2000 STD-BSI BS EN L3L34-ENGL 2000 iei 1624669 0874515 225 D Page 5 EN 131 34:2000 I Scope This European Standard specifies general rules (test procedures, tes
10、t pieces) for the specification and approval of brazing procedures for all materials, metallic and non-metallic. It is anticipated that, where necessary, specific requirements for individual industries will be developed within this framework and detailed in the relevant application standard. The rec
11、ommended format for the procedure approval certificate is given in annex B. It assumes that the brazing procedure specifications are used in production and, in the case of manual flame brazing, by competent brazers approved in accordance with EN 13133, where relevant. 2 Normative references This Eur
12、opean Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publication
13、s apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). EN 13133 Brazing - Brazer approval. EN 12797 Brazing - Destructive examination of brazed joints. EN 12799
14、Brazing - Non-destructive testing of brazed joints. 3 Terms and definitions For the purposes of this European Standard the following terms and definitions apply. 3.1 brazer person who performs the brazing in a manual operation; he guides the heating means and ensures the introduction of the brazing
15、filler metal 3.2 brazing procedure specification (BPS) document providing the designations or values of the required variables necessary to achieve consistent brazing for the defined application NOTE An example of the format to be used is given in annex C. O BSI 10-2000 STD=BSI BS EN 13L34-ENGL 2000
16、 Lb24bb 08745Lb Lb1 m Page 6 EN 131 34:2000 3.3 brazing procedure test making and testing of a brazed joint in order to prove the feasibility of a brazing procedure 3.4 manufacturer person or organization responsible for the manufacture of the brazed joints 3.5 examiner or examining body person or o
17、rganization appointed to verify compliance with the applicable standard NOTE The examiner or examining body may be a notified body or recognized third-party, if required. 3.6 preliminary brazing procedure specification (pBPS) tentative BPS, which is assumed to be adequate by the manufacturer, but wh
18、ich has not been approved. Brazing of test pieces needed for the approval of a BPS has to be carried out on the basis of a pBPS 3.7 test piece assembly which is brazed together during the approval test 3.8 test specimen sample taken from a test piece 4 Information and requirements to be agreed and t
19、o be documented The following information and requirements shall be agreed and documented prior to the contract. a) b) c) d) e) 9 9) The application standards to be used, if any, together with any supplementary requirements (see clause 1). The specification of the parent materials. The types of test
20、, if any, to be carried out on brazing consumables. The brazing process to be used. The brazing filler metal and flux (if any) to be used, if not specified elsewhere. The relevant brazing variables (see clause 5 and annex A). The pBPS, based on the information detailed in this clause (see clause 6).
21、 0 BSI 10-2000 Page 7 EN 131 34:2000 h) i) j) The jointassembly design if it is not specified in the relevant application standard (see 8.1). The number of test pieces, the number of test specimens and the number of further test specimens for re-testing (see 8.2, 8.3 and 9.5). The extent of visual t
22、esting, the details of metallographic examination and additional testing requirements for non-destructive and destructive tests (see clause 9). The acceptancehon-acceptance criteria, including (where appropriate) the level of confidence (see 9.5 and annex A). The range of approval, where this is pos
23、sible (see clause IO). k) 1) m) Records and documentation. NOTE Examples of the formats to be used are given in annexes BI C and D. 5 Brazing variables The relevant brazing variables shall be selected see 4 9 and annex A. 6 pBPS A pBPS shall be prepared which it is believed will meet the requirement
24、s for the brazed assemblies see 4 g). This shall be approved by one of the methods given in clause 7 to become an approved BPS (see 3.2). 7 Approval of BPS A BPS can be suitably approved in one of three ways: a) by submitting documentary evidence to verify that a relevant procedure that has been pro
25、ven by experience is available for approval by an examiner or examining body; by submitting a relevant procedure previously accepted by another examiner or examining body; by carrying out appropriate brazing procedure tests for approval by an examiner or examining body. b) c) In the case of manual h
26、and torch (flame) brazing, the brazer who undertakes the brazing procedure test satisfactorily in accordance with this standard is thereby approved by EN 13133. O BSI 10-2000 Page 8 EN 131 34:2000 8 Test pieces and test specimens 8.1 General The pBPS shall be used to braze assemblies from which the
27、test specimens required for non-destructive and/or destructive tests can be taken. In a few cases, it may be possible to braze standard test pieces for this purpose but it will be more usual to braze a production assembly or to devise an assembly which simulates fairly closely the relevant part of t
28、he production assembly which will ultimately be required see 4 h). It will be necessary to simulate such items as the heat sink, restraint (particularly if the production assembly is to be jigged), and positioning of inserts. 8.2 Number of test pieces The number of test pieces shall be sufficient to
29、 allow the test specimens required for the non-destructive and/or destructive tests to be taken see 4 i) and clause 91. 8.3 Number of test specimens For a brazing procedure to be approved, the test pieces representing the brazing procedure test shall comply with the requirements necessary to produce
30、 test specimens for the non-destructive and destructive tests see c4 i) and clause 91. For the destructive tests detailed in 9.4 items I), 2), 4) and 5), a minimum of three test specimens is recommended. 9 Examination and testing 9.1 Extent of testing Tests which may be suitable are described in EN
31、12797 and EN 12799 but in many cases it will be found that very few, if any, of them are suitable for the assemblies in question. For example, if a component is required to maintain a very low internal pressure, then a vacuum leak test is the meaningful test, destructive tests giving no useful infor
32、mation. When none of the tests given in EN 12797 and EN 12799 are relevant, suitable tests shall be devised see 4 j). For example, if an assembly is exposed to high stress at elevated temperature, then some type of stress rupture test may be required. 9.2 Visual examination All joints shall be visua
33、lly examined see 4 j) in accordance with EN 12799; the brazed assembly may need to be cut open to offer an internal examination and the test may therefore be destructive. Q BSI 10-2000 STD-BSI BS EN L3L3Y-ENGL 2000 m Lb24bb9 0834519 770 m Page 9 EN 131 34:2000 9.3 Metallographic examination All join
34、ts shall be metallographically examined see 4 j) in accordance with EN 12797. 9.4 Additional examination and testing The basic requirement is to examine the soundness of the brazed assembly. When any of the following additional non-destructive tests are specified see 4 j) they shall be carried out a
35、s described in EN 12799: a) ultrasonic examination; b) radiographic examination; c) penetrant testing; d) leak testing; e) proof testing ; 9 thermographic examination. When any of the following additional cdstructive tests are spec shall be carried out as described in EN 12797: Fied see 4 j) they 1)
36、 shear tests; 2) tensile tests: 3) hardness tests; 4) peel tests; 5) bend tests. No modification shall be made to the test specimens that will affect the quality of the results obtained from destructive and non-destructive test, and no repair or modification to the procedures shall be carried out on
37、 a test specimen at any stage in its manufacture. Procedures such as surface dressing shall be allowed for non-destructive tests where non-critical surface imperfections affect the result of the test. 9.5 Re-testing If the test specimen fails to comply with the specified acceptance criteria see 4 k)
38、 for the agreed tests, the specified number of further tests specimens see 4 i) shall be prepared for each one that failed, either from the same brazed assembly or from a newly brazed assembly. These shall be subjected to the same test. If any of these additional test specimens do not comply with th
39、e specified acceptance criteria, the brazing procedure shall be regarded as not capable of complying with the requirements of this standard without modification. O BSI 10-2000 Page 10 EN 131 34:2000 IO Range of approval An approval of a BPS is valid for brazing in workshops or sites under the same t
40、echnical and quality control of that manufacturer. To avoid duplication of nearly technically identical procedure tests (see annex A), it may be possible to establish ranges for approval of, for example, parent materials, filler materials, thicknesses, diameters or lap lengths, based on previous doc
41、umentary evidence see 4 I). I1 Brazing procedure approval record (BPAR) The BPAR is a statement of the results of assessing each test piece including retests. The record shall include details of any test failures. If no non-compliant features or test results are found, a statement that the test samp
42、les made by the brazing procedure satisfy the agreed criteria in respect of that type of sample and the tests conducted shall be signed by the examiner or examining bodys representative. It is recommended that the form given in annex C is used to record or refer to details of the approval test of br
43、azing procedure and the form given in annex D is used to record details of the results of such a test. Q BSI 10-2000 STDeBSI BS EN 13334-ENGL 2000 H 1624669 0874523 529 Page 11 EN 131 34:2000 Annex A (informative) Guidelines for practical application of brazing procedure approval Before any brazing
44、procedure approval is undertaken, there is a crucial need to examine all the relevant factors, if only to avoid subsequent unnecessary expense. Although not specifically within the scope of this standard, this examination should also cover the requirements for inspection of production assemblies, in
45、cluding the acceptance criteria. It is important to recognize that the procedure approval test is not intended to be a guide to production reproducibility. Table A.l lists the relevant brazing variables for the common brazing processes. It is not exhaustive and for some specific applications it may
46、be necessary to include others but it does address the majority of cases. It is essential to recognize the importance of carrying out realistic tests for brazing procedure approval. In such cases it is unnecessarily expensive to carry out unsuitable tests and possibly dangerously misleading. This ap
47、plies equally to the choice of tests with which to prove the procedure and the types of test piece used. The tests to prove the procedure have to be selected to take into account the requirements in service, e.g. if the brazed assembly needs to hold a high internal vacuum, then the approval testing
48、has to include a vacuum leak test at the appropriate level. Other types of test may be deemed relevant, depending on the service conditions, but the primary requirements have always to be borne in mind and given priority. The choice of test piece, e.g. form and size, has an importance in brazing tha
49、t it seldom has in welding. As an example of this, in general terms, welded specimens beyond a certain minimum size have similar properties and for this reason a given welding procedure can be used for a range of different joints. In general this is not true of brazed components. The extreme example of this is where dissimilar materials with significantly different coefficients of thermal expansion are being joined; small pieces can be brazed without much difficulty but the differential expansion/contraction prevents big ones from being joined. Even with simi
