BS EN 14728-2005 Imperfections in thermoplastic welds - Classification《热塑焊接中的缺陷 分类》.pdf

1、BRITISH STANDARDBS EN 14728:2005Imperfections in thermoplastic welds ClassificationThe European Standard EN 14728:2005 has the status of a British StandardICS 25.160.40g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g

2、53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 14728:2005This British Standard was published under the authority of the Standards Policy and Strategy Committee on 7 December 2005 BSI 7 December 2005ISBN 0 580 46108 4National forewordThis British Standard is the official En

3、glish language version of EN 14728:2005.The UK participation in its preparation was entrusted to Technical Committee PRI/80, Welding of plastics, which has the responsibility to:A list of organizations represented on this committee can be obtained on request to its secretary.Cross-referencesThe Brit

4、ish Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Onl

5、ine.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsibl

6、e international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK.Summary of pagesThis document comprises a front cover, an inside front cover, the

7、 EN title page, pages 2 to 14, an inside back cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14728May 2005ICS 25.160.40En

8、glish versionImperfections in thermoplastic welds - ClassificationDfauts dans les assemblages souds enthermoplastiques - ClassificationUnregelmigkeiten an Schweiverbindungen vonthermoplastischen Kunststoffen - EinteilungThis European Standard was approved by CEN on 21 March 2005.CEN members are boun

9、d to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Cent

10、ral Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as th

11、e officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sw

12、eden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2005 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Re

13、f. No. EN 14728:2005: EEN 14728:2005 (E) 2Contents Page Foreword3 1 Scope 42 Normative references 43 Symbols and designations .54 Definition and classification of imperfections5 Annex A (normative) Explanations for characters 3, 4 and 5 according to CEN ISO/TS 1784512 Bibliography 14EN 14728:2005 (E

14、)3Foreword This document (EN 14728:2005) has been prepared by Technical Committee CEN/TC 249 “Plastics”, the secretariat of which is held by IBN/BIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest b

15、y November 2005, and conflicting national standards shall be withdrawn at the latest by November 2005. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Rep

16、ublic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 14728:2005 (E) 41 Scope This document specifies a classifica

17、tion and a description of imperfections likely to be encountered in thermoplastic welded joints. This document applies to the following welding processes: heated tool welding; electrofusion welding; hot gas welding; extrusion welding. This document applies to the following group of materials: PVC-C;

18、 PVC-U including PVC-NI, PVC-RI, PVC-HI; PP including PP-B, PP-H, PP-R; PE; PVDF; ECTFE; FEP; PFA. This document is not concerned with the search for the possible influence of these defects on the behaviour of joints in relation to the different types of stress to which the latter may be subjected o

19、r on method for preventing such defects. It cannot therefore be used for the acceptance of welds which is defined in quality level standards (see 1). Only defects giving rise to discontinuities of materials or changes in shape are taken into consideration in this document, specifying their type, the

20、ir shape and their positions, without however always indicating their origin or their causes. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edi

21、tion of the referenced document (including any amendments) applies. CEN ISO/TS 17845, Welding and allied processes Designation system for imperfections (ISO/TS 17845:2004) EN 14728:2005 (E)53 Symbols and designations The abbreviations used for thermoplastic materials are listed in Table 1. Table 1 A

22、bbreviations used for thermoplastic materials Abbreviation Thermoplastic material PVC-C Polyvinyl chloride chlorinated PVC-U Polyvinyl chloride unplasticized PVC-NI Polyvinyl chloride normal impact PVC-RI Polyvinyl chloride raised impact PVC-HI Polyvinyl chloride high-impact PP-B Polypropylene block

23、 copolymer PP-H Polypropylene homopolymer PP-R Polypropylene random copolymer PE Polyethylene PVDF Polyvinylidene fluoride ECTFE Ethylene chlorotrifluoroethylene FEP Fluorinated ethylene propylene PFA Perfluoroalkoxy 4 Definition and classification of imperfections The numbering system used for the

24、classification of imperfections shall be as defined in CEN ISO/TS 17845. The classification of imperfections for thermoplastic materials is given in Table 2. Explanations for characters 3, 4 and 5 are given in Annex A. EN 14728:2005 (E) 6Table 2 Imperfections in thermoplastic welds Numbers Designati

25、ons Descriptions Illustrations 1AAAA Cracks Break in continuity of the material 1AAAK Crack at bead start/stop position Crack between the start and stop positions of a welding run 1AAJA Group of disconnected cracks Set of grouped cracks of any orientation 1ABAA Longitudinal crack Crack whose main di

26、rection is close to that of the axis of the weld 1ACAA Transverse crack Crack whose direction is more or less perpendicular to the axis of the weld 1AFAA Branching crack Set of interconnected cracks in the form of arborescence (to be continued)EN 14728:2005 (E)7Table 2 (continued)Numbers Designation

27、s Descriptions Illustrations 2AAAA Cavity Open or closed cell 2BAAA Gas cavity Cavity formed by evolution or entrapment of gas(es) This cavity is distinguishable by having a similar colour as the surrounding material. It could be: 2BGAA Spherical 2BJAA Elongated 2BEAB Tubular (wormhole) 2BAFA Cluste

28、red porosity Group of gas cavities 2BGGB Uniformly distributed porosity Spheroidal gas cavities regularly distributed in the weld 2BAMF Surface pore Small gas cavities opening out on the surface 2BIHB Linear porosity Gas cavities distributed along a line parallel to the axis of the weld (to be conti

29、nued)EN 14728:2005 (E) 8Table 2 (continued)Numbers Designations Descriptions Illustrations 2CAAA Shrinkage cavity Cavity due to shrinkage of weld during solidification This cavity may be distinguishable by evidence of ductility or stress whitening 2DAAA Craze Crack-like regions of micro cavitated ma

30、terial, caused by stress and/or chemicals, producing a local whitening of the material No need for figure 3AAAA Inclusion Foreign material trapped in the weld 3JAAA Parent material inclusion Fragment of parent material trapped in the weld (e.g. shaving) 3KAAA Degraded polymer Inclusion of decomposit

31、ion products 4BAAA Lack of fusion Cold weld For socket and electrofusion, incomplete fusion around the circumference of joint 4CAAG Incomplete penetration For hot gas welding and extrusion welding the penetration of the weld material into the joint is less than the specified value (to be continued)E

32、N 14728:2005 (E)9Table 2 (continued)Numbers Designations Descriptions Illustrations 4DAAG Excessive penetration Excess of material at the root of a weld 4EAAF Undercut Lack of material on the edges of the weld 4QBAF Groove in upset or reinforcement Excessive groove depth in the bead or in the weld 4

33、QCJB Groove in upset or reinforcement Transverse groove in weld bead at the weld line of an injection moulded component No need for figure 4RAAA Compressed pipe ends Over penetration of pipe into sockets 4SAAA Insufficient penetration For electrofusion welding and socket welding insufficient penetra

34、tion of the pipe(s) into the socket 4TAAA Displaced filament Excessive movement of filament during fusion welding cycle 4UAAA Failure of welding indicator No need for figure (to be continued)EN 14728:2005 (E) 10Table 2 (continued)Numbers Designations Descriptions Illustrations 5AAAA Imperfect shape

35、Deviation from the specified geometry of the weld No need for figure 5DAAA Overlap Excess of weld which spreads over the surface of the base material, without bonding to it 5EJAA Linear misalignment Deviation from specified tolerances in coplanarity between two welded pieces 5EKAA Angular misalignme

36、nt Deviation from specified angle between two welded pieces 5GAAA Irregular width Excessive variation in weld or bead width 5HAAA Irregular surface Excessive variation in surface of weld (roughness, corrugation) 6AAAA Imperfect weld dimensions Deviation from specified dimensions of weld No need for

37、figure 6BAAA Excess weld material (to be continued)EN 14728:2005 (E)11Table 2 (end)Numbers Designations Descriptions Illustrations 6EAAA Excessive upset Excessive weld bead dimension 6FAAA Incompletely filled groove Local or continuous deficiency of weld material 6HAAA Excessive asymmetry of welds A

38、symmetric weld bead; asymmetric angle weld7BAAA Thermal damage outside weld area Surface alteration resulting from the accidental action of a source of heat No need for figure 7GAAA Poor restart Local irregularity in surface at location of a restart No need for figure 7TAAA Weld intersections Inters

39、ections of weld runs for hot gas or extrusion welding 8TCGF Transverse ripple Excessive surface ripple (waves) in extrusion welding No need for figure 9AAAA Mechanical damage Local damage No need for figure 9CAAA Tool mark Local damage due to a tool No need for figure EN 14728:2005 (E) 12Annex A(nor

40、mative)Explanations for characters 3, 4 and 5 according to CEN ISO/TS 17845 Character 3 given in Table A.1 defines the shape of individual imperfections. Table A.1 Definition of the third character Character Shape of individual imperfections A Undefined shape B Longitudinal (x axis) C Transverse (y

41、axis) D In thickness (z axis) E Tubular or wormhole F Branching G Spherical H Radiating (star) I Elongated or linear J Angular KCharacter 4 given in Table A.2 defines the morphology of groups of imperfections. Table A.2 Definition of the fourth character Character Morphology of groups of imperfectio

42、ns A Undefined B Local (confined in a particular space of the testing area)C Intermittent D Local intermittent E Continuous F Clustered G Uniformly distributed H Aligned (linear distributed) I Disconnected J Isolated (only one imperfection over the whole testing area)K Irregular L Opened M Local clu

43、stered NEN 14728:2005 (E)13Character 5 given in Table A.3 defines the location of the imperfections. Table A.3 Definition of the fifth character Character Location of imperfections A Undefined location B Weld metal / Weld polymer / Nugget / Braze metal C Weld junction / Weld toe / Edge of nugget / B

44、razed junction (including diffusion zone) D HAZ E Unaffected parent material F Weld face / Top cut edge G Weld root / Bottom cut edge H Side wall / Cut face I Joining plane J Inter-run K Crater/bead stop L Tack weld M Foil N Kerf OEN 14728:2005 (E) 14Bibliography 1 WI00249492, Geometric imperfection

45、s in thermoplastic welds Quality levels blankBS EN 14728:2005BSI389 Chiswick High RoadLondonW4 4ALBSI British Standards InstitutionBSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is in

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