BS EN 13100-4-2012 Non destructive testing of welded joints of thermoplastics semifinished products High voltage testing《热塑性半成品焊接接头的无损检验 高压检验》.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationNon destructive testing of welded joints of thermoplastics semifinished productsPart 4: High voltage testingBS EN 13100-4:2012National forewordThis British Standard is the UK imp

2、lementation of EN 13100-4:2012.The UK participation in its preparation was entrusted to Technical CommitteePRI/80, Welding thermoplastics.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary p

3、rovisions of a contract. Users are responsible for its correct application. The British Standards Institution 2012.Published by BSI Standards Limited 2012 ISBN 978 0 580 74082 4 ICS 25.160.40Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was pu

4、blished under the authority of the Standards Policy and Strategy Committee on 30 November 2012.Amendments issued since publicationDate Text affectedBRITISH STANDARDBS EN 13100-4:2012EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13100-4 October 2012 ICS 25.160.40 English Version Non destructiv

5、e testing of welded joints of thermoplastics semifinished products - Part 4: High voltage testing Essais non destructifs des assemblages souds sur produits semi-finis en thermoplastiques - Partie 4 : Essais haute tension Zerstrungsfreie Prfung von Schweiverbindungen thermoplastischer Kunstoffe - Tei

6、l 4: Hochspannungsprfung This European Standard was approved by CEN on 22 September 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date li

7、sts and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation unde

8、r the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Y

9、ugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EURO

10、PEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13100-4:2012: EBS EN 13100-4:2012EN 13100-4:2012 (E) 2 Contents Page Fore

11、word . 31 Scope . 42 Terms and definitions . 43 Symbols and designations 44 Principle of the test . 45 Equipment types . 55.1 General . 55.2 High frequency spark tester 55.3 DC Holiday detector 55.4 Pulsed Holiday detector . 66 Determination of test voltage 66.1 General . 66.2 Butt joints 66.3 Overl

12、ap joints 77 Test electrode 88 Test procedure 88.1 DC and pulsed holiday detectors 88.2 High frequency spark testers 99 Test report . 9BS EN 13100-4:2012EN 13100-4:2012 (E) 3 Foreword This document (EN 13100-4:2012) has been prepared by Technical Committee CEN/TC 249 “Platics”, the secretariat of wh

13、ich is held by NBN. 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 by April 2013, and conflicting national standards shall be withdrawn at the latest by April 2013. Attention is drawn to the possibi

14、lity that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document is composed of the following parts: EN 13100-1, Non destructive testing of welded joints of thermoplastic

15、s semi-finished products Part 1: Visual examination; EN 13100-2, Non-destructive testing of welded joints in thermoplastics semi-finished products Part 2: X-ray radiographic testing; EN 13100-3, Non destructive testing of welded joints in thermoplastics semi-finished products Part 3: Ultrasonic test

16、ing; EN 13100-4, Non destructive testing of welded joints of thermoplastics semifinished products Part 4: High voltage testing. According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, B

17、elgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Swi

18、tzerland, Turkey and the United Kingdom. BS EN 13100-4:2012EN 13100-4:2012 (E) 4 1 Scope This European Standard specifies the equipment and methods for the high voltage testing of butt or overlap welded joints in thermoplastic sheets for locating through-thickness defects only. It applies to new unu

19、sed constructions only. 2 Terms and definitions For the purpose of this document, the following terms and definitions apply. 2.1 dielectric strength maximum voltage a material of unit thickness can withstand continuously without failure 3 Symbols and designations Symbols and designations are given i

20、n Table 1. Table 1 Symbols and designations Symbol Designation Unit DsDielectric strength Vmm-1VBBreakdown voltage V dtDistance from test electrode to conductor mm VIInitial test voltage V VAActual voltage used for the test V VoVoltage which causes a spark at a hole in the plastic sheet V 4 Principl

21、e of the test A high voltage is applied to one side of the joint to be tested using a suitable electrode, the other side of the material needs to be in contact with a conductive substrate which in some cases will need a connection back to the test equipment. The test shall be carried out with a volt

22、age high enough to jump the gap between the test electrode and a conductor. A defect is indicated by a spark discharge and, depending on the equipment used, a simultaneous optical and / or acoustic signal. The health and safety aspects (e.g. electric shocks, risks of explosions in flammable atmosphe

23、re) together with the environmental impacts (e.g. electromagnetic disturbances) shall be thoroughly considered before operating the equipment. NOTE Moisture in concrete can make it sufficiently conductive to allow high voltage testing to be used. BS EN 13100-4:2012EN 13100-4:2012 (E) 5 5 Equipment t

24、ypes 5.1 General There are three types of high voltage tester available. The most appropriate type to be used will depend on the type of tests to be carried out and customer requirements. 5.2 High frequency spark tester 5.2.1 Principle This equipment generates a high frequency AC voltage of up to 10

25、0 kV. It is normally mains powered. The output is low power and normally un-stabilised. The output voltage is adjusted by spark length. Defects are normally indicated by visual spark only. 5.2.2 Advantages No connection to the substrate required as long as it is metal and has an area 1 000 times lar

26、ger than the test electrode. Higher output voltages, allowing thicker material or longer overlap joints to be tested. 5.2.3 Limitations No output voltage meter. Fault identified by visual spark only. AC mains powered. 5.3 DC Holiday detector 5.3.1 Principle This equipment generates a DC high voltage

27、 of up to 50 kV. It can be mains or battery powered. The output is low power and normally stabilised. The output voltage is indicated on a meter either in the unit or external to it. Defects are indicated by the activation of an optical and/or acoustic signal as well as a visual spark. 5.3.2 Advanta

28、ges The test voltage can be set accurately. Can be used on concrete substrates. 5.3.3 Limitations Connection to substrate required. Can be affected by moisture on the surface of the thermoplastic sheet. BS EN 13100-4:2012EN 13100-4:2012 (E) 6 5.4 Pulsed Holiday detector 5.4.1 Principle This equipmen

29、t generates a pulsed DC high voltage of up to 50 kV. The pulse rate can be from 30 to 10 000 pulses per second depending on the manufacturer. Pulsed units tend to have higher power output than spark testers or DC holiday detectors. The output voltage can be verified using a crest reading voltmeter.

30、Imperfections are indicated by the activation of an optical and/or acoustic signal as well as a visual spark. 5.4.2 Advantages Can work in the presence of a small amount of moisture on the surface. 5.4.3 Limitations Connection to substrate required. Output voltage harder to verify (special meter req

31、uired). Lower speed of testing dependent on pulse rate. 6 Determination of test voltage 6.1 General This section is for testers that can be set to a known voltage. 6.2 Butt joints 6.2.1 Test arrangement For butt joints in thermoplastic sheets with a thickness in the range 1 mm to 30 mm (see Figure 1

32、), the initial test voltage, VI, is given by: VI= 250 (1000 dt) (1) Providing the test electrode is in contact with the upper surface of the sheet and the conductive substrate is in contact with the lower surface of the sheet, dtis equal to the sheet thickness. BS EN 13100-4:2012EN 13100-4:2012 (E)

33、7 Key a substrate b plastic sheet c weld d electrode Figure 1 Butt joint However, depending on the dielectric strength of the sheet, VIcan damage the material. The breakdown voltage, VB, is given by: VB= Dsdt(2) The value of the breakdown voltage, VB, for each sheet shall be calculated from Formula

34、(2) using the value of Dsprovided by the sheet manufacturer. If VIVB, then experimental trials, as described in 6.2.2, shall be carried out to determine VA. If the dielectric strength is not known, the output voltage of the tester shall be set to 1.3 VI. The test electrode shall then be placed on an

35、 unwelded test piece of the same material in which the welds are to be examined and the voltage shall be applied for a duration of 1 min. If no fault is made in the sheet then VAshall be equal to VI. If the material fails then further experimental trials, as described in 6.2.2, shall be carried out

36、to determine VA. 6.2.2 Determination of VAif VI VBA 1 mm diameter perpendicular hole shall be made in an unwelded test piece of the same material in which the welds are to be examined, using a clean drill. The minimum distance from the hole to the edge of the test piece shall be five times the sheet

37、 thickness. With the electrode over the hole, the voltage shall be increased until a spark jumps the gap. This voltage, Vo, shall be noted. Further holes shall be made in the test piece at an angle of 45. The minimum distance between holes and also between any hole and the edge of the test piece sha

38、ll again be five times the sheet thickness. The test voltage shall then be increased to (VB+Vo)/2 and, if all of the holes are detected, this shall be used as VA. If any of the holes are not detected, the test voltage shall be increased by 10 % and the tests shall be repeated using new holes. Test h

39、oles shall only be used once. 6.3 Overlap joints In overlap joints the distance from the test electrode to the substrate, dt, can be many times the thickness of the material and the test voltage required could therefore cause the material to break down. To minimise the test voltage required, a thin

40、un-insulated wire should be placed as close as possible to the inside of the weld. See Figure 2. BS EN 13100-4:2012EN 13100-4:2012 (E) 8 Key a electrode b plastic sheet c weld d wire Figure 2 Overlap joint If the required test voltage is higher than the dielectric strength for the given thickness, c

41、heck that the material can withstand the higher test voltage, place the test electrode on a sample piece of the material, not a weld and apply the test voltage for 1 min. If no fault is made in the sample then the test voltage is usable. If the material fails then the maximum distance from the test

42、electrode to the wire must be reduced either by reducing the width of the weld or by changing the material used, and the test voltage recalculated. 7 Test electrode The test electrode shall be constructed in such a way that it makes contact with the sheet surface without gapping or missing any of th

43、e area to be tested. For recessed or protruding areas, a small (i.e. with a contact area 1 cm2) brush electrode should be used. For overlap joints, a small brush or pointed electrode should be used. The test electrodes shall be kept in such a mechanical condition as to maintain contact with the shee

44、t surface at all times during the examination. 8 Test procedure 8.1 DC and pulsed holiday detectors The surface to be tested shall be clean and dry. The test electrode shall be connected to the high voltage tester in accordance with the manufacturers instructions. The high voltage return lead from t

45、he detector shall be connected to the substrate or wire and a separate electrical connection shall be made between the substrate and a true earth. The output voltage of the detector shall be adjusted to the required level, VA. To check that the detector is working, the test electrode shall be placed

46、 on the substrate; a spark should be seen and the audio / visual alarm should operate. The test electrode shall be moved without stopping along the weld and in contact with it, at a speed of 40 cm/s maximum, or slower if indicated by the detector manufacturer. The location of faults shall be visibly

47、 marked as they are detected. BS EN 13100-4:2012EN 13100-4:2012 (E) 9 All faults detected shall be repaired and the area retested. 8.2 High frequency spark testers The surface to be tested shall be clean and dry. The test electrode shall be connected to the spark tester in accordance with the manufa

48、cturers instructions. If possible, a separate electrical connection should be made between the substrate or wire and a true earth, since this will give a brighter spark. With the test electrode on the surface, the output of the spark tester shall be adjusted to give a spark length 3 mm longer than t

49、he maximum distance expected when testing between the electrode and substrate or wire. See Figure 3. Dimensions in millimetres Key a substrate b plastic sheet c wire d electrode Figure 3 Setting of spark testers output for: 1) overlap joint, and 2) butt joint For butt joints, the test electrode shall be placed on the sheet surface 3 mm from the edge and the output voltage of the spark tester shall be increased until a spark is seen jumping