1、BS ISO 18211:2016Non-destructive testing Long-range inspection ofabove-ground pipelines andplant piping using guidedwave testing with axialpropagationBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 18211:2016 BRITISH STANDARDNational forewordThis British Stand
2、ard is the UK implementation of ISO 18211:2016.During the development of this standard, the UK Committee voted against its approval as an International Standard. The UK Committee is of the opinion that the National Standard BS 9690 has a more detailed approach to the subject, including the requireme
3、nt for information to be provided by the client (e.g. plant owner) to the inspector.The UK Committee is of the opinion that there could be more information about data quality and interpretation in ISO 18211 and that the test procedure could detail engagement with the client to ensure appropriate dep
4、loyment.BS 9690 has been developed for a wide audience with the intention that interested parties such as plant operators can use the BS standard as performance criteria when issuing Guided wave testing (GWT) contracts. GWT is different from all other methods of Nondestructive testing (NDT) includin
5、g Ultrasonic testing, and BS 9690 has been developed to highlight and explain many new concepts and requirements which are associated with it.The UK participation in its preparation was entrusted to Technical Committee WEE/46, Non-destructive testing.A list of organizations represented on this commi
6、ttee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2016. Published by BSI Standards Limited 2016ISBN 978 0 580 86395 0ICS 19.100
7、Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2016.Amendments/corrigenda issued since publicationDate Text affectedBS ISO 18211:2016 ISO 2016Non-des
8、tructive testing Long-range inspection of above-ground pipelines and plant piping using guided wave testing with axial propagationEssais non destructifs Vrification large chelle des rseaux de canalisations hors sol et de la tuyauterie dusine utilisant un essai donde guide propagation axialeINTERNATI
9、ONAL STANDARDISO18211First edition2016-07-15Reference numberISO 18211:2016(E)BS ISO 18211:2016ISO 18211:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced
10、or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO c
11、opyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 18211:2016ISO 18211:2016(E)Foreword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Test personnel . 35 General 36 Factors influen
12、cing GWT performance . 46.1 External diameter . 46.2 Pipeline geometry 46.3 Test range 46.4 Road crossing . 57 Test equipment. 57.1 General . 57.2 Probe ring 57.3 Signal processing and analysis system . 57.4 Periodic verification of equipment performance 57.5 Instrument settings . 68 Test procedure
13、69 Requirements for test data quality . 610 Testing . 710.1 Preparation of the test object . 710.1.1 Surface temperature . 710.1.2 Removal of insulation 710.1.3 Wall thickness assessment 710.1.4 Surface preparation . 710.2 Probe ring test position . 810.3 Data collection . 810.4 Reporting sensitivit
14、y 810.5 Data interpretation 810.6 Detection sensitivity . 910.7 Visual confirmation . 911 Complementary NDT to support the GWT . 912 Test report . 9Annex A (informative) Selection of guided wave modes .11Bibliography .15 ISO 2016 All rights reserved iiiContents PageBS ISO 18211:2016ISO 18211:2016(E)
15、ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a te
16、chnical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters
17、of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This documen
18、t was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such
19、patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does n
20、ot constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.
21、org/iso/foreword.html.The committee responsible for this document is IIW, International Institute of Welding, Commission V.Requests for official interpretations of any aspect of this International Standard should be directed to the ISO Central Secretariat, who will forward them to the IIW Secretaria
22、t for an official response.iv ISO 2016 All rights reservedBS ISO 18211:2016INTERNATIONAL STANDARD ISO 18211:2016(E)Non-destructive testing Long-range inspection of above-ground pipelines and plant piping using guided wave testing with axial propagation1 ScopeThis International Standard specifies a m
23、ethod for long-range testing of carbon and low-alloy steel above-ground pipelines and plant piping using guided ultrasonic waves with axial propagation applied on the entire circumferential pipe section, in order to detect corrosion or erosion damage.The guided wave testing (GWT) method allows for f
24、ast inspection of above-ground pipelines, plant piping and cased road crossings, giving a qualitative screening and localization of probable corroded and eroded areas. GWT is typically performed on operating piping systems.This International Standard is applicable to the following types of pipes:a)
25、above-ground painted pipelines;b) above-ground insulated pipelines;c) painted plant piping;d) insulated plant piping.NOTE Pipe sections within road crossings with external casings (without bitumen or plastic coating) are a special case of buried pipe where there is no soil pressure on the OD of the
26、pipe. This International Standard applies to these cased road crossings.Other types of pipes not included in the above list need dedicated approaches due to increased complexity.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are in
27、dispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 9712, Non-destructive testing Qualification and certification of NDT personnel3 Terms and definitionsFor
28、 the purposes of this document, the following terms and definitions apply.3.1axial directiondirection along the main axis of the pipe3.2circumferential directiondirection around the circumference of the pipe3.3total pipe wall cross-sectionTCSarea between the inner and outer diameters of the pipe in
29、a plane perpendicular to the pipe axis ISO 2016 All rights reserved 1BS ISO 18211:2016ISO 18211:2016(E)3.4cross-section changeequivalent cross-section change calculated assuming that an indication is purely caused by a change in the cross-section of the pipe wall3.5datum pointreference point for rep
30、orting a test position (3.16) and for correlating test results with the corresponding position on the test object3.6dead zonelength of pipe on either side of the test position (3.16) where reflectors of interest cannot be detected because they are covered by the transmitted pulse3.7flexural modenon-
31、symmetric bending type mode of guided wave propagation in pipes, with particle displacements in axial, circumferential and radial directions3.8focusconcentration of guided waves at a single axial and circumferential position, achieved either by hardware settings or by post-processing of a recorded s
32、et of signals (synthetic focus)3.9geometric featurepipeline feature (e.g. weld, support, flange, bend, etc.) causing the reflection of guided waves because of a cross-section change (3.4) or other acoustic impedance variation3.10guided wave modedistinct type of guided wave with a specific vibration
33、pattern3.11longitudinal modesymmetric compression type mode of guided wave propagation in pipes, with particle displacements predominantly in the axial direction (3.1)3.12primary modeguided wave mode (3.10) which is chosen for the incident wave3.13probe ringcircumferential component, containing tran
34、sducer elements with direct contact to the pipe3.14secondary modeguided wave mode (3.10) which is different from the primary mode (3.12) and is generated by mode conversion at pipe features or discontinuities3.15test frequencycentre frequency of the pulses transmitted by the probe ring (3.13)3.16tes
35、t positionaxial position on the pipe where the probe ring (3.13) is placed2 ISO 2016 All rights reservedBS ISO 18211:2016ISO 18211:2016(E)3.17test rangedistance between the test position (3.16) and the furthest position for which the minimum acceptable sensitivity of the reference signal is achieved
36、, in each direction (positive or negative)3.18torsional modesymmetric twisting type mode of guided wave propagation in pipes, with particle displacements in the circumferential direction (3.2)4 Test personnelThe personnel performing ultrasonic guided wave testing shall be qualified in accordance wit
37、h ISO 9712 or with any another equivalent standard of the relevant industrial sector.Training in the use of the specific equipment is required because there are significant differences between the available systems and diagnostic approaches.5 GeneralUltrasonic guided wave testing (GWT) uses elastic
38、waves which are guided along the pipe wall and can travel long distances, thus providing rapid near complete coverage of the volume of the pipe wall.The typical test setup is comparable to conventional ultrasonic pulse-echo testing: an ultrasonic instrument forces transducers in the probe ring to ge
39、nerate ultrasonic waves in the pipe wall which are reflected by discontinuities and received by the same probe ring. The time-of-flight of the received signal indicates the distance between the discontinuities and the probe ring. A single test with guided waves can cover a length of pipe of tens of
40、meters.Within this International Standard, GWT is performed as a screening method. The reflections returning from discontinuities and received by the ultrasonic instrument indicate the position of the discontinuity. However, they do not give detailed quantitative information about its morphology. Th
41、erefore, GWT is used to indicate any locations which need to be followed up with complementary detailed inspection. More information on the nature of guided waves is given in Annex A.Within this International Standard, GWT typically uses a frequency range between 20 kHz and 500 kHz. If the performan
42、ce of the test has been shown to have equal or better sensitivity to that obtained with the frequency range specified above, a frequency lower than 20 kHz can be used for GWT.The successful application of guided ultrasonic waves requires the following:a) selective pure mode transmission and receptio
43、n;b) wave modes which are non-dispersive in the frequency range used;c) coverage of the full cross section of the pipe wall;d) signals coming from each direction shall be distinguished.The amplitude of a reflected ultrasonic guided wave signal from a discontinuity varies in a complex manner that dep
44、ends on many factors such as test frequency, guided wave mode and the specific morphology of the discontinuity. It is often possible to correlate the size of the reflected signal with the overall cross-section change in the pipe wall resulting from wall loss, meaning that GWT can qualitatively group
45、 discontinuities into different severity groups such as indications of low, medium and high concern. However, usually the parameter of interest when testing piping systems with wall loss is the remaining wall thickness in areas with discontinuities, which GWT cannot accurately provide (see Annex A f
46、or more information).It is recommended to perform ultrasonic guided wave testing using a range of frequencies to improve the accuracy of the test. Also, GWT ultrasonic instruments often employ advanced approaches like ISO 2016 All rights reserved 3BS ISO 18211:2016ISO 18211:2016(E)focusing or synthe
47、tic focusing to improve the sensitivity and discontinuity sizing ability of GWT. The use of these is not specified in this International Standard, but background information is provided in Annex A.6 Factors influencing GWT performance6.1 External diameterThe sensitivity of GWT depends on the cross-s
48、ection change. The absolute cross-section change in a pipe due to corrosion or erosion loss is measured in the units of area and depends on both the depth and the circumferential extent of the discontinuity. GWT is sensitive to a minimum per cent of cross-sectional loss, which is a function of both
49、the absolute cross-section change and the pipe geometry. As an example, a discontinuity in a small diameter pipe may represent a large per cent change in cross section that is easily detectable using GWT, but the same discontinuity in a large diameter pipe may represent a small cross-section change that cannot be detected using GWT. Because of this effective decrease in sensitivity as pipe diameter increases, testing of pipes larger than DN 600 (24 inches in diameter) can miss significant isolated corrosion pits, so it is recommended that comp
