1、BSI Standards PublicationBS EN 16407-2:2014Non-destructive testing Radiographic inspection ofcorrosion and deposits in pipesby X- and gamma raysPart 2: Double wall radiographic inspectionBS EN 16407-2:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 16407-2:
2、2014.The UK participation in its preparation was entrusted to TechnicalCommittee WEE/46, Non-destructive testing.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Us
3、ers are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 77931 2ICS 19.100; 23.040.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the autho
4、rity of theStandards Policy and Strategy Committee on 31 January 2014.Amendments issued since publicationDate Text affectedBS EN 16407-2:2014EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 16407-2 January 2014 ICS 19.100; 23.040.01 English Version Non-destructive testing - Radiographic inspecti
5、on of corrosion and deposits in pipes by X- and gamma rays - Part 2: Double wall radiographic inspection Essais non destructifs - Examen radiographique de la corrosion et des dpts dans les canalisations, par rayons X et rayons gamma - Partie 2: Examen radiographique double paroi Zerstrungsfreie Prfu
6、ng - Durchstrahlungsprfung auf Korrosion und Ablagerungen in Rohren mit Rntgen- und Gammastrahlen - Teil 2: Doppelwand Durchstrahlungsprfung This European Standard was approved by CEN on 26 October 2013. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the co
7、nditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists 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 exi
8、sts in three official versions (English, French, German). A version in any other language made by translation under 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 st
9、andards bodies of Austria, Belgium, 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,
10、Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means rese
11、rved worldwide for CEN national Members. Ref. No. EN 16407-2:2014 EBS EN 16407-2:2014EN 16407-2:2014 (E) 2 Contents Page Foreword 4 1 Scope 5 2 Normative references 5 3 Terms and definitions .6 4 Classification of radiographic techniques 8 5 General 9 5.1 Protection against ionizing radiation.9 5.2
12、Personnel qualification .9 5.3 Identification of radiographs 9 5.4 Marking .9 5.5 Overlap of films or digital images 9 5.6 Types and positions of image quality indicators (IQI) .9 5.6.1 Single wire IQI 9 5.6.2 Duplex wire IQI (digital radiographs) 10 6 Recommended techniques for making radiographs .
13、 10 6.1 Test arrangements 10 6.1.1 General . 10 6.1.2 Double wall single image (DWSI) 10 6.1.3 Double wall double image (DWDI) . 12 6.1.4 Alignment of beam and film/detector . 14 6.2 Choice of radiation source 14 6.3 Film systems and screens . 15 6.4 Screens and shielding for imaging plates (compute
14、d radiography only) 17 6.5 Reduction of scattered radiation . 18 6.5.1 Filters and collimators . 18 6.5.2 Interception of back scattered radiation 19 6.6 Source-to-detector distance 19 6.6.1 Double wall single image . 19 6.6.2 Double wall double image 20 6.7 Axial coverage and overlap . 20 6.8 Circu
15、mference coverage 21 6.8.1 General . 21 6.8.2 DWSI . 21 6.8.3 DWDI 22 6.9 Selection of digital radiographic equipment 22 6.9.1 General . 22 6.9.2 CR systems . 22 6.9.3 DDA systems . 22 7 Radiograph/digital image sensitivity, quality and evaluation 22 7.1 Minimum image quality values 22 7.1.1 Wire im
16、age quality indicators 22 7.1.2 Duplex wire IQIs (digital radiographs) 23 7.1.3 Minimum normalized signal to noise ratio (digital radiographs) . 23 7.2 Density of film radiographs . 23 7.3 Film processing 24 7.4 Film viewing conditions . 24 BS EN 16407-2:2014EN 16407-2:2014 (E) 3 8 Measurement of di
17、fferences in penetrated thickness . 24 8.1 Principle of technique . 24 8.2 Measurement of attenuation coefficient . 25 8.3 Source and detector positioning . 25 8.4 Image grey level profiles. 25 8.5 Validation 25 8.6 Key Points 25 9 Digital image recording, storage, processing and viewing 26 9.1 Scan
18、 and read out of image 26 9.2 Calibration of DDAs . 26 9.3 Bad pixel interpolation 26 9.4 Image processing 26 9.5 Digital image recording and storage . 26 9.6 Monitor viewing conditions 27 10 Test report 27 Annex A (normative) Minimum image quality values . 29 Annex B (informative) Penetrated thickn
19、ess measurements from image grey levels . 31 Annex C (normative) Determination of basic spatial resolution 33 Bibliography 36 BS EN 16407-2:2014EN 16407-2:2014 (E) 4 Foreword This document (EN 16407-2:2014) has been prepared by Technical Committee CEN/TC 138 “Non-destructive testing”, the secretaria
20、t of which is held by AFNOR. 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 July 2014, and conflicting national standards shall be withdrawn at the latest by July 2014. Attention is drawn to the
21、possibility 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. EN 16407 consists of the following parts, under the general title Non-destructive testing Radiographic inspectio
22、n of corrosion and deposits in pipes by X- and gamma rays: Part 1: Tangential radiographic inspection; Part 2: Double wall radiographic inspection. According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European
23、Standard: Austria, Belgium, 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
24、, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 16407-2:2014EN 16407-2:2014 (E) 5 1 Scope This European Standard specifies fundamental techniques of film and digital radiography with the object of enabling satisfactory and repeatable results to be obtained economically. The techni
25、ques are based on generally recognized practice and fundamental theory of the subject. This European Standard applies to the radiographic examination of pipes in metallic materials for service induced flaws such as corrosion pitting, generalized corrosion and erosion. Besides its conventional meanin
26、g, “pipe” as used in this standard should be understood to cover other cylindrical bodies such as tubes, penstocks, boiler drums and pressure vessels. Weld inspection for typical welding process induced flaws is not covered, but weld inspection is included for corrosion/erosion type flaws. The pipes
27、 may be insulated or not, and can be assessed where loss of material due, for example, to corrosion or erosion is suspected either internally or externally. This part of EN 16407 covers double wall inspection techniques for detection of wall loss, including double wall single image (DWSI) and double
28、 wall double image (DWDI). Note that the DWDI technique described in this part of EN 16407 is often combined with the tangential technique covered in EN 16407-1. This European Standard applies to in-service double wall radiographic inspection using industrial radiographic film techniques, computed d
29、igital radiography (CR) and digital detector arrays (DDA). 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the lat
30、est edition of the referenced document (including any amendments) applies. EN 14784-1, Non-destructive testing Industrial computed radiography with storage phosphor imaging plates Part 1: Classification of systems EN ISO 11699-1, Non-destructive testing Industrial radiographic films Part 1: Classifi
31、cation of film systems for industrial radiography (ISO 11699-1) EN ISO 11699-2, Non-destructive testing Industrial radiographic films Part 2: Control of film processing by means of reference values (ISO 11699-2) EN ISO 17636-2:2013, Non-destructive testing of welds Radiographic testing Part 2: X- an
32、d gamma-ray techniques with digital detectors (ISO 17636-2:2013) EN ISO 19232-1, Non-destructive testing Image quality of radiographs Part 1: Determination of the image quality value using wire-type image quality indicators (ISO 19232-1) EN ISO 19232-5, Non-destructive testing Image quality of radio
33、graphs Part 5: Determination of the image unsharpness value using duplex wire-type image quality indicators (ISO 19232-5) BS EN 16407-2:2014EN 16407-2:2014 (E) 6 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 basic spatial resolution of a di
34、gital detector SRbdetectorhalf of the measured detector unsharpness in a digital image which corresponds to the effective pixel size and indicates the smallest geometrical detail, which can be resolved with a digital detector at magnification equal to one Note 1 to entry: For this measurement, the d
35、uplex wire IQI is placed directly on the digital detector array or imaging plate. Note 2 to entry: The measurement of unsharpness is described in EN ISO 19232-5, see also ASTM E2736 18 and ASTM E1000 16. 3.2 computed radiography CR storage phosphor imaging plate system complete system comprising a s
36、torage phosphor imaging plate (IP) and a corresponding read-out unit (scanner or reader), which converts the information from the IP into a digital image 3.3 detector D radiographic image detector consisting of a NDT film system (see EN ISO 11699-1) or a digital radiography system using an imaging p
37、late system (CR system) or a DDA system Note 1 to entry: Film systems and IPs can be used as flexible and curved detectors or in planar cassettes. 3.4 digital detector array system DDA system electronic device converting ionizing or penetrating radiation into a discrete array of analogue signals whi
38、ch are subsequently digitized and transferred to a computer for display as a digital image corresponding to the radiologic energy pattern imparted upon the input region of the device 3.5 DWDI double wall double image technique technique where the radiation source is located outside the pipe and away
39、 from the pipe, with the detector on the opposite side of the pipe and where the radiograph shows details from both the pipe walls on the detector and source sides of the pipe Note 1 to entry: See Figure 3. 3.6 DWSI double wall single image technique technique where the radiation source is located o
40、utside the pipe close to the pipe wall, with the detector on the opposite side of the pipe and where the radiograph shows only detail from the pipe wall on the detector side Note 1 to entry: See Figure 1. BS EN 16407-2:2014EN 16407-2:2014 (E) 7 3.7 nominal wall thickness t thickness of the pipe mate
41、rial only where manufacturing tolerances do not have to be taken into account 3.8 normalized signal-to-noise ratio SNRNsignal-to-noise ratio, SNR, normalized by the basic spatial resolution, SRb, as measured directly in the digital image and/or calculated from the measured SNR, SNRmeasured, by: N me
42、asuredb88,6mSNR =SNRSR3.9 object-to-detector distance b distance between the radiation side of the test object and the detector surface measured along the central axis of the radiation beam 3.10 outside diameter Denominal outside diameter of the pipe 3.11 penetrated thickness w thickness of material
43、 in the direction of the radiation beam calculated on the basis of the nominal thickness Note 1 to entry: For double wall radiographic inspection of a pipe, the minimum value for w is twice the pipe wall thickness. For multiple wall techniques, the penetrated thickness is calculated from the nominal
44、 wall thickness t. 3.12 pipe centre to detector distance PDD distance between the pipe centre and the detector 3.13 pixel size geometrical centre-to-centre distance between adjacent pixels in a row (horizontal pitch) or column (vertical pitch) of the scanned image SOURCE: EN 14096-2:2003, 3.2 3.14 s
45、ignal-to-noise ratio SNR ratio of mean value of the linearized grey values to the standard deviation of the linearized grey values (noise) in a given region of interest in a digital image 3.15 source size d size of the radiation source SOURCE: EN 12679:1999, 2.1 BS EN 16407-2:2014EN 16407-2:2014 (E)
46、 8 3.16 source-to-detector distance SDD distance between the source of radiation and the detector measured in the direction of the beam 3.17 source-to-object distance f distance between the source of radiation and the source side of the test object measured along the central axis of the radiation be
47、am 3.18 source-to-pipe centre distance SPD distance between the source of radiation and the pipe centre (pipe axis) measured in the direction of the beam 3.19 storage phosphor imaging plate IP photostimulable luminescent material capable of storing a latent radiographic image of a material being exa
48、mined and, upon stimulation by a source of red light of appropriate wavelength, generates luminescence proportional to radiation absorbed 3.20 total effective penetrated thickness wtottotal equivalent thickness of metallic material in the direction of the radiation beam calculated on the basis of th
49、e nominal thickness, with allowance for any liquid or other material present in the pipe and any insulation 4 Classification of radiographic techniques The double wall radiographic techniques are divided into two classes: basic techniques DWA; improved techniques DWB. The basic techniques are intended for double wall radiography of generalized and localized wall loss. For the basic techniques, DWA, when using Ir 192 sources for pipes with penetrated thicknesses between 15 mm and 35 mm, the sensitivity for detection will be high for
