BS EN 16407-2:2014
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Non-destructive testing. Radiographic inspection of corrosion and deposits in pipes by X- and gamma rays – Double wall radiographic inspection
| Published By | Publication Date | Number of Pages |
| BSI | 2014 | 40 |
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 techniques 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 meaning, “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 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 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 digital radiography (CR) and digital detector arrays (DDA).
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 4 | Contents Page |
| 6 | Foreword |
| 7 | 1 Scope 2 Normative references |
| 8 | 3 Terms and definitions |
| 10 | 4 Classification of radiographic techniques |
| 11 | 5 General 5.1 Protection against ionizing radiation 5.2 Personnel qualification 5.3 Identification of radiographs 5.4 Marking 5.5 Overlap of films or digital images 5.6 Types and positions of image quality indicators (IQI) 5.6.1 Single wire IQI |
| 12 | 5.6.2 Duplex wire IQI (digital radiographs) 6 Recommended techniques for making radiographs 6.1 Test arrangements 6.1.1 General 6.1.2 Double wall single image (DWSI) |
| 13 | Figure 1 — Test arrangement for double wall single image radiography (DWSI) using a curved detector |
| 14 | Figure 2 — Test arrangement for double wall single image radiography (DWSI) using a planar detector 6.1.3 Double wall double image (DWDI) |
| 15 | Figure 3 — Test arrangement for double wall double image radiography (DWDI) |
| 16 | 6.1.4 Alignment of beam and film/detector 6.2 Choice of radiation source Table 1 — Total effective penetrated thickness ranges for gamma-ray and high energy X-ray sources for steel pipes |
| 17 | Figure 4 — Maximum X-ray voltage U for X-ray devices up to 1 000 kV as a function of penetrated thickness w and material 6.3 Film systems and screens |
| 18 | Table 2 — Film system classes and metal screens for double wall radiography of steel, copper and nickel based alloy pipes |
| 19 | Table 3 — Film system classes and metal screens for double wall radiography of aluminium and titanium pipes 6.4 Screens and shielding for imaging plates (computed radiography only) |
| 20 | Table 4 —Metal front screens for CR for double wall radiography for pipes of steel, copper and nickel based alloys Table 5 — Metal front screens for CR for the double wall radiography of aluminium and titanium 6.5 Reduction of scattered radiation 6.5.1 Filters and collimators |
| 21 | 6.5.2 Interception of back scattered radiation 6.6 Source-to-detector distance 6.6.1 Double wall single image |
| 22 | 6.6.2 Double wall double image 6.7 Axial coverage and overlap Figure 5 — Axial cross section showing the maximum permissible axial length of the evaluated area for a single source position, on the film/detector, Ld, and along the pipe, Lp, on the source side of the pipe |
| 23 | 6.8 Circumference coverage 6.8.1 General 6.8.2 DWSI Figure 6 — Minimum number of DWSI exposures circumferentially around a pipe, as a function of the ratios t/De and De/SPD, where SPD is the distance from the source to the pipe axis (centre) |
| 24 | 6.8.3 DWDI 6.9 Selection of digital radiographic equipment 6.9.1 General 6.9.2 CR systems 6.9.3 DDA systems 7 Radiograph/digital image sensitivity, quality and evaluation 7.1 Minimum image quality values 7.1.1 Wire image quality indicators |
| 25 | 7.1.2 Duplex wire IQIs (digital radiographs) 7.1.3 Minimum normalized signal to noise ratio (digital radiographs) 7.2 Density of film radiographs |
| 26 | 7.3 Film processing 7.4 Film viewing conditions 8 Measurement of differences in penetrated thickness 8.1 Principle of technique |
| 27 | 8.2 Measurement of attenuation coefficient 8.3 Source and detector positioning 8.4 Image grey level profiles 8.5 Validation 8.6 Key Points |
| 28 | 9 Digital image recording, storage, processing and viewing 9.1 Scan and read out of image 9.2 Calibration of DDAs 9.3 Bad pixel interpolation 9.4 Image processing 9.5 Digital image recording and storage |
| 29 | 9.6 Monitor viewing conditions 10 Test report |
| 31 | Annex A (normative) Minimum image quality values Table A.1 — DWDI Iridium 192 – source side wire IQIs Table A.2 — DWSI Iridium 192 – detector side wire IQIs |
| 32 | Table A.3 — DWDI Selenium 75 – source side wire IQIs Table A.4 — DWSI Selenium 75 – detector side wire IQIs |
| 33 | Annex B (informative) Penetrated thickness measurements from image grey levels |
| 35 | Annex C (normative) Determination of basic spatial resolution |
| 38 | Bibliography |
