Detail of NB/T 47013.11-2015/XG1-2018

Introduction of NB/T 47013.11-2015/XG1-2018

Notice of Amendment to the Professional Standard NB/T 47013.11-2015 Nondestructive Testing of Pressure Equipments Part 11: Standard Practice for X-ray Digital Radiography Amendment 1 This amendment was approved by No.7 Announcement by the National Energy Administration on May 14, 2018 and shall be implemented as of July 1, 2018. ○1 New provisions are added following "GB/T 23903 Resolution Indicators for Ray Image" in Clause 2: GB/T 26592 Non-destructive Testing Instruments - Properties Test Methods of Industrial X-ray Apparatus GB/T 26594 Non-destructive Testing Instruments - Properties Test Methods of Industrial X-ray Tube New provision is added following "NB/T 47013.2 Nondestructive Testing of Pressure Equipments - Part 2: Radiographic Testing": JB/T 11608 Non-destructive Testing Instruments Industrial X-ray Apparatus for Radiographic Testing ○2 In 4.1.1, the expression: "obtain radiation staff card" is changed to "obtain the corresponding certificate in accordance with the requirements of relevant laws and regulations". ○3 In 4.2, the expression: "Testing system" is changed to "Testing system and apparatus" ○4 New provision 4.2.1.3 is added following 4.2.1.2: The performance indexes of X-ray machine adopted shall meet the requirements of JB/T 11608. See GB/T 26594 and GB/T 26592 for the testing conditions and testing methods for the service performance. ○5 4.2.2.4 is replaced by the following new provision: Bad pixel requirements: In the 3×3 pixel area of the area array detector, the number of adjacent bad pixels shall not exceed 3; the number of the bad pixels in a line (column) shall not exceed 3, and those bad pixels shall not be located within 200 pixels from the center; the number of bad pixels in the imaging area shall not exceed 1% of the total pixels. In a linear array detector, the number of adjacent bad pixels shall not exceed 2. The detector system supplier shall provide the bad pixel list and bad pixel correction method upon delivery. ○6 New provisions 4.2.2.6 and 4.2.2.7 are added following 4.2.2.5: "4.2.2.6 The testing conditions and testing methods for performance indexes of the detector system, such as bad pixels, contrast sensitivity, resolution ratio, signal noise ratio, linear range, thickness tolerance , residual image, etc., shall be in accordance with those specified in the corresponding national or professional standards." "4.2.2.7 The quality certificate of the detector system shall include at least the technical parameters such as detector type, conversion screen parameters (if any), pixel size, imaging area, applicable range of ray energy, quantum conversion efficiency, fill factor, acquired frame rate, etc." ○7 In 4.2.4.6, the expression "according to assessment result" is changed to "automatically". ○8 4.2.6 is replaced by the following new provision: 4.2.6 Image quality indicator 4.2.6.1 For the purpose of this part, the image quality indicator includes wire-type image quality indicator and duplex wire-type image quality indicators. 4.2.6.2 The model and specification of the wire-type image quality indicator shall meet the requirements of GB/T 23901.1, while those of the duplex wire-type image quality indicators shall meet the requirements of GB/T 23901.5. ○9 New provisions 4.2.7 and 4.2.8 are added following 4.2.6: “4.2.7 Service performance of the testing system Appropriate testing equipment and apparatus shall be selected according to the performance indexes of each part of the testing system, together with the requirements of the to-be-tested workpiece and this part. The testing certificate certifying the conformity to the performance indexes of the above-mentioned equipment and apparatus and system software functions shall also be provided. The service performance of the testing system shall meet the image quality requirements of this part.” “4.2.8 Calibration or operation verification 4.2.8.1 The bad pixels, linear range, signal noise ratio, thickness tolerance, residual image and other performance indexes of the detector system shall be calibrated at least once a year and recorded. 4.2.8.2 The in-service exposure curve shall be verified at least once a year. The exposure curve shall be replotted in the case any important component of the X-ray machine is replaced or repaired. 4.2.8.3 Bad pixels of the detector are checked at least once every 3 months, and recorded and corrected accordingly. 4.2.8.4 Under one of the following circumstances, the system resolution ratio shall be verified in accordance with the method given in Annex A and recorded. a) alternation in the testing system; b) under normal service conditions, verification shall be carried out at least once every 3 months; c) reuse of the system after shutdown for 1 month. ○10 New provision 5.4.1.3 is added following 5.4.1.2: “If radiography fails to carried out for several times at the angular interval as specified in 5.4.1.1 or 5.4.1.2 due to structural reasons, upon agreement between the contract parties, angular interval specified in 5.4.1.1 or 5.4.1.2 may not be restricted compulsively, but effective measures shall be taken to extend the detectable range of defects as much as possible, and meanwhile signal noise ratio, sensitivity and resolution ratio within the image evaluation scope shall be guaranteed to meet the requirements, and relevant circumstances shall be explained in the testing report.” ○11 5.4.2 is replaced by the following new provision: 5.4.2 "The number of radiography for circumferential welded joints of small-diameter tubes not subjected to 100% testing shall be agreed by contract parties, and relevant records shall be kept.” ○12 "The model and specification of wire-type image quality indicator shall meet the requirements of GB/T 23901.1" in 6.1.1.3 is deleted. ○13 "The model and specification of duplex wire-type image quality indicator shall meet the requirements of GB/T 23901.5" in 6.1.1.4 is deleted. ○14 In 6.1.2.1.2, the expression: "During double-wall single-image radiography" is changed to "During double-wall single-image or double-wall double-image radiography” ○15 6.1.3.1 is replaced by the following new provision: "The duplex wire-type image quality indicator shall be arranged beside the X-ray machine. When the double-wall single-image radiography mode is adopted, the indicator may be arranged beside the detector." ○16 In 6.1.3.2.1, the expression "in the 1/4 position in the length of the tested" is changed to "adjacent to the weld under test". ○17 "For the double-wall double-image radiography mode of small-diameter tube, the penetrated thickness shall be the tube diameter.” is added at the end of 6.1.4.2. ○18 The following is added at the end of 6.1.4.3: "Note: in case of testing crack-sensitive materials or high-strength materials with the lower limit of standard tensile strength Rm ≥ 540MPa, compensation shall not be adopted." ○19 In 6.2.5.2, the expression "radiography specification"” is changed to "radiography parameter". ○20 The following is added at the end of A.5.1 a): "In the case of limited conditions, F may be appropriately reduced, but it shall be ensured that the geometric unsharpness of the testing system is not more than 5% of the pixel size of the detector." ○21 New provision A.6 is added following A.5.2: "The system resolution ratio shall meet the requirements of Tables 4 or 5. Where it is used for testing of double-wall double-image radiography mode for small-diameter tubes, the penetrated thickness in the Table shall be twice the wall thickness of the tube." ○22 In the fifth line of D.1, the expression "P - the pixel size of detector, μm;" is changed to "P - resolution, μm; Note: for the measurement of the normalized signal noise ratio of the system, P represents the system resolution; while for the measurement of the normalized signal noise ratio of the image, it represents the image resolution." ○23 D.2 is replaced by the following new provision: "The measurement of signal noise ratio: take a rectangular area of not less than 20 pixel ×50 pixel in the homogeneous area (for signal noise ratio of an image, it refers to the heat-affected zone or the base material and non-defective zone around the weld), calculate the average and standard deviation of this area, then obtain the measured signal noise ratio SNRm according to the definition of the signal noise ratio."

Contents of NB/T 47013.11-2015/XG1-2018

Foreword I 1 Scope 2 Normative References 3 Terms and Definitions 4 General Requirements 5 Testing Method 6 Image Quality and Assessment 7 Testing Result Assessment and Quality Grading (Acceptance) 8 Image Preservation and Storage 9 Testing Record and Report Appendix A (Normative) Checking Method of System Resolution Ratio Appendix B (Informative) Typical Radiography Mode Appendix C (Normative) Identification of Duplex Wire Type Image Quality Indicators Appendix D (Normative) Test Method for Normalized Signal to Noise Ratio Appendix E (Informative) Testing Report Format