NB/T 47013.11-2023 English PDF (NBT47013.11-2023)

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NB/T 47013.11-2023: Nondestructive testing of pressure equipments - Part 11: X-ray computed radiographic testing
NB/T 47013.11-2023
NB
ENERGY INDUSTRY STANDARD OF
THE PEOPLE’S REPUBLIC OF CHINA
ICS 77.040.20
CCS H 26
Replacing NB/T 47013.11-2015
Nondestructive testing of pressure equipments - Part 11:
Digital radiographic testing
ISSUED ON: OCTOBER 11, 2023
IMPLEMENTED ON: APRIL 11, 2024
Issued by: National Energy Administration
Table of Contents
Foreword ... 4
Introduction ... 7
1 Scope ... 8
2 Normative references ... 8
3 Terms and definitions ... 9
4 General requirements ... 14
5 Testing method ... 20
6 Image quality and evaluation ... 26
7 Defect identification and measurement ... 35
8 Result evaluation and quality grading ... 36
9 Image preservation and storage ... 36
10 Testing records and reports ... 37
Appendix A (Normative) Verification method of system resolution ... 39
Appendix B (Informative) Typical penetration method ... 41
Appendix C (Normative) Calculation of b value ... 44
Appendix D (Informative) Calculation of minimum number of penetrations of girth
welds ... 47
Appendix E (Normative) Identification of double-linear image quality meter ... 51
Appendix F (Normative) Test method of normalized signal-to-noise ratio ... 53
References ... 54
Nondestructive testing of pressure equipments - Part 11:
Digital radiographic testing
1 Scope
1.1 This document specifies the digital radiographic testing technology and quality
grading requirements for the fusion welding joints of pressure-bearing metallic pressure
components of pressure-bearing equipment. The metal materials used to make welding
joints include steel, copper and copper alloys, aluminum and aluminum alloys, titanium
and titanium alloys, nickel and nickel alloys.
1.2 This document is applicable to the digital radiographic testing of butt joints and butt
welds (hereinafter referred to as "butt welds") of plates and tubes, in the manufacture,
installation, in-service testing of pressure-bearing components of pressure-bearing
equipment.
1.3 The imaging device applicable to this document is a digital detector.
1.4 The radiation sources applicable to this document are X-ray sources and Ir192 and
Se75 γ-ray sources, where the maximum tube voltage of the X-ray machine does not
exceed 600 kV.
1.5 The digital radiographic testing of welded joints of pressure-bearing equipment
supports and structural parts, as well as butt welds of inserted and placed pipe corner
joints (hereinafter referred to as "pipe seat corner welds") can make reference to this
document.
2 Normative references
The contents of the following documents constitute the essential provisions of this
document through normative references in the text. Among them, for dated references,
only the version corresponding to that date applies to this document; for undated
references, the latest version (including all amendments) applies to this document.
GB/T 14058 Apparatus for gamma radiography
GB/T 23901.1 Non-destructive testing - Image quality of radiographs - Part 1:
Determination of the image quality value using wire-type image quality indicators
GB/T 23901.5 Non-destructive testing - Image quality of radiographs - Part 5:
Determination of the image unsharpness and basic spatial resolution value using
4.2.3.6 The DR system supplier shall provide an effective detector correction method.
4.2.3.7 The test conditions and methods for DR system performance indicators, such as
bad pixels, sensitivity, resolution ratio, linear range, signal-to-noise ratio, thickness
tolerance, image sticking, etc., shall be implemented in accordance with the relevant
national or industry standards; the requirements for working temperature and humidity
shall be given.
4.2.3.8 The DR system quality certification document shall at least provide the detector
type, scintillator screen parameters (if any), pixel size, imaging area, applicable range
of radiation energy, quantum conversion efficiency, acquisition frame rate and other
technical parameters.
4.2.4 Computer system
The basic configuration of the computer system is determined according to the
performance and acquisition frame rate requirements of the adopted detector system. It
should be equipped with a memory capacity of not less than 512 MB, a hard disk of not
less than 40 GB, a high-brightness and high-resolution display, a burner, a network card,
etc.
The display shall meet the following minimum requirements:
a) Brightness not less than 250 cd/m2;
b) Gray level not less than 8 bit;
c) Image display resolution not less than 1024 × 768;
d) Display pixel pitch less than 0.3 mm.
4.2.5 System software requirements
4.2.5.1 The system software is the core unit of the digital imaging detection system for
radiographic detection, which has the functions such as image acquisition, image
processing, defect geometry measurement, defect marking, image storage, auxiliary
evaluation.
4.2.5.2 It shall include basic digital image processing functions, such as superposition
noise reduction, contrast and brightness adjustment.
4.2.5.3 It shall include signal-to-noise ratio measurement, resolution ratio measurement,
defect marking, size measurement, size calibration functions.
4.2.5.4 It shall have an image magnification function of not less than 4 times.
4.2.5.5 It shall have the browsing and search functions for the collected image-related
information.
4.2.5.6 It should have the function of converting multiple image formats.
4.2.5.7 The test report can be automatically generated.
4.2.5.8 The raw image shall be saved.
4.2.6 Test fixture
4.2.6.1 It shall be designed according to the workpiece to be inspected and meet the
inspection requirements.
4.2.6.2 It should have functions such as translation, rotation, continuously adjustable
speed; ensure high operating accuracy and stability.
4.2.6.3 The stepping motion of the test fixture shall match the data acquisition of the
detector.
4.2.6.4 For the testing of in-service equipment, the testing instruments and equipment
shall be reasonably fixed, according to the on-site environment and testing conditions.
4.2.7 Image quality meter
4.2.7.1 The image quality meters used in this document include linear image quality
meters and dual-linear image quality meters. The image quality meter supplier shall
provide corresponding quality certification documents.
4.2.7.2 The model and specifications of the linear image quality meter shall comply
with the provisions of GB/T 23901.1 and JB/T 7902. The model and specifications of
the dual-linear image quality meter shall comply with the provisions of GB/T 23901.5.
4.2.8 Use performance of testing system
The appropriate testing equipment and instruments shall be selected, according to the
performance indicators of each part of the testing system, in combination with the
inspected workpiece and the requirements of this document; test certification
documents that meet the performance indicators of the above equipment and instrument
and the system software functions shall be provided. The use performance of the testing
system shall meet the image quality requirements specified in this document.
4.2.9 Calibration or operation verification
4.2.9.1 The linear range, signal-to-noise ratio, thickness tolerance, image afterimage,
etc. of the detector system performance shall be checked and recorded at least once a
year.
4.2.9.2 The exposure curve in use shall be checked at least once a year. When the
important parts of the X-ray machin...