Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
GB/T 3323 consists of the following parts, under the general title Non-destructive testing of welds - Radiographic testing:
Part 1: Part 1: X- and gamma-ray techniques with film;
Part 2: X- and gamma-ray techniques with digital detectors.
This is Part 1 of GB/T 3323.
This part is developed in accordance with the rules given in GB/T 1.1-2009.
This part replaces GB/T 3323-2005 Radiographic examination of fusion welded joints in metallic materials and the following main technical changes have been made with respect to GB/T 3323-2005:
——The scope is modified (see Clause 1; Clause 1 of Edition 2005);
——The normative references are modified (see Clause 2; Clause 2 of Edition 2005);
——Some terms, definitions and symbols are modified (see Clause 3; Clause 3 of Edition 2005);
——Symbols and abbreviations are added (see Clause 4);
——Requirements for the minimum image quality are modified (see 6.9; 5.9 of Edition 2005);
——The personnel qualification is modified (see 6.10; 5.10 of Edition 2005);
——The saddle fillet weld is changed to set-on tube socket weld (see Figures 4, 7 and 10; Figures 4, 7 and 10 of Edition 2005);
——The X-ray machine with tube voltage below 1,000kV is modified (see 7.2.1; 6.2.1 of Edition 2005);
——Appendix A is modified, the wire-type IQI is changed to wire IQI and the value of IQI is changed to image quality value;
——Appendix D to Appendix E of Edition 2005 are deleted.
This part has been redrafted and modified adoption of ISO 17636-1: 2013 Non-destructive testing of welds - Radiographic testing - Part 1: X- and gamma-ray techniques with film.
Compared with ISO 17636-1:2013, the structure of this part is slightly adjusted, i.e., 6.9 is adjusted to 6.7, and others are postponed; the order of Appendix A and Appendix B is adjusted.
The main technical differences of this part from ISO 17636-1:2013 and their justifications are as follows:
——The adjustment in "Normative References" of this part has technical differences to meet the technical specification in China; the adjustment situations are embodied in a concentrated way in Clause 2 - "Normative references" and the specific adjustments are as follows:
● GB/T 19943 identical to the international standard ISO 5579 is added and for reference (see Clause 1);
● GB/T 12604.2 identical to the international standard is used to replace ISO 5576 (see Clause 3);
● GB/T 23901.1 identical to the international standard is used to replace ISO 19232-1 (see 6.8);
● GB/T 23901.2 identical to the international standard is used to replace ISO 19232-2 (see 6.8);
● GB/T 23901.4 identical to the international standard is used to replace ISO 19232-4 (see 6.7);
● GB/T 19802 identical to the international standard is used to replace ISO 5580 (see 6.9, 7.8 and 7.10);
● GB/T 9445 identical to the international standard is used to replace ISO 9712 (see 6.10);
● GB/T 19348.1 which is modified in relation to the international standard is used to replace ISO 11699-1 (see 7.3, Table 3 and Table 4);
● GB/T 25758 (all parts) identical to the international standard is used to replace EN 12543.1~EN 12543.5 (see 7.6);
● GB/T 19348.2 identical to the international standard is used to replace ISO 11699-2 (see 7.9).
The following editorial changes have also been made in this part:
——ISO 5579 and ISO 19232-3 in “Bibliography” are deleted.
This part was proposed by and is under the jurisdiction of the National Technical Committee on Welding of Standardization Administration of China (SAC/TC 55).
The previous editions of this part are as follows:
——GB/T 3323-1982, GB/T 3323-1987 and GB/T 3323-2005.
Non-destructive Testing of Welds - Radiographic Testing - Part 1: X- and Gamma-ray Techniques with Film
焊縫無損檢測 射線檢測 第1部分：X和伽瑪射線的膠片技術(shù)
1 Scope
This part of GB/T 3323 specifies techniques of radiographic examination of fusion welded joints of metallic materials.
This part is applicable to the radiographic examination of welded joints of plates and pipes or other welded joints.
This part does not specify acceptance levels for radiographic examination of welded joints of metallic materials.
If contracting parties apply lower test criteria, it is possible that the quality of tested image is declined significantly.
Note: This part meets the requirements of GB/T 19943, and the detector used is film.
2 Normative References
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 9445 Non-destructive testing - Qualification and certification of NDT personnel (GB/T 9445-2015, ISO 9712:2012, IDT)
GB/T 12604.2 Non-destructive testing - Terminology - Terms used in radiographic testing (GB/T 12604.2-2005, ISO 5576:1997, IDT)
GB/T 19348.1 Non-destructive testing - Industrial radiographic film - Part 1: Classification of film systems for industrial radiography (GB/T 19348.1-2014, ISO 11699-1:2008, MOD)
GB/T 19348.2 Non-destructive testing - Industrial radiographic films - Part 2: Control of film processing by means of reference values (GB/T 19348.2-2003, ISO 11699-2:1998, IDT)
GB/T 19802 Non-destructive testing - Industrial radiographic illuminators - Minimum requirements (GB/T 19802-2005, ISO 5580:1985, IDT)
GB/T 19943 Non-destructive test - Radiographic examination of metallic materials by X- and gamma-rays - Basic rules (GB/T 19943-2005, ISO 5579:1998, IDT)
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 23901.1-2019, ISO 19232-1:2013, IDT)
GB/T 23901.2 Non-destructive testing - Image quality of radiographs - Part 2: Determination of the image quality value using step/hole-type image quality indicators (GB/T 23901.2-2019, ISO 19232-2:2013, 1DT)
GB/T 23901.4 Non-destructive testing - Image quality of radiographs - Part 4: Experimental evaluation of image quality values and image quality tables (GB/T 23901.4-2019, ISO 19232-4:2013, IDT)
GB/T 25758
(All parts) Non-destructive testing - Characteristics of focal spots in industrial X-ray systems for use in non-destructive testing
EN 12679 Non-destructive testing - Radiographic testing - Determination of the size of industrial radiographic gamma sources
3 Terms and Definitions
For the purposes of this document, the terms and definitions given in GB/T 12604.2 and the followings apply.
3.1
Nominal thickness
t
Nominal thickness of the parent material only where manufacturing tolerances do not have to be taken into account
3.2
Penetrated thickness
w
Thickness of material in the direction of the radiation beam calculated on the basis of the nominal thicknesses of materials
3.3
Penetration thickness change
Change of the actual penetrated thickness relative to the nominal thickness due to beam angle
3.4
Object-to-film distance
b
Distance between the surface of the tested object at the side of radiation source and the film measured along the central axis of the radiation beam
3.5
Source size
d
Size of the radiation source or focal spot size
3.6
Source-to-object distance
f
Distance between the radiation source (or focus) and the tested object at the side of radiation source measured along the central axis of the radiation beam
3.7
Source-to-film distance
SFD
Distance between the radiation source (or focus) and the film measured in the direction of the radiation beam
3.8
External diameter
De
Nominal external diameter of the pipe
4 Symbols and Abbreviations
For the purposes of this document, the symbols and abbreviations given in Table 1 apply.
Table 1 Symbols and abbreviations
b object-to-film distance
b’ object-to-film distance perpendicular to test object
De external diameter
d source size
F film
f source-to-object distance
f ' source-to-object distance perpendicular to test object
fmin minimum source-to-object distance
IQI image quality indicator
S radiation source
SFD source-to-film distance
t nominal thickness
penetration thickness change
w penetrated thickness
5 Classification of Radiographic Testing Techniques
Radiographic testing techniques are divided into two classes:
——Class A: basic techniques;
——Class B: improved techniques.
Class B techniques are used when the sensitivity of class A techniques cannot meet the requirements. Better techniques compared to class B are possible and may be agreed between the contracting parties by specification of all appropriate testing parameters.
The choice of radiographic testing technique shall be agreed between the contracting parties.
If, for technical or structural reasons, it cannot meet the radiography conditions of class B techniques, such as the type of radiation source and source-to-object distance, upon the agreement of contracting parties, the radiography conditions specified in class A techniques can be selected. In such case, the loss of sensitivity shall be compensated by increasing the minimum intensity of negative film to 3.0 or selecting a better film system with minimum intensity of 2.6. The other conditions for class B shall remain unchanged, especially the image quality achieved (see Tables A.1 to A.12 in Appendix A). Since the sensitivity after compensation is better than that of class A techniques, it may be considered that the object is radiographed according to class B techniques. For the radiographic arrangements in 7.1.4 and 7.1.5, if the source-to-film distance is reduced according to 7.6, it is not necessary to compensate the sensitivity according to the above method.
6 General
6.1 Radiological safety protection
Without proper protective measures, X-rays or gamma rays will be highly injurious to health. The use of X-ray equipment or radioactive sources shall meet the requirements of regulations for radiological protection. When carrying out radiographic testing, the safety protection measures stipulated in relevant laws and regulations shall be strictly applied.
6.2 Timing of surface preparation and testing
In general, surface preparation of the object is not necessary, but when surface imperfections or coatings affect the detection of defects, the surface of the object shall be ground smooth or the coating shall be removed.
Unless otherwise specified, radiographic testing shall be carried out after completion of manufacturing, such as after grinding or heat treatment.
6.3 Location of the weld in the negative film
When the weld boundary cannot be clearly displayed on the negative film, location markings made of high density materials shall be placed on either side of the weld.
6.4 Identification of negative film
For each section of the object being radiographed, identification markings composed of letters, numbers and symbols shall be placed, such as product number, weld number, repair marking and radiography date, to characterize the object and position of the tested image. Marked images shall be located outside the effective area of interest and ensure that each section is clearly marked.
Foreword i
1 Scope
2 Normative References
3 Terms and Definitions
4 Symbols and Abbreviations
5 Classification of Radiographic Testing Techniques
6 General
7 Recommended Radiographic Testing Techniques
8 Testing report
Annex A (Normative) Minimum Image Quality Value
Annex B (Normative) Recommended Number Of Exposures for 100% Radiographic Testing of a Circumferential Butt Weld
