Through the comparative analysis of the main revisions of the new standard cabinet door, 4730.2005 rolling equipment non-destructive testing and the Japanese dish 4730.1994 "Non-destructive testing of the cooking container", some of the new standard provisions are combined with the actual work. Need to pay attention to and deepen the understanding of the content, have a thorough understanding of the JB/T4730-2005 "Non-destructive testing of pressure equipment" in the ray detection articles, have a certain guiding significance for the actual work JB, r4730-2005 "accommodating pressure equipment Non-destructive testing was implemented on November 1, 2005, in place of JB4730-1994 Non-destructive testing of the production container. The following three aspects were noted in the general idea of the standard revision:
1) technological progress;
2) in line with international standards;
3) Standard system and technical route selection. Two main reference frames were selected for the standard system and technical route: Europe and the United States. Relatively speaking, the European standard is more advanced in technology, structural integrity, narrative rigor, and ease of use than the US standard. Therefore, the JB, r4730.2 radiation detection option is: according to the European reference to the United States.
1. Standard revision
1) The version adds general requirements, and summarizes some basic principles of non-destructive testing technology and common aspects of management, which makes the whole standard structure more compact.
It also facilitates non-Non-destructive testing professionals to quickly understand and apply new standards.
2) For the testing personnel, the original version stipulates the technical qualifications and vision. After the revision, detailed requirements are specified. Corresponding to the quality management documents, the contents of the relevant non-destructive testing personnel should also be modified to require pre-post radiation protection training and radiation. Staff certification, as well as visual acuity.
3) Film: The original film is selected according to the exposure time and the quality of the film, which misleads the basic role of film in radiography. The new standard classification is divided into four categories based on film, and is selected according to the technical level, completely replacing the original three-level classification method. The standard also stipulates that T2 should be applied to the radiation detection of the material with high crack sensitivity. Class or higher class film.
4) For the viewing light, the original version only specifies the maximum brightness ≥ 1 [t0000ctl / m. . With reference to JB, 17903, there are some main performance requirements, such as brightness uniformity, case temperature rise,
Noise, insulation resistance, etc., while the brightness of the viewing light should meet the requirements of the film. This modification is mainly because the brightness of the domestically produced viewing light does not meet the requirements of the 94 version, resulting in inoperable problems. It is stipulated that in practice, it meets both the requirements of general standards and operability.
5) Blackness meter. Strictly speaking, the uncertainty should be specified. The specified index is based on the actual blackness of the film and the foreign standard for the error of the measured value of the blackness.
The period was also revised with reference to the actual experience of some units.
6) Removed the version 94 that can use the fluorescence intensifying screen and the metal fluorescent intensifying screen.
7) Image quality meter. The new version has added a nickel-N material image meter. The comparison test should only be carried out for single-wall transillumination. The double-wall transillumination has no specific test because it has given specific sensitivity regulations. In addition, the quality meter was extended to No. 19, No. 1 was cancelled, and some modifications were made to the requirements of the image quality meter. It should be noted that the image quality meter is selected according to the nominal thickness or the transillumination thickness, excluding the weld height, and
The required sensitivity is improved. In addition, it should be noted that there are three selection criteria, namely, transillumination mode, image quality placement position and radio detection technology bar level. In actual operation, if the wire diameter is not changed while ensuring the sensitivity of the image quality meter, the old image quality meter can be temporarily used, but there is no applicable image quality meter for the newly added Nj material.
8) In the new standard, the low-to-high "radiation detection technology level" of A, AB and B grades is different from the original "radiation quality grade", and A, A and B grade negatives are obtained accordingly. Quality, the ability to achieve different requirements for defect inspection, in line with the different acceptance techniques, the concept of the revision mentioned earlier, but in the usual work, often in the report and quality documents, the use of language errors and the expression of vague concepts, So pay special attention. In addition, the filling of the thickness of the transillumination is different from the original, the image quality index is replaced by the image quality sensitivity, the selection of the image quality meter should be JB, the first group of 17902, and the changes of some terms such as the transillumination method should also pay attention to Timely change.
9) In terms of radiation protection, the original version lacks clear limits and does not comply with the radiation protection principle. It does not meet the limit system provided by the protection standard. There is a conceptual error that may cause an incorrect radiation protection awareness. The new version prevents the occurrence of harmful deterministic effects based on the principles of fairness, optimization and limit of radiation protection, and limits the incidence of random effects to an acceptable level.
10) Transillumination arrangement. The original version simply gives a common transillumination method, and the lack of a system around n cattle is incomplete. The new version makes systematic regulations on a logical level, including transillumination, transillumination, one transillumination length, and special cases (small tubes) to more effectively ensure the detection of defects. In the regulation of the length of one transillumination, the exposure curve for 1ttomm 11) is increased in consideration of the foreign value and the actual working condition of the transillumination thickness ratio in recent years. The original version requires the production or selection of an exposure curve to determine the exposure specification with the exposure curve. The new edition requires the exposure curve to be made according to the standard, and the exposure of the materials to be tested should be made for each of the in-use ray equipment. The exposure specification should be determined according to the exposure curve, and the curve in use should be verified at least once a year. After the important parts of the ray equipment are replaced or after major repairs, the exposure curve should be verified or reworked in time. This is not clear enough in the original version. The new version of the exposure curve is a control measure for process stability. It also tests the stability of the system. The relevant provisions stipulate that the standard system is more rigorous and more important. However, it is often easy to neglect this aspect in daily work, and it should be strictly 今后i in the future.
12) The standard uses a larger space to specify the content of the special case small-diameter tube transillumination, which is also easier to implement. However, no suggestion was made on the transillumination thickness of the transillumination parameters, leaving a little regret for the actual normative operation.
13) In the specification of film quality: the regulations on sensitivity and blackness have been changed, and the concept of “image quality index” has been deleted to correct the error of fog as a false defect. Demand for fog blackness
To the requirements of the film. For the blackness requirement, the x and v rays are no longer distinguished, and the regulations are unified. When the small diameter tube or other workpiece with a large thickness variation is transilluminated with a v-ray, the allowable reduction is made, and the AB level can be reduced to 15. When using multi-film technology, Class A allows superimposed observation and other content. Blackness is the most basic parameter of radiographic image quality. It affects image contrast and graininess noise, which affects sensitivity and improves the sensitivity of blackness to film sensitivity and defects. Both are advantageous, so the upper and lower limits of the blackness specified by the standard have been improved.
2. Pay special attention to the problem
1) The new standard expands the scope of application of the radiation inspection, and further narrowly defines from the original pressure vessel weld to the 'manufacture, installation and in-service welding of the pressure-bearing components of the pressure-bearing equipment”, Includes all non-destructive testing of pressure equipment, boilers, pressure vessels and pressure piping as specified in the /Special Equipment Safety Supervision Regulations, including not only non-destructive testing of pressure equipment manufacturing and installation processes, but also raw materials for pressure-bearing equipment, The inspection of parts and components, as well as non-destructive testing, which is regularly inspected by pressure-bearing equipment. The applicable materials are added to copper, copper, gold and nickel.
2) It is worth mentioning that there are 3 standard 3 discs. In the inspection of pressure equipment, due to limitations in structure, environment, and ray equipment, under certain conditions of testing, the requirements of AB-level radiographic inspection technology cannot be met. The person in charge of the technical party approves the use of Class A technology for radiation testing after taking effective measures, but other non-destructive testing methods should be used for supplementary testing.
3. Conclusion
Compared with the original version, the new version of the ray detection article is used. The new version of the standard simplifies the processing for some technical contents. The new edition clearly defines and stipulates some concepts that were vague in the past. According to the work experience and the actual situation, under the premise of upholding the principle, the new version makes practical and realistic regulations on some technical issues.