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BS 7257:1989
Superseded
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Methods for radiographic examination of fusion welded branch and nozzle joints in steel
Hardcopy , PDF
15-12-1997
English
31-12-1989
Foreword
Committees responsible
Methods
1. Scope
2. Definitions
3. Approval of personnel
4. Techniques
5. Film type
6. Radiation sources
6.1 X-rays
6.2 Gamma-ray sources
7. Protection
8. Surface condition
9. Weld image location
10. Identification of radiographs
11. Marking
12. Density of radiographs
13. Image quality indicators
13.1 Sensitivities
13.2 Location of IQI
13.3 Number of IQIs to be used
14. Intensifying screens
15. Cassettes
16. Source-to-film (focus-to-film) and object-to-film
distances
16.1 Source-to-film (focus-to-film) distance
16.2 Object-to-film distance
17. Overlap of film
18. Useful (diagnostic) length of weld to be examined
on each radiograph and number of exposures required
18.1 Useful (diagnostic) length
18.2 Beam alignment
19. Interception of unwanted and scattered radiation
20. Processing
21. Viewing
22. Approved radiographic procedures
23. Report
24. Examination with film inside and source of
radiation outside
24.1 Technique 1. X-rays using fine grain direct-type
film
24.2 Technique 3. X-rays using medium-speed direct-type
film
24.3 Technique 4. Gamma-rays using fine-grain direct-
type film
25. Examination with film outside and source of
radiation inside
25.1 Technique 7. X-rays using fine-grain direct-type
film
25.3 Technique 10. Gamma-rays using fine-grain direct-
type film
26. Examination with film and source of radiation
both outside
26.1 Technique 13. X-rays using fine-grain direct-type
film
26.2 Techique 15. X-rays using medium-speed direct-type
film
26.3 Technique 16. Gamma-rays using fine-grain direct-
type film
Appendices
A. Explanatory information on the techniques
B. Guide to choice of technique
C. Alternative procedure for placement of IQI
D. Example of record form for radiographic examination
E. Flaw sensitivity in radiography: principles and
background
Tables
1. Individual techniques
2. Minimum and maximum penetrated thicknesses for
gamma-ray sources
3. IQI sensitivity values with IQIs of types I and II
which should be obtained with single wall methods
4. Intensifying screens
Figures
1. Penetrated thickness
2. Minimum values of source-to-film (focus-to-film)
distances with a 1 mm effective diameter X-ray
source for single wall and double wall, single
image methods
3. Minimum values of source-to-film distances with
gamma-ray sources
4. Typical preparation showing variation of weld
geometry around the circumference
5. Typical alignment of exposures required to give full
coverage across the weld width
6. Maximum X-ray tube voltage
7. Double wall, single image
8. Selection of appropriate technique
9. Forged branch and nozzle connections
10. Set-on, set-in, and set-through branch and nozzle
connections
11. Set-on connection
12. Set-in connection
13. Set-in connection welded from both sides
14. Set-through connection welded from both sides
15. Panoramic technique: showing change in source
position required to maintain beam orientation at
various positions around the branch periphery
16. Partial penetration weld
17. Set-on nozzle
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