GB/T 12605-2008 in English

《GB/T 12605-2008无损检测 金属管道熔化焊环向对接接头射线照相检测方法》由TC56（全国无损检测标准化技术委员会）归口，主管部门为国家标准化管理委员会。
本标准规定了金属管道熔化焊环向对接接头射线照相检测方法及质量评定分级。本标准适用于壁厚为(2～175)mm的金属管子及管道的环向对接接头。对焊制管件、焊管焊接接头也可参照使用。本标准不适用于摩擦焊、闪光焊等机械方法施焊的对接接头。

1 Scope

This standard specifies the test methods and quality evaluation classification for radiographic testing of circumferential fusion-welded butt joints in metallic pipes and tubes.
This standard is applicable to the circumferential butt joints in metallic pipes and tubes with a wall thickness of (2~175)mm. It may also be referenced by butt-welded pipe fittings (tees and elbows) and welded joints of welded pipes and tubes (longitudinal joints and spiral joints).
This standard does not apply to butt joints welded by mechanical methods such as friction welding and flash welding.

2 Normative References

The following documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections), or revisions, of any of these publications do not apply to this standard. However parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the document referred to applies.
GB/T 9445 Non-destructive testing - Qualification and certification of NDT personnel (GB/T 9445-2008, ISO 9712: 2005, IDT)
GB 11533-1989 Standard for logarithmic visual acuity charts
GB/T 12604.2 Non-destructive testing - Terminology - Terms used in radiographic testing (GB/T 12604.2-2005, ISO 5576:1997, IDT)
GB 18871-2002 Basic standards for protection against ionizing radiation and for the safety of radiation sources (neq IAEA Safety Series)
GB/T 19348.1-2003 Non-destructive testing - Industrial radiographic film - Part 1: Classification of film systems for industrial radiography (ISO 11699-1:1998, IDT)
GBZ 98-2002 Health standards for radiation workers
GBZ 117-2002 Radiological protection standards for industrial X-ray detection
GBZ 132-2002 Radiological protection standards for industrial gamma defect detecting
JB/T 7902-2006 Non-destructive testing - Image quality indicators (wire type) for radiographic testing

3 Terms and Definitions

For the purposes of this standard, 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 with the manufacturing tolerances not taken into account
3.2
penetrated thickness
W
thickness of material in the radiation beam (radiographic) direction calculated on the basis of the nominal thicknesses
3.3
object-to-film distance
b
distance between the side of the radiation source of the tested object and the film surface measured in the direction of the radiation beam
3.4
source size
d
size of the radiation source
3.5
source-to-film distance
F
distance between the radiation source and the film measured in the direction of the radiation beam
3.6
source-to-object distance
f
distance between the radiation source and the tested object at one side of the radiation source measured in the direction of the radiation beam
3.7
diameter
D0
nominal external diameter of the tube and pipe
3.8
small diameter tube
tube with D0 less than or equal to 100mm
3.9
ratio of max and min penetrated thickness
K
ratio of the maximum thickness and the minimum thickness of parent material that radiation beam penetrates over the effective area of a single exposure

Foreword i
1 Scope
2 Normative References
3 Terms and Definitions
4 Radiographic Testing Personnel
5 Radiation Protection
6 Radiographic Process
7 Negative Film Quality and Observation
8 Quality Classification
9 Negative Film Preservation and Testing Report
Annex A (Informative) Calculation Method of Maximum Source Size
Annex B (Normative) Single Wire IQI
Annex C (Normative) Special Contrast Block
Annex D (Informative) Method for Determination of Radiographic Exposure Times of Circumferential Butt Welded Joints in Pipes and Tubes
Annex E (Informative) Approximate Calculation Method for Detection Range of Single Imaging by Elliptical Radiography for Small Diameter Tubes