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GB/T 34370 consists of the following six parts under the general title Nondestructive Testing of Amusement Equipments:
- Part 1: General Requirement;
- Part 2: Visual Examination;
- Part 3: Magnetic Particle Testing;
- Part 4: Penetrant Testing;
- Part 5: Ultrasonic Testing;
- Part 6: Radiographic Testing.
This part is part 6 of GB/T 34370.
This part is developed in accordance with the rules given in GB/T 1.1-2009.
This part was proposed by and is under the jurisdiction of SAC/TC 250 National Technical Committee on Ropeway and Entertainment Facilities of Standardization Administration of China.
Nondestructive Testing of Amusement Equipments -
Part 6: Radiographic Testing
1 Scope
This part of GB/T 34370 specifies X ray and γ ray testing technology and quality classification requirements for the fusion welded butt joints of amusement equipments.
This part is applicable to radiographic testing for carbon steel, low-alloy steel and stainless steel butt welded joints with a thickness of 2mm~200mm on the amusement equipment.
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 11533 Standard for Logarithmic Visual Acuity Charts
GB/T 12604.2 Non-destructive Testing - Terminology - Terms Used in Radiographic Testing
GB 18871 Basic Standards for Protection Against Ionizing Radiation and for the Safety of Radiation Sources
GB/T 19348.1 Non-destructive Testing - Industrial Radiographic Film - Part 1: Classification of Film Systems for Industrial Radiography
GB/T 19348.2 Non-destructive Testing Industrial Radiographic Films - Part 2: Control of Film Processing by Means of Reference Values
GB/T 19802 Non-destructive Testing - Industrial Radiographic Illuminators - Minimum Requirements
GB / T 20306 Amusement Devices Terminology
GB/T 20737 Non-destructive Testing - General Terms and Definitions
GB/T 23910 Non-destructive Testing - Metal Intensifying Screens for Radiographic Testing
GB/T 34370.1 Nondestructive Testing of Amusement Equipments - Part 1: General Requirement
GBZ 117 Radiological Protection Standards for Industrial X-ray Detection
GBZ 132 Radiological Protection Standards for Industrial Gamma Defect Detecting
JB/T 7902 Non-destructive Testing - Image Quality Indicators(Wire Type) for Radiographic Testing
3 Terms and Definitions
For the purposes of this document, the terms and definitions given in GB/T 12604.2, GB/T 20306 and GB/T 20737, as well as the following apply.
3.1
penetrated thickness
W
nominal thickness of materials in the direction of radiation exposure. In multilayer radiography, penetrated thickness is the sum of nominal thickness of penetrated layers of materials
3.2
object-to-film distance
b
distance between the source side surface on the to-be-inspected position of the object and the film, which is determined along the center of ray beam
3.3
source-to-object distance
f
distance between source for the to-be-tested position of the object and the surface on the near-source side of to-be-tested object, which is determined along ray beam center
3.4
focal distance
F
distance between the source and the film measured along the center of the radiation beam
3.5
source size
d
effective focal spot size of source
3.6
ratio of max. and min. penetrated thickness
K
ratio of maximum thickness and minimum thickness of base metal that radiation beam penetrates within the range of once-through penetration length
3.7
film evaluation scope
scope that must be observed and assessed on the film
3.8
round flaw
flaws such as air hole, slag inclusion and tungsten inclusion with length-width ratio no greater than 3
3.9
stripy flaw
flows such as air hole, slag inclusion and tungsten inclusion with length-width ratio greater than 3
4 Method Summary
Radiographic testing is a method based on the principle of ray absorption ability of a material, which is used to determine the presence of flaw in the workpiece as well as the position and size of the flaw by obtaining the intensity change of transmitted ray resulted from the changes in the ray absorption of the object caused by the defective portion; as shown in Figure 1. It can be divided into X -ray testing and γ -ray testing according to the source, or film radiography testing imaging, computed radiography (CR) and digital radiography (DR) according to imaging mode, or fixed testing and mobile testing according to testing mode.
Figure 1 Schematic Diagram of Radiographic Testing
5 Safety Requirements
The safety requirements during testing shall at least include:
a) testing personnel shall observe the safety requirements of the site for the testing workpiece, and wear protective clothing and relevant protective equipment according to the requirements of the testing site;
b) the amusement equipment shall be tested after operation; the temperature of the tested workpiece shall be checked to avoid ambustion.
c) the radiation hygiene protection shall comply with the relevant requirements of GB 18871, GBZ 117 and GBZ 132.
d) in case of X-ray testing on site, the division of control area and management area as well as the arrangement of warning sign(s) shall be carried out according to the requirements of GBZ 117. Testing personnel shall wear personal dosimeters and take alarm dosimeter(s).
e) in case of γ-ray testing on site, the division of control area and supervision area and the arrangement of warning sign(s) shall be carried out according to the requirements of GBZ 132. During testing works, the radiation level shall be determined around the boundary of the control area. Testing personnel shall wear personal dosimeters and take alarm dosimeter(s).
f) this chapter does not list all the safety requirements for testing, therefore, the users of this part shall establish safety criterion prior to testing.
6 Personnel Requirements
The personnel engaged in radiographic testing shall, in addition to complying with the relevant requirement of GB/T 34370.1, shall receive radiological safety knowledge training and obtain the radiation staff permit before taking up their posts. The uncorrected and corrected near vision and distance vision of radiographic testing personnel shall not be less than 5.0 (with decimal record of 1.0) and the testing method shall be in accordance with the requirements of GB 11533. The personnel engaged in the film evaluation shall check his eyesight once every 12 months.
Foreword i
1 Scope
2 Normative References
3 Terms and Definitions
4 Method Summary
5 Safety Requirements
6 Personnel Requirements
7 Testing Equipment and Apparatus
8 Testing Procedure
9 Testing
10 Radiographic Testing Quality Grading of Steel Fusion Welded Butt Joints
11 Radiographic Testing Quality Grading of Circumferential Fusion Welded Butt Joints of Steel Pipe Fittings
12 Radiographic Testing Report
Annex A (Informative) Schematic Diagram of Typical Radiography Modes
Annex B (Informative) Determination Method for Determination of Radiographing Times of Circumferential Butt Welded Joints
Annex C (Normative) Calculation Method of Focus Size
Annex D (Normative) Type and Specification of Special Image Quality Indicator
Annex E (Normative) Placement Position of Overlapping Mark
Annex F (Normative) Type and Specification of Reference Blocks