GB 22448-2025 Non-destructive testing instruments—Protection rules for industrial X-ray radiographic equipment below 500kV English, Anglais, Englisch, Inglés, えいご
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ICS 19.100
CCS N 78
National Standard of the People's Republic of China
GB 22448-2025
Replaces GB 22448-2008
Non-destructive testing instruments - Protection rules for industrial X-ray radiographic equipment below 500kV
无损检测仪器 500kV以下工业X射线 探伤机防护规则
(English Translation)
Issue date: 2025-08-01 Implementation date: 2026-08-01
Issued by the State Administration for Market Regulation
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Protection requirements for X-ray machines
5 Protection requirements for X-ray radiographic operation sites
6 X-ray protection monitoring during use
7 Safe operation requirements for X-ray machines
8 Radiation protection detection of X-ray machines
Non-destructive testing instruments - Protection rules for industrial X-ray radiographic equipment below 500kV
1 Scope
This document specifies the protection requirements for industrial X-ray radiographic equipment below 500kV, protection requirements for X-ray radiographic operation sites, radiation protection monitoring during use, safe operation requirements for X-ray machines, and radiation protection detection of X-ray machines, etc.
This document is applicable to the design, manufacture, installation and use of industrial X-ray radiographic equipment below 500kV (including fixed X-ray radiographic machines, mobile X-ray radiographic machines and portable X-ray radiographic machines). Non-radiographic non-destructive testing equipment within the same radiation source range shall be used as a reference.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions 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 18871 Basic standards for protection against ionizing radiation and for the safety of radiation sources
GB/T 36416.2 Testing machine vocabulary - Part2 : Non-destructive testing instruments
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 18871 and GB/T 36416.2 and the following apply.
4 Protection requirements for X-ray machines
4.1 Ambient dose equivalent rate caused by leakage radiation from X-ray machines
When the industrial X-ray radiographic equipment below 500kV (hereinafter referred to as “X-ray machine”) is in operation, the main beam window of the X-ray tube shall be covered with a light shield. At the maximum working value specified by the manufacturer, the ambient dose equivalent rate caused by leakage radiation at 100cm from the focal point of the X-ray tube shall be measured with a protective level dosimeter, and the measured results shall meet the requirements in Table 1.
4.2 X-ray tube
4.2.1 The X-ray tube shall be fixable in any required position and locked.
4.2.2 The X-ray tube shall be equipped with a beam limiting device.
4.2.3 The aperture of the X-ray tube window shall be less than or equal to the size required for the emission of the rated maximum useful beam.
4.2.4 The X-ray tube shall be marked with the following:
a) Manufacturer’s name or trademark;
b) Model and serial number;
c) Rated tube voltage and tube power of the X-ray tube;
d) Focal position;
e) Date of manufacture;
f) Ionizing radiation symbol.
4.3 Controller
4.3.1 The controller shall ensure that it cannot be started without permission.
4.3.2 Operation marks related to protective performance shall be clearly indicated.
4.3.3 The controller shall play a safety protection role when the X-ray machine is started.
4.3.4 When the X-ray machine is in operation, the warning yellow light or voice control device configured on the controller shall work normally.
4.3.5 An emergency stop switch shall be provided.
4.3.6 A key switch shall be provided. The X-ray tube can only emit radiation after turning on the console key switch. The key can only be pulled out when the machine is stopped or in standby state.
4.4 X-ray generator
It shall be ensured that the controller can only issue emission instructions when the X-ray generator is connected. When the X-ray generator is disconnected, no X-ray shall be emitted. The connection status of the X-ray generator shall not be changed at will.
4.5 Shielding Material
The thickness of the shielding material inside the X-ray tube shall meet the requirements for the ambient dose equivalent rate caused by leakage radiation in 4.1.
4.6 Connecting Cable
The length of the connecting cable between the controller and the high-voltage generator of the portable X-ray machine shall be greater than or equal to 20m.
4.7 X-ray protection facilities
4.7.1 It shall be ensured that the X-ray generator is disconnected before opening the X-ray protection facilities to prevent the escape of effective X-ray beam radiation. When the X-ray protection facilities are in the protective state, there shall be no leakage radiation of X-rays.
4.7.2 A door-machine interlocking device shall be installed on the protection facilities. When the interlocking device is opened, it shall ensure no voltage output.
5 Protection requirements for X-ray radiographic operation sites
5.1 Protection of X-ray inspection room
5.1.1 The radiographic room shall be separated from the operation room to ensure radiation safety around.
5.1.2 The shielding design of the radiographic room shall ensure that the annual effective dose of operators is less than the corresponding limit. The reference control level of the ambient dose equivalent rate at 30cm outside the shielding body shall be less than or equal to 2.5μSv/h. For the outer surface of the top of the radiographic room where no personnel can reach, the reference control level of the ambient dose equivalent rate at 30cm can usually be 100μSv/h.
Note: The reference contents for the design of the shielding body of the radiographic room include the direction and range of useful beam irradiation, the working load of the device and the outdoor conditions, etc.
5.1.3 The protective performance of the door of the radiographic room shall be the same as that of the wall on the same side. A door-machine interlocking safety device and an irradiation signal indicator shall be installed to ensure that the radiography inspection can be carried out only after the door is closed.
5.1.4 An emergency stop switch shall be equipped in the radiographic room.
5.1.5 A ventilation device shall be equipped in the radiographic room.
5.1.6 A safety protection monitoring device shall be installed in the radiographic room.
5.2 On-site X-ray Radiographic Operation
During on-site radiography inspection, appropriate protective measures shall be taken according to factors such as the distance between the controller and the X-ray tube and the inspected object, irradiation direction, irradiation time and shielding conditions to ensure that the radiation dose of radiographic operators is lower than the dose limit.
6 X-ray protection monitoring during use
6.1 Occupational exposure dose limits
Routine personal dose monitoring shall be carried out for occupational exposure personnel, and personal dose and health management files shall be established. The monitoring values shall meet the requirements of GB 18871, including the following contents:
a) Annual average effective dose for 5 consecutive years;
b) Effective dose in any one year;
c) Annual effective dose to the lens of the eye;
d) Annual equivalent dose to the extremities (hands and feet) or skin.
