The SF6 quantitative leak detector is a high-precision detection device, mainly used to locate and accurately measure the gas leakage points and leakage rates of electrical equipment that uses SF6 gas as an insulating and arc-extinguishing medium. It also plays a significant role in leakage monitoring and environmental safety control in multiple fields. Relevant detection work must strictly follow the corresponding national and industry standards and regulations.
I. Core Application Areas
(1) Power Industry
The power industry is the core application area of the SF6 quantitative leak detector. All types of high and medium voltage electrical equipment that use SF6 gas as an insulating or arc-extinguishing medium need to be tested for leakage through this device to ensure the safety of equipment operation:
Gas Insulated Switchgear (GIS): As a fully enclosed electrical device, its insulation and arc-extinguishing completely rely on SF6 gas. Even a small leakage can cause a drop in gas pressure, affecting insulation performance and even causing safety accidents. Quantitative leak detection is a key step in the installation, commissioning, and regular maintenance of this equipment.
SF6 Circuit Breakers (GCB): Various types of SF6 circuit breakers, such as tank-type and porcelain column-type, need to maintain the specified SF6 gas pressure and purity. The leak detector is mainly used to detect leakage in the arc-extinguishing chamber and sealing interfaces.
SF6 Insulated Transmission Lines (GIL): Widely used for long-distance and high-capacity power transmission in underground or overhead pipelines, they have extremely high sealing requirements and need regular leakage detection.
SF6 Transformers and Voltage Transformers: Some high-voltage transformers and current/voltage transformers use SF6 gas insulation and need to be tested for leakage through the leak detector.
Gas-filled Switchgear (C-GIS): As a compact switchgear commonly used in distribution networks, it is a regular detection target for the SF6 quantitative leak detector.
(2) Manufacturing Industry
In the manufacturing process of electrical equipment, the SF6 quantitative leak detector is a key quality inspection tool. Before the delivery of equipment such as GIS and circuit breakers that use SF6 gas, strict sealing performance tests must be conducted through this device to confirm that the product’s sealing indicators are qualified. This is an important step in the production process to ensure product quality.
(3) Other SF6 Application Areas
In addition to the power and manufacturing industries, various professional fields that use SF6 gas also need to rely on the SF6 quantitative leak detector for leakage monitoring, taking into account the needs of equipment operation, production processes, and cost control:
Research Institutions: Some physical experiment devices (such as particle accelerators) use SF6 as an insulating medium and need to detect SF6 leakage in the equipment and pipelines.
Metallurgical Industry: In the process of magnesium alloy smelting, SF6 is used as a protective gas, and the leakage of SF6 in the production environment needs to be monitored to ensure the safety of on-site workers and effectively control the cost of gas usage.
Semiconductor Manufacturing: In the chip etching process, SF6 is a commonly used plasma gas, and leakage detection in the process chamber and delivery pipelines is necessary to ensure process stability.
(4) Environmental Protection and Safety Field
The characteristics of SF6 gas determine that its leakage detection has both environmental protection and safety significance. The SF6 quantitative leak detector is an important technical means to implement relevant control requirements:
Compliance with International Conventions: SF6 is a potent greenhouse gas explicitly controlled by the Kyoto Protocol and the Paris Agreement, with a global warming potential (GWP) more than 23,500 times that of CO2. Quantitative leak detection for SF6 leakage monitoring and control is a necessary measure for relevant enterprises to fulfill their emission reduction responsibilities and conduct carbon accounting.
Occupational Health and Safety: In enclosed spaces such as underground substations and cable tunnels, SF6 itself is non-toxic, but large-scale leakage can displace oxygen in the air, posing a risk of suffocation to personnel. At the same time, the arc decomposition products of SF6 (such as low fluorides) are toxic. Quantitative leak detection must be carried out in a timely manner to detect and handle leaks, and prevent safety accidents.
II. Relevant Standards and Procedures for SF6 Leak Detection
When conducting SF6 leak detection work, it is necessary to follow the relevant national and power industry standards and procedures to ensure the accuracy and comparability of the detection results, as well as the safety of the operation process. The core standards in the Chinese power industry mainly fall into the following three categories:
(1) Core Basic Standards
GB/T 11023 “Sealing of SF6 for High-Voltage Switchgear and Controlgear” is the most direct and important basic standard for SF6 leak detection. This standard clearly defines the core detection requirements and norms:
It defines the leakage rate and specifies the calculation method for the leakage rate;
It stipulates the allowable SF6 leakage rate standards for different equipment, such as the annual leakage rate of a single closed pressure system, which should not exceed 0.5% or 0.1% depending on the equipment type and voltage level;
It provides detailed explanations of various detection methods for qualitative and quantitative leak detection, including the hood method (overall accumulation method), the bottle hanging method (local accumulation method), the pressure drop method, as well as the infrared laser absorption method and negative ion capture method, which are the mainstream methods used in modern quantitative leak detectors;
It sets clear and specific requirements for the instruments and equipment used in detection, the detection environment conditions, and the specific operation steps.
(2) Standards for Installation and Operation Maintenance of Equipment
DL/T 603 “Operation and Maintenance Regulations for Gas-Insulated Metal-Enclosed Switchgear”: It clearly stipulates the SF6 gas leakage detection cycle and specific requirements for gas-insulated metal-enclosed switchgear before commissioning, after major overhauls, and during daily operation. It also formulates response measures for leakage discovery and gas pressure reduction.
GB 50150 “Code for Handover Tests of Electrical Installations”: In the relevant chapters on SF6 circuit breakers and gas-insulated metal-enclosed switchgear, it clearly requires that a sealing test must be conducted during the handover test stage after equipment installation, and the leakage rate index must comply with both the product technical specifications and GB/T 11023.
(3) Safety and Environmental Protection Standards
DL/T 639 “Safety Protection Details for Operation, Testing and Maintenance Personnel of SF6 Electrical Equipment”: Although this standard focuses on personnel safety protection and SF6 gas treatment, it also clearly defines the safety operation matters during SF6 detection and gas replenishment, especially the specific requirements for handling arc decomposition products after detecting a leak.
Relevant enterprise standards of power grid enterprises: Such as “State Grid Corporation of China Electric Power Safety Work Regulations (Substation Section)” and other enterprise standards, incorporate SF6 electrical equipment leak detection work into the safety management system for SF6 equipment operation and maintenance, and clearly define the safety operation norms and requirements for leak detection operations.
Post time: Jan-23-2026