How does the self-sealing valve effectively prevent SF6 gas leakage and ensure the safe operation of medium and high voltage electrical equipment?
Publish Time: 2025-04-29
In modern power systems, sulfur hexafluoride (SF6) gas is widely used in medium and high voltage electrical equipment, such as circuit breakers, disconnectors, GIS combination electrical appliances, etc., due to its excellent insulation performance and arc extinguishing ability. However, SF6 gas is not only expensive, but also a potent greenhouse gas. If it leaks, it will not only affect the normal operation of the equipment, but also have a serious impact on the environment. Therefore, in SF6 gas-related equipment, self-sealing valve, as a key connection device, is playing an increasingly important role.1. Basic structure and working principle of self-sealing valveSelf-sealing valve is essentially an airtight connection device with "automatic closing" function. Its core components include valve body, valve core, spring and sealing ring. When the connector is inserted, the valve core is pushed open to open the gas channel; when the connector is pulled out, the internal spring quickly resets, pressing the valve core against the valve seat, and completely closing it through a highly elastic sealing ring to prevent gas leakage.This design enables the self-sealing valve to achieve automatic control of "connecting ventilation and unplugging sealing" without manual intervention or additional operation during the plugging and unplugging process, greatly improving the safety and efficiency of use.2. The role of self-sealing valve in preventing SF6 gas leakageInstant sealing, eliminating the source of leakage: In traditional valve systems, when disassembling equipment, it is often necessary to manually close the valve and block the interface. This process has the risk of human operation errors and is prone to gas leakage. The self-sealing valve can complete the sealing action immediately when the connector is unplugged, fundamentally eliminating the occurrence of leakage points.Suitable for frequent operation scenarios: In the maintenance and repair of substations, it is often necessary to connect gas detectors, charging and discharging equipment and other tools. The self-sealing valve supports quick plugging and unplugging, is easy to operate, and can automatically restore the sealing state after each plugging and unplugging, which is very suitable for such high-frequency operation environments.Improve the overall airtightness of the equipment: SF6 electrical equipment has extremely high requirements for its sealing. As an important node in the gas circuit, the high-quality sealing performance of the self-sealing valve helps maintain the stable gas pressure of the entire system and avoid insulation degradation or even failure shutdown caused by local leakage.3. The key role of ensuring the safe operation of medium and high voltage electrical equipmentMaintaining the insulation performance of equipment: SF6 gas is the core insulating medium of many medium and high voltage equipment. Once a leak occurs, the gas concentration inside the equipment decreases, the insulation strength decreases, and serious accidents such as arcing and breakdown may occur. The effective sealing function of the self-sealing valve can ensure that the equipment is always in a good gas environment and ensure its long-term stable operation.Reduce the risk of power outages and maintenance costs: Because the self-sealing valve can avoid gas leakage to a great extent, it reduces unplanned shutdowns caused by insufficient gas. At the same time, it also reduces the subsequent gas replenishment frequency and detection and maintenance costs, and improves the overall economy of the equipment.Enhance the safety of on-site operations: Although SF6 gas itself is non-toxic, it will decompose under the action of high-temperature arcs to produce toxic byproducts (such as HF, SO2, etc.), which pose a threat to human health. The use of self-sealing valve can effectively prevent the accidental release of gas during operation and improve the safety factor of on-site personnel operations.In summary, the self-sealing valve plays an irreplaceable role in preventing SF6 gas leakage and ensuring the safe operation of medium and high voltage electrical equipment with its unique automatic sealing mechanism. It not only improves the reliability and safety of the system, but also shows great advantages in energy saving and environmental protection, and reducing operation and maintenance costs.
