SF6 Vacuum Evacuation Units for GIS & High-Voltage Equipment
YUNENG SF6 Evacuation Units are engineered for rapid and deep vacuuming of electrical equipment. This high-performance system efficiently removes air and moisture, ensuring the high-vacuum environment required for SF6 gas refilling and long-term dielectric stability.
Key Features:
- High-Speed Evacuation: Equipped with premium vacuum pumps for rapid pull-down and high ultimate vacuum levels.
- Portable & Agile: Compact, mobile design optimized for easy maneuverability in substations and job sites.
- Stable Operation: Features integrated protection and precise monitoring instruments for safe, long-term service.
Our SF6 Evacuation Unit Range
What Is an SF6 Evacuation Unit?
An SF6 evacuation unit is designed to create a deep vacuum inside gas-insulated electrical equipment before SF6 gas filling or maintenance. By removing air, moisture, and non-condensable gases, the unit prepares the internal chamber for high-purity SF6 insulation, helping maintain stable dielectric performance and reducing the risk of partial discharge.
Unlike general-purpose vacuum pumps, an SF6 evacuation unit is engineered for high-voltage equipment, featuring vacuum gauges, durable piping, and reliable sealing components that ensure safe operation during commissioning and servicing. It is widely used in substations, GIS manufacturing plants, transformer factories, and electrical maintenance projects where vacuum preparation is an essential step before equipment is returned to service.
How the SF6 Evacuation Process Works
A standard SF6 evacuation procedure follows a systematic sequence to ensure equipment is completely prepared for gas filling.
| Step | Description |
| 1. Connect Equipment | Securely connect the evacuation hoses to the GIS, circuit breaker, or gas-insulated equipment. |
| 2. Start Vacuum Pumping | Activate the vacuum pump to remove air and residual gases from the enclosure. |
| 3. Remove Moisture | Continue evacuation until moisture and contaminants are extracted to the required level. |
| 4. Vacuum Holding Test | Maintain the vacuum for a specified period to verify system tightness and identify potential leaks. |
| 5. SF6 Gas Filling | After passing the vacuum test, the equipment is ready for safe SF6 gas charging. |
Why Deep Vacuum Is Important Before SF6 Filling
Creating a deep vacuum before filling SF6 gas is a critical step in ensuring the electrical performance and service life of gas-insulated equipment.
- Eliminate Residual Air: Residual air reduces the concentration of SF6 gas and weakens insulation performance. Proper evacuation removes trapped air, allowing the equipment to operate with optimal dielectric strength.
- Reduce Internal Moisture: Moisture can lower insulation resistance and contribute to the formation of harmful by-products during operation. Deep vacuum effectively removes water vapor before gas charging.
- Improve Gas Quality: A clean internal environment allows fresh SF6 gas to maintain its designed purity, helping achieve stable electrical characteristics throughout the equipment’s operating life.
- Increase System Reliability: Proper vacuum preparation minimizes the possibility of insulation failure, unexpected shutdowns, and costly maintenance, ensuring dependable operation in high-voltage applications.
Typical Applications of SF6 Evacuation Unit
SF6 evacuation units are widely used throughout the power industry to prepare gas-insulated equipment for commissioning, maintenance, and manufacturing. By creating a clean, moisture-free vacuum environment before SF6 filling, they help improve insulation reliability, operational safety, and long-term equipment performance across a wide range of high-voltage applications.
Gas-Insulated Switchgear
Creates the required vacuum inside GIS compartments before SF6 filling, ensuring clean insulation conditions and reliable system commissioning.
Gas-Insulated Transmission Lines
Removes moisture and residual gases from enclosed transmission pipelines before gas charging, supporting stable insulation performance over long distances.
High-Voltage Circuit Breakers
Prepares breaker chambers for maintenance or factory testing by establishing a deep vacuum prior to SF6 refilling.
Electrical Equipment Manufacturing
Supports production lines by performing vacuum preparation during assembly, factory acceptance testing, and final quality inspection.
Utility Substations
Used during equipment installation, scheduled maintenance, and gas replacement projects to ensure safe and efficient servicing.
Renewable Energy Power Facilities
Provides vacuum preparation for GIS equipment installed in wind farms, solar substations, and other renewable energy grid connection projects.
Need a Customized SF6 Evacuation Solution?
Tell us your equipment type and project requirements. Our engineers will recommend the most suitable model with professional technical support.
How to Choose the Right SF6 Evacuation Unit
Selecting the right SF6 evacuation unit depends on the type of equipment, project requirements, and maintenance frequency. Evaluating the following factors helps ensure efficient operation and long-term reliability.
| Selection Factor | What to Consider |
| Equipment Volume | Larger GIS systems require higher pumping speeds to reduce evacuation time. |
| Ultimate Vacuum | A lower ultimate pressure provides more complete removal of air and moisture. |
| Vacuum Pump Capacity | Choose an appropriate pumping rate based on the size and quantity of equipment to be serviced. |
| Mobility Requirements | Portable units are ideal for field maintenance, while stationary systems suit factory production lines. |
| Measurement Accuracy | High-precision vacuum gauges help monitor evacuation performance throughout the process. |
| Operating Environment | Select equipment designed for continuous operation under demanding industrial conditions. |
Choosing a properly sized evacuation unit improves work efficiency, shortens maintenance time, and helps achieve consistent vacuum performance across different applications.
SF6 Evacuation Unit vs. SF6 Recovery Unit
Although both systems are used in SF6 gas handling, they serve different purposes during equipment maintenance.
| Feature | SF6 Evacuation Unit | SF6 Recovery Unit |
| Primary Function | Create a deep vacuum before gas filling | Recover, purify, store, and refill SF6 gas |
| Air & Moisture Removal | ✔ | ✔ |
| SF6 Gas Recovery | ✖ | ✔ |
| Gas Storage Cylinders | ✖ | ✔ |
| Gas Purification | ✖ | ✔ |
| Gas Refilling | ✖ | ✔ |
| Typical Application | Equipment commissioning and vacuum preparation | Complete SF6 maintenance and gas recycling |
If the primary objective is to prepare equipment before filling new SF6 gas, an evacuation unit provides an efficient solution. For projects involving gas recovery, purification, storage, and reuse, a complete SF6 recovery unit is the preferred choice.
Why Choose YUNENG SF6 Evacuation Units?
With decades of experience in oil purification and gas handling equipment, YUNENG delivers dependable SF6 evacuation solutions for utilities, equipment manufacturers, and electrical service companies worldwide.
Proven Manufacturing Experience
29+ years of engineering expertise; every unit is designed for reliable performance in demanding industrial environments.
Strict Quality Control
Each machine undergoes comprehensive inspection and functional testing before delivery to ensure consistent product quality
Customized Solutions
Equipment configurations can be tailored to meet different voltage classes, project requirements, and customer specifications.
Reliable Global Supply
Efficient production management and export experience enable fast delivery to customers in markets around the world.
Comprehensive Technical Support
Professional engineers provide installation guidance, operation training, troubleshooting assistance, and responsive after-sales service.
Long-Term Value
Durable components, practical designs, and easy maintenance help reduce lifecycle costs and maximize equipment availability.