C4F7N Gas Standards Meeting Highlights Growing Momentum for SF₆ Alternative Technologies
On April 13, 2026, the first working meeting for two industry group standards related to C4F7N (Perfluoroisobutyronitrile) environmentally friendly gas technologies was officially held in China.
The two standards focus on:
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Technical requirements for C4F7N environmentally friendly gas
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Technical requirements for C4F7N gas synthesis and preparation processes
Before the meeting, Shanghai KSTONE was invited to participate in the preliminary drafting and editing of the standard documents. Following the meeting, the company also submitted formal written feedback and technical recommendations regarding both standards.
This participation reflects the industry’s increasing attention toward C4F7N as one of the most promising alternatives to Sulfur Hexafluoride in high-voltage power applications.
Why C4F7N Is Gaining Attention as an SF₆ Alternative
| Comparison Item | SF₆ | C4F₇N |
|---|---|---|
| Global Warming Potential (GWP, 100-year) | 23500 | 1 |
| Dielectric Insulation Strength | 100% (Baseline) | ~98% of SF₆ |
| Atmospheric Lifetime | Extremely long | Short |
| Environmental Impact | Strong greenhouse gas | Eco-friendly low-carbon alternative |
| Insulation Performance | Excellent | Nearly equivalent to SF₆ |
| Application | Traditional GIS, switchgear, transformer | SF₆ replacement for eco-friendly high-voltage equipment |
| Carbon Footprint | Very high | Very low |
Perfluoroisobutyronitrile is currently regarded as one of the most advanced next-generation insulating gases for medium- and high-voltage electrical equipment.
Compared with traditional SF₆ gas, C4F7N offers significant environmental advantages while maintaining strong dielectric performance.
Key Advantages of C4F7N
Low Global Warming Potential (GWP)
One of the biggest concerns surrounding SF₆ gas is its extremely high global warming potential.
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SF₆ GWP: approximately 23,500
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C4F7N GWP: approximately 1/10 of SF₆
In addition, C4F7N has a much shorter atmospheric lifetime, making it more aligned with global carbon reduction and environmental protection policies.
High Insulation Performance
C4F7N demonstrates excellent dielectric strength.
Its insulation capability is approximately:
2.2 times higher than SF₆
This makes the gas particularly attractive for:
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GIS equipment
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GIL systems
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Medium-voltage switchgear
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High-voltage power transmission applications
As of May 2026, C4F7N-based technologies have already progressed from demonstration projects to practical engineering deployment, including successful operation in 550kV ultra-high-voltage GIL systems.
Technical Challenges of C4F7N Applications
Although C4F7N has strong potential, several engineering challenges still need to be addressed before large-scale adoption.
Low-Temperature Liquefaction
C4F7N has a boiling point of approximately:
-4.7°C
To improve low-temperature performance, the gas is commonly mixed with CO₂ or other gases.
The most widely used solution today is:
C4F7N / CO₂ mixed gas systems
Arc-Quenching Optimization
While C4F7N provides excellent insulation strength, its arc-extinguishing capability is slightly weaker than SF₆.
Optimized gas mixing ratios and equipment design are therefore essential for stable switching performance.
Material Compatibility and Gas Handling
Practical deployment also requires solutions for:
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Material compatibility
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Gas mixing accuracy
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Filling systems
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Recovery and purification technologies
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Leakage monitoring
These areas are becoming key focuses for both equipment manufacturers and standards organizations.
Shanghai KSTONE Expands C4F7N Equipment Capabilities
Shanghai KSTONE has already established full delivery capability for C4F7N gas handling and testing equipment.
In January 2026, the company completed delivery of a complete C4F7N mixed-gas equipment package, including:
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C4F7N gas leak detector
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Gas mixing ratio analyzer
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Mixed-gas filling device
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Gas recovery, separation and purification system
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Mixed-gas storage tanks
These systems are designed for environmentally friendly gas applications in GIS and high-voltage power equipment.
Participation in C4F7N Standards Development
Shanghai KSTONE’s participation in the April 2026 standards meeting represents a continuation of its involvement in environmentally friendly gas technology standardization work.
The company also participated in the development of the already released industry standard:
T/CEC 1092-2025
Technical Specification for Perfluoroisobutyronitrile Mixed Gas Refilling Devices
As global utilities and switchgear manufacturers accelerate the transition away from SF₆, standardization of C4F7N gas technologies is expected to become increasingly important for future GIS and GIL applications.