SF₆-Free GIS Adoption Creates New Demand for C4-FN Gas Handling and Testing Equipment
Global Shift Toward SF₆-Free Switchgear Accelerates
The power transmission industry is entering a new era of environmentally friendly insulation technologies.
In recent years, leading manufacturers including Hitachi Energy, Siemens Energy, GE Vernova, and Mitsubishi Electric have accelerated the development of SF₆-free high-voltage switchgear and circuit breakers. Among the latest milestones are Hitachi Energy’s successful deployment of the world’s first 550 kV SF₆-free GIS project and the introduction of its 800 kV SF₆-free circuit breaker platform under the EconiQ™ portfolio.
These developments demonstrate that alternative insulation gas technologies are rapidly moving from research and pilot projects into commercial power grid applications.
C4-FN Mixed Gas Technology Gains Industry Acceptance
Many next-generation environmentally friendly GIS and circuit breakers are based on gas mixtures containing fluoronitrile (C4-FN), carbon dioxide (CO₂), and oxygen (O₂).
These gas mixtures provide significantly lower global warming potential (GWP) compared with conventional SF₆ while maintaining the compact design and high-performance characteristics required for modern high-voltage substations.
As utilities begin deploying both traditional SF₆ equipment and new environmentally friendly switchgear, gas management requirements are becoming increasingly complex.
New Challenges Beyond the Switchgear Itself
While industry attention is often focused on the switchgear and circuit breaker technologies, the transition to C4-FN-based insulation systems also creates new requirements for:
- Gas identification
- Gas composition analysis
- Moisture measurement
- Gas quality verification
- Leak detection
- Gas recovery and recycling
- Commissioning and maintenance operations
Accurate gas testing is essential to ensure insulation performance, equipment reliability, and compliance with manufacturer specifications.
KSTONE Provides a Complete C4-FN Gas Management Solution
To support the growing adoption of C4-FN-based environmentally friendly switchgear, Shanghai Yushi Technology Development Co., Ltd. (KSTONE) has developed a complete portfolio of gas testing, gas mixing, leak detection, and gas recovery equipment for next-generation insulation gas technologies.
Unlike traditional SF₆ service equipment suppliers, KSTONE now offers dedicated solutions covering the entire lifecycle of C4-FN mixed gas applications.
C4F7N Gas Analysis and Quality Verification
KSTONE provides several dedicated analyzers for environmentally friendly gas-insulated equipment:
• KS30-C4 C4F7N Gas Mixture Analyzer
Capable of measuring C4F7N, CO₂, O₂, SF₆ and N₂ concentrations while simultaneously performing moisture and gas purity analysis.
• KS31-C4-4 C4F7N Comprehensive Tester
An all-in-one testing platform integrating gas composition analysis, moisture measurement, and gas quality evaluation for environmentally friendly switchgear applications.
C4F7N Gas Mixing Equipment
To support gas preparation and filling operations, KSTONE also provides dedicated gas mixing systems.
• KSC4-C4-CO2-O2 Gas Mixing Unit
Designed for accurate preparation of C4F7N / CO₂ / O₂ mixed gases, with adjustable C4 concentration ratios suitable for environmentally friendly GIS and circuit breaker applications.
C4F7N Leak Detection Solutions
As utilities deploy larger numbers of environmentally friendly substations, gas leak monitoring becomes increasingly important.
• LF-300-C4 Quantitative Leak Detector
High-sensitivity leak detection equipment specifically designed for C4F7N applications, capable of detecting extremely low gas leakage concentrations.
C4F7N Gas Recovery and Recycling Equipment
Environmental gases are valuable and should be recovered whenever possible during maintenance and overhaul operations.
• KSC4-30WY/20-400Z High-Pressure C4F7N Recovery System
Designed for 110 kV to 550 kV GIS applications, supporting gas recovery, storage, vacuum pumping, purification, and refilling operations.
The system enables utilities and service companies to safely recover and reuse environmentally friendly insulation gases while reducing operating costs and minimizing environmental impact.
One Supplier for Both SF₆ and C4-FN Technologies
As conventional SF₆ equipment and environmentally friendly switchgear will coexist for many years, utilities increasingly require testing and handling solutions capable of supporting multiple insulation gas technologies.
KSTONE’s portfolio now covers:
• SF₆ gas analysis
• SF₆/N₂ gas ratio analysis
• SF₆/CF₄ gas ratio analysis
• C4F7N gas analysis
• C4F7N gas mixing
• C4F7N leak detection
• C4F7N gas recovery
• Moisture measurement
• Gas handling and recycling
This comprehensive product range enables utilities, GIS manufacturers, EPC contractors, and commissioning teams to manage both traditional and next-generation gas-insulated equipment from a single equipment supplier.
Supporting the Future of High-Voltage Gas Technologies
The global transition from SF₆ to environmentally friendly insulation gases is creating new opportunities and technical challenges throughout the power industry.
As conventional SF₆ equipment and alternative gas technologies continue to coexist for decades to come, KSTONE remains committed to providing complete gas testing and gas handling solutions for utilities, GIS manufacturers, service companies, and commissioning teams worldwide.