Corrosion in Gas-Insulated Switchgear and Circuit Breakers with Respect to Gas Leakage: Causes, Prevention, Lifecycle Impact, Field Experience, Laboratory Studies, and Recommendations

Gas leakage from gas‑insulated switchgear (GIS), gas‑insulated lines (GIL), hybrid GIS, and air‑insulated switchgear (AIS) circuit breakers has become a significant reliability and environmental concern, with failures occurring as early as five to seven years after commissioning. Root‑cause investigations attribute these premature leaks to corrosion driven by harsh outdoor environments. This paper characterises the corrosion mechanisms responsible for early leakage, evaluates their severity through field observations and laboratory testing, and proposes effective mitigation strategies for future and existing assets.