Fully sealed, all-insulated determines the high degree of adaptability to the environment. High-voltage switches, moving parts are sealed in the box made of SF⁶gas that made of welded stainless steel plate(≥2.5mm). Switch casing and the shaft bearings are used switch to ensure the sealing special gas box of tightness. High-pressure welding wire sealing in sealed cabin that made up of silicone rubber and epoxy resin. Cable sealing in silicon rubber cable accessories. Silicon rubber cable accessories and welding wire tanks are 1000 hours of salt spray test.