Sulfur Hexafluoride Gas (SF6) Properties

Sulfur Hexafluoride Gas (SF6) Properties

• Heavy, chemically inert, non toxic
• No poisonous effect on the human body but decomposition products are poisonous
• Color less and odor less
• It is gaseous at normal room temperature and pressure
• Density is about 6.6g/l at 20^oC (5 times denser than air)
• Critical temperature is at 45.6^oC and can be liquefied by compression
• Very good insulant with high dielectric strength
• SF6 gas is electo-negitive ( tends to attract the free electrons and has the arc quenching property). Because of this main reason SF6 gas is used for arc quenching and insulation medium in circuit breakers.
• The gas is highly stable
• Unlike solid insulation materials, electrical breakdown of sf6 gas does not result in permanent deterioration of its properties.
• Decomposition occurs on the exposure to the electric arc. (Disassociation products will be SF2 and SF4 lower order fluorides)