Sulfur hexafluoride gas (SF6) properties are given below
- SF6 gas is Heavy, chemically inert, non-toxic
- SF6 gas has no poisonous effect on the human body but decomposition products are poisonous
- SF6 gas is Colourless and odourless
- It is gaseous at normal room temperature and pressure
- Density is about 6.6g/l at 20°C (5 times denser than air)
- Critical temperature is at 45.6°C and can be liquefied by compression
- Very good insulant with high dielectric strength
- SF6 gas is electronegative ( 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).
