Why is sulfur hexafluoride a good insulator?

This leads to it having excellent dielectric properties; indeed the dielectric strength of sulfur hexafluoride gas is about 2.5 times more than that of air. SF6 has therefore been used as an insulating material in electrical systems, as a circuit breaker, in high voltage switch gear and as an arc-quenching medium.

Does sulphur hexafluoride have a breakdown voltage?

The breakdown voltage of SF 6 reaches that of transformer oil at a pressure of only 3 bar (Fig. 25). The behaviour of sulphur hexafluoride conforms over a wide range of pressures to Paschen‘s Law: at higher pressures, however, deviations have been observed under certain conditions [5,6,7].

Why is sulphur hexafluoride used in Transformers?

Its excellent heat-transfer capacity, non-flammability and non-toxicity have also promoted the use of sulphur hexafluoride in the construction of transformers. On account of their high operational safe-ty, SF6-gas transformers are installed in mines and department stores.

Is sulphur hexafluoride safe?

Changing from conven-tional dielectrics to sulphur hexafluoride – a non-flammable, chemically-inactive and non-toxic heavy gas – results in consider-able space and weight savings and im -provements in the operational safety of converted equipment.

How is sulphur hexafluoride shipped?

Solvay sulphur hexafluoride is shipped as a pressure-liquefied gas in steel cylinders of various sizes. The filling level of SF6 per li-tre of packaging volume can vary between 1.06 kg and 1.38 kg (depending on the test pressure of the packaging). SF6 is supplied in steel cylinders of 5, 10, 20, 40, 43.5 and 600 l capacity (Fig. 42).

When was sulphur hexafluoride made?

Sulphur hexafluoride was first synthesised in the laboratories of the Faculté de Pharmacie de Paris in 1900 by Moissan and Lebeau. Fluorine, obtained by electrolysis, was allowed to react with sulphur and a strongly exothermic reaction, giving rise to a remarkably stable gas.