Product Description
Sulfur hexafluoride is a colorless, odorless, nonflammable, non-reactive, relatively non-toxic, asphyxiating only liquefied gas. Bottled liquefied gas under its own vapor pressure (202.78 kgf / cm2 @ 21.1 ° C). Sulfur hexafluoride its good insulating properties and arc performance, are widely used in the electrical industry, such as: circuit breakers, high voltage switch, high voltage transformers, gas closed composite capacitors, high voltage transmission lines, transformers and other. SF6 also because chemically inert, non-toxic, non-flammable and non-corrosive, is also widely used in metal smelting (such as magnesium alloy melting furnace protective gas), aerospace, medical (X-ray machines, laser machines), weather (tracer analysis), chemical (senior automotive tires, the new fire extinguishers), etc. Electronic grade high purity sulfur hexafluoride is an ideal electronic etchant, is widely used in microelectronics technology. With today's technology, the field of SF6 involved continues to expand, more and more areas of the field of basic science and technology widely used in the refrigeration industry, with sulfur hexafluoride do refrigerants, refrigeration range at -45 ℃ ~ between 0 ℃.

 

The use of sulfur hexafluoride gas sulfur hexafluoride circuit breaker is used as a circuit breaker media and insulating medium. Sulfur hexafluoride gas is used as a circuit breaker interrupter media began in the early 1950s. Due to the excellent properties of sulfur hexafluoride gas, so that sulfur hexafluoride single break breaker in terms of voltage and current parameters much higher than the air circuit breaker and less oil circuit breakers, and does not require high pressure and a considerable number of series-off port number. In 60 to 70 years, SF6 circuit breakers have been widely used in EHV bulk power system. Early 1980s, has been successfully developed 363 kV single fracture, 550 kV double fracture and rated breaking current of up to 80,100 kA SF6 circuit breakers.

 

Sulfur hexafluoride application
Used as sulfur hexafluoride circuit breakers, mutual conductance sensor, lightning arcing sulfur hexafluoride gas
Die-cast magnesium alloy is used as a protective gas in
High-purity electronic grade sulfur hexafluoride as an ideal electronic etching gas, widely used in the field of microelectronics
As a single optical fiber manufacturing fiber membrane isolation layer dopant
As pollution monitoring and hydrogeological testing field of atmospheric tracers
Liver tumors CEUS as sulfur hexafluoride contrast agent also uses

 

Precautions
Sulfur hexafluoride should be stored in a cool, ventilated warehouse. Away from fire and heat. Storage temperature should not exceed 50 ℃. Should be easy (to) fuel materials, oxidizers stored separately to avoid mixing reservoir. Storage areas should be equipped with spill response equipment. Closed operation, local exhaust ventilation. The operator must go through specialized training, strict adherence to rules. Proposed operators wear filter respirators (half-mask). Away from flammable and combustible materials. Prevent gas leakage into the workplace air. Avoid contact with oxidizing agents. When moving gently, to prevent damage cylinders and accessories. Equipped with spill response equipment. Bottled gas products for high-pressure filling gas, should be used by decompression buck before use. Life on the packaging of cylinders are used, where the expired gas cylinders must be taken to have a safety inspection department before they can continue to use. Bottle when using the exhaust gas, and pressure in the bottle should be kept 0.5MPa, more than the minimum of not less than 0.25MPa pressure cylinder valve should be closed to ensure the gas quality and safe to use. Bottled gas products in the transport and storage, the use of classification should be stacked, non-combustible gas and combustion gas stacked together, are not allowed near open flames and heat sources, do not get near the fire should be, not contaminated with oil wax, not prolonged sun exposure, not weight throw Do not hit, were prohibited in the cylinder body arc or arc, rough handling is strictly prohibited.

 

Physicochemical properties of sulfur hexafluoride
Molecular Weight: 146.054
Melting point (224kPa): -50.8 ℃
Liters of points (101.325kPa): -63.7 ℃
Liquid density (-50.8 ℃): 1880kg / m3
Gas density (0 ℃, 101.325kPa): 6.52kg / m3
The relative density (gas, air = 1,20 ℃, 101.325kPa): 5.114
Hematocrit (21.1 ℃, 101.325kPa): 0.1516m3 / kg
Critical temperature: 45.5 ℃
Critical pressure: 3759kPa
Critical Density: 736kg / m3
Compression factor

温度	压缩系数
	100kPa	1000kPa	2000kPa	3000kPa
15	0.9886	0.8656
50	0.9926	0.9137	0.8113	0.6760

Heat of fusion (222.35K, 224kPa): 34.38kJ / kg
Heat of vaporization (-63.8 ℃, 101.325kPa): 161.61kJ / kg
Specific heat capacity (gas, 25 ℃, 101.325kPa): CP = 665.18J / (kg · K)
(Liquid, 225K): C = 759.14J / (kg · K)
Vapor pressure (-20 ℃): 680kpa.
(0 ℃): 1250kPa
(30 ℃): 2680kPa
Viscosity (101.325kPa, 0 ℃): 0.0142mPa · S
(Liquid, 229.85K): 0.500mPa · S
Surface tension (-50 ℃): 11.63mN / m
Thermal conductivity (101.325kPa, 0 ℃): 0.01206W / (m · K)
Refractive index (gas, 0 ℃, 101.325kPa): 1.000783

 

Sulfur hexafluoride at normal temperature and pressure is a colorless, odorless toxic gas. Do not burn. The thermal stability, chemical properties and lively. At above 500 ℃ red hot state is not decomposed, at below 800 ℃ very stable. At 250 ℃ reaction with sodium metal. No corrosion, you can use common materials, non-corrosive glass. Electrical insulation properties and arc extinguishing property, 2 to 3 times the insulation performance of the air, and the greater the gas pressure, the insulation performance increases. Properties of the drug inactive, not toxic. Slightly soluble in water, alcohol and ether, and more than that dissolved in the water some. Insoluble in hydrochloric acid and ammonia. Water solubility: 5.4cm3SF4 / kgH2O (SF6 partial pressure 101.325kPa, 25 ℃). Dielectric constant: 1002049 (gas, 101.325kPa, 25 ℃). When 21.1 ℃ S.P. for 2308kPa.