Leaks fluorocarbon

Organic fluorine as a separate industry that began in the late 1920s with the discovery by Midgle of fluorocarbons for use as refrigerants. Ammonia was unsuitable because of the hazard and unpleasant smell from minute leaks. Sulfur dioxide had similar problems. The best refrigerant was... 

Passage of CF3OF over a cold-glow electrical discharge (from a vacuum "leak tester" of the Tesla-coil variety) immersed in a metallic vessel caused decomposition into COFj (0.38 mol per mol of CF3OF), Fj, CF, CO3, Oj and fluorocarbons [1649]. 

Surface and transport properties of solvents are very important for solvents. Surface tension of a solvent shows how easy or difficult it would be to wet the surface on which the solvent is being applied. Low surface tension implies better wetting ability and vice versa. Water and other polar organic solvents have very high surface tension, whereas silicones, fluorocarbons, and aliphatic hydrocarbons have low surface tension. Solvents with low surface tension are easier to leak through threaded joints compared to those with high surface tension. 

SPILL CLEAN-UP apply a fluorocarbon water foam to spill to diminish vapor absorb as much as possible with noncombustible materials such as hycar and carbopol materials such as polyester, urethane foam, and seagoing epoxy putty are recommended for plugging leaking containers of methanol remove all ignition sources. 

SPILL CLEAN-UP Collect leaking liquid in sealable containers or absorb in sand or other inert absorbent absorb bulk liquid with fly ash, cement powder, or sawdust, first applying gelling agent to immobilize spill apply fluorocarbon-water foam to diminish vapor. 

All the problems associated with chlorine compression apply to diaphragm compressors. They must be protected against combustion of metal parts in dry chlorine. Since the compressor head usually is carbon steel, this means a maximum temperature of about 120°C. There must be no contact between chlorine and a combustible lubricant. Double separation between the two, as was the case with reciprocating compressors, can prevent this contact. Two diaphragms with an inert intermediate fluid are standard. The oil can be a chlorinated fluorocarbon that does not react with chlorine. The space between diaphragms should have a leak detector that sounds an alarm and shuts down the compressor when either diaphragm fails. 

Significant liquid leaks in fluorocarbon systems may be detected visually. As the material escapes, moisture in the air surrounding the leak condenses and then freezes around the leak due to the refrigerating effect of the vaporizing fluorocarbons. The frost thus formed is readily apparent. 

Electronic leak detectors, which are capable of sensitivities far greater than the other methods-often in terms of fractions of an ounce of fluorocarbon per year. 

A halide torch equipped with a hose through which air is sucked to the flame. The flame will change color when it comes in contact with a leak. This method should not be used with the few fluorocarbon products that are flammable. 

It should be noted that the vapors of these fluorocarbons are all much heavier than air and in the absence of good ventilation will tend to collect in low areas. In handling major leaks, personnel should wear an appropriate SCBA... 

Electronic leak detectors, which are capable of sensitivities far greater than the other methods—often in terms of fractions of an ounce of fluorocarbon per year. When the probe of the instrument is placed near a leak, positive identification of the leak is indicated by a flashing light, by meter deflection, or by audible means. 

Piping may be of copper, preferably Type K, with silver-soldered fittings. ASTM Schedule 40 steel pipe with welded joints may also be used. Screwed fittings, also widely used, exhibit a greater tendency to work loose, resulting in leaks, particularly in areas subject to vibration due to operation of machinery. Polytetrafluoroethylene luting and gaskets are often recommended for fluorocarbon service. 

Bubble/leak testing—utilizing high molecular weight fluorocarbons (tradename Fluorinerts )... 

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