Leaks are detected by a leak-detecting halide torch (see Fig. 5-6). Some torches use alcohol for fuel and produce a colorless flange. When a methyl chloride leak is detected, the flame turns green. A brilliant blue flame is produced when large or stronger concentrations are present. In every instance, the room should be well ventilated …
Read More…Category: Refrigerants
Detecting Ammonia Leak
Leaks are detected (in small amounts of ammonia) when a lit sulfur candle is used. The candle will give off a very thick, white smoke when it contacts the ammonia leak. The use of phenolphthalein paper is also considered a good test. The smallest trace of ammonia will cause the moistened paper strip to turn …
Read More…Detecting Carbon Dioxide Leak
Leaks can be detected with a soap solution if there is internal pressure on the part to be tested. When carbon dioxide is present in the condenser water, the water will turn yellow with the addition of bromothymol blue.
Read More…Detecting Sulfur Dioxide Leak
To detect sulfur dioxide leaks, an ammonia swab may be used. The swab is made by soaking a sponge or cloth tied onto a stick or piece of wire in aqua ammonia. Household ammonia may also be used. A dense white smoke forms when the ammonia comes in contact with the sulfur dioxide. The usual …
Read More…Freon Reaction to Plastics
A brief summary of the effect of Freon compounds on various plastic materials follows. However, compatibility should be tested for specific applications. Differences in polymer structure and molecular weight, plasticizers, temperature, and pressure may alter the resistance of the plastic toward the Freon compound. Teflon TFE-fluorocarbon resin: No swelling observed when submerged in Freon liquids, …
Read More…Freon Reaction to Metal
Most of the commonly used construction metals, such as steel, cast iron, brass, copper, tin, lead, and aluminum, can be used satisfactorily with the Freon compounds under normal conditions of use. At high temperatures some of the metals may act as catalysts for the breakdown of the compound. The tendency of metals to promote thermal …
Read More…Ethyl Chloride Refrigerants
Ethyl chloride (C2H5Cl) is not commonly used in domestic refrigeration units. It is similar to methyl chloride in many ways. It has a boiling point of 55.6°F (13.1°C) at atmospheric pressure. Critical temperature is 360.5°F (182.5°C) at a pressure of 784 lb absolute. It is a colorless liquid or gas with a pungent ethereal odor …
Read More…Calcium Chloride Refrigerants
Calcium chloride (CaCl2) is used only in commercial refrigeration plants. Calcium chloride is used as a simple carrying medium for refrigeration. Brine systems are used in large installations where there is danger of leakage. They are used also where the temperature fluctuates in the space to be refrigerated. Brine is cooled down by the direct …
Read More…Carbon Dioxide Refrigerants
Carbon dioxide (CO2) is a colorless gas at ordinary temperatures. It has a slight odor and an acid taste. Carbon dioxide is nonexplosive and nonflammable. It has a boiling point of 5°F (?15°C). Apressure of over 300 psi is required to keep it from evaporation. To liquefy the gas, a condenser temperature of 80°F (26.6°C) …
Read More…Ammonia Refrigerants
Ammonia (NH3) is used most frequently in large industrial plants. Freezers for packing houses usually employ ammonia as a refrigerant. It is a gas with a very noticeable odor. Even a small leak can be detected with the nose. Its boiling point at normal atmospheric pressure is ?28°F (?33°C). Its freezing point is ?107.86°F (?77.7°C). …
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