R-22 is a m an-made refrigerant developed for refrigeration installations that need a low evaporating temperature. One application is in fast freezing unit which maintain a temperature of -200F to -400F (-29 to -400C). It has also been successfully used in air conditioning units and in house hold refrigerators. It is used with both reciprocating and centrifugal compressors.
R-22 has a boiling point of -41 degree F at atmosphere pressure. it is stable and in nontoxic non corrosive nonirritating and nonflammable. The evaporator pressure of R-22 is 43 psi or 28 psi (1.96 kg/cm2) at d degree F. The cylinder code color is green.
The principal advantage of Refrigerant - 22 over Refrigerant -12 is the smaller compressor displacement required. It is about 60% more than that of Refrigerant -12 for a given compressor displacement. The cylinder code color is green.