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A brief analysis of R134A refrigerant - the main differences between R134a and R12 refrigeration systems 1. The container that stores R134a is light blue, while the container that stores R12 is white. 2. The R134a refrigeration system connecting hose is specially made of rubber and nylon, and has the stamp of the Society of Automotive Engineers (SAE#J2196) on it. ； The connecting hoses of R12 refrigeration systems are commonly used ordinary rubber pipes. 3. The R134a refrigeration system connecting pipes are color-coded (low-pressure pipes are blue with black stripes, high-pressure pipes are red with black stripes, ordinary pipes are yellow with black stripes), while R12 refrigeration system connecting pipes are unmarked. 4. The R134a refrigerant inlet uses a quick connector, while the R12 refrigeration system uses a threaded interface. 5. The connector connecting the hose and instrument of the R134a refrigeration system has a 1/2-inch thread, and the connector of the high-pressure port is larger than that of the low-pressure port. ； The connector connecting the hose and instrument of the R12 refrigeration system has a 7/16in thread. 6. Compared with the R12 refrigeration system, the R134a refrigeration system has higher pressure and temperature and requires a larger cooling fan. Second, the main features of refrigerant R134a are 1. R134a does not contain chlorine atoms and has no destructive effect on the atmospheric ozone layer. ； 2.R134a has good safety performance (non-flammable, non-explosive, non-toxic, non-irritating and non-corrosive) ； 3. The heat transfer performance of R134a is relatively close, so it is easier to modify the refrigeration system. 4.R134a has better heat transfer performance than R12, so the amount of refrigerant can be * * reduce. 3. Precautions for use and maintenance of R134a. 1. Instruments, equipment and measuring tools used for R134a cannot be interchanged with those used for R12, because if R12 is mixed with R134a, the compression surface will be damaged, and the instrument and preparation may also be damaged. 2. Refrigeration oil of R134a and R12 refrigerants cannot be mixed because R134a is incompatible with the refrigeration oil of R12 refrigeration system. R12 refrigeration systems generally use domestic No. 18 and No. 25 refrigeration oils or Japanese SUNISO3GS, SUNISO4GS, and SUNISO5GS refrigeration oils, while R134a systems generally use synthetic polyalkylene glycol, that is, PAG (Polyalokylene Glycol) oil or polyester (Poly Ester) oil. 3. Wear safety glasses and gloves when overhauling the refrigeration system. Do not let liquid refrigerant come into contact with your skin, especially your hands and eyes, to avoid frostbite. 4. Same as PAG oil and R134a, there will be two layers of separation (separation of the two) in the high temperature area and low temperature area. Therefore, when filling R 134, it needs to be placed in a container of hot water for heating, but the temperature should not exceed 40°C. It is absolutely forbidden to use a heating device such as a blowtorch for heating. Try to prevent the two layers from separating to avoid adverse effects on the exhaust pressure and refrigeration of the compressor. 5. The R134a system must use special sealing rings and gaskets. The cooling oil used will cause the sealing rings and gaskets used in the R12 system to bubble and fail, resulting in refrigerant leakage. 6. When filling R134a, the container containing R134a should be kept upright to ensure that R134a enters the system in a gaseous state. Otherwise, R134a may enter the compression surface in a liquid state, causing damage to the compressor. In addition, the filling operation must be carried out in a place with air circulation to prevent the operator from suffocating due to cylinder oxygen. 7. The liquid storage dryer (or gas-liquid separator) must be sealed and stored, and its installation must be rapid. ； Otherwise, air entering the liquid storage dryer (or gas-liquid separator) will weaken the temperature absorption capacity of the desiccant and even render it ineffective.