In mechanical refrigeration system, moving parts should be lubricated with oil for a long life and effective work. There are different refrigerant and oil, including mineral oil, polyol ester-based oils, alky! benzene, and polvalkylene glycol (PAG), the type of oil used should correspond to the type of refrigerant used. New azeotropic mixture of the refrigerant 134a use polyol ester oil based. In traditional refrigerants require mineral oil. Never mix different types of oil in the system.
The use of oils, which have a low pour point (temperature at which the oil begins to flow). This will avoid wax separation of the low temperature in the system. Wax could score refrigerant aperture control. Due to the low temperatures in which they work, food freezer and frozen food units need the oil with very low pour point and very low wax content. Oil can be no hydrocarbon type that can collect compressor, valves and other parts.
Oil viscosity should be precisely defined for the temperature range that the refrigeration system can be exposed.
Cm. Chapter 9 for more information. When possible, follow the manufacturer's recommendations.
Refrigerant oil should be stored in sealed containers. It must be put in chemically cleaned containers and line, and it must not be exposed to air, where it will absorb moisture. When recharging the system with refrigerant, always add the new oil. Special pressure pumps can be used to pump oil in the low parts of the system. The modified system and change oils, see Chapter 10 step-by-step procedures.
Refrigeration oil is available in single - or five-gallon cans and drums. It is advisable to purchase it in small sealed containers, keeping only enough for each individual service operation. Unused oil will be allowed to remain in the container or oil transferred from one container to another may take some moisture, and perhaps even dirt. Pour point of an oil is the temperature at which it starts flowing. The price of refrigerating oil varies depending on the variety. Low pour point oil more expensive.
Domestic machines with the coolant temperature is below 0F 5F (-18C-15CC) need oil with freezing point-20T (29C). Freezers for food with refrigerant temperatures as low as-SOT (-46CC), pour point-60T (-5Р“РЎ) is desirable. Always seal the oil container after the application of oils from him...