Oil separators are designed to separate the oil that is carried out by the refrigerant vapors from the compressor crankcase. They are installed on the pressure pipeline between the compressor and the condenser. The oil is separated by virtue of an abrupt change in the vapor direction and deceleration thereof.
What oil separators are mainly intended for is efficient purification of oil from the pressurized refrigerant’s vapor, and return thereof to the compressor crankcase. This dramatically increases the system’s general performance by preventing excessive oil circulation through the system.
Basically, an oil separator guarantees that oil is returned to the compressor crankcase is the oil level is preserved.