During the compressor operating, the outlet of compressor always
has lots of refrigerant oil. In order to prevent compressor not
loss too much refrigerants and prevent the oil flow to system with
refrigerants to interfere condenser's heat function and
evaporator's cooling function, we need to install an oil separator
between compressor and condenser to separate refrigerant oil and
refrigerants. Then the oil will flow back to the compressor
crankcase, the oil return device operated by the ball valve on the
bottom of separator and uses high-low pressure theory. The oil
separator can ensure the sufficiency of oil in compressor and let
it reach best cooling performance.