the inlet header 1 the second part which carries the remainder of the mass flux includes the high pressure side 15 a of the superheating heat exchanger 15 and an additional expansion device 24 attached to the inlet header 1 as well if the expansion device 13 is an expansion valve then the sensing bulb 19 of the valve should be located at outlet from the vapor outlet 18 it the expansion device 24 is an expansion valve then a sensing bulb 25 of the valve should be located at outlet from the low pressure refrigerant of the superheating heat exchanger 15 as per fig7 in this case the expansion valve 24 operates on a reversed principle it opens its orifice when the superheat is decreased and it closes its orifice when superheat is increased if the expansion device 24 is a capillary tube the capillary tube may be used as the high pressure side 15 a of the superheating heat exchanger 15 i e within the superheating heat exchanger 15 as shown on fig8 when as a result of maldistribution the amount of liquid in the outlet header 2 is increased then the cooling effect on the capillary tube is increased as well and the capillary tube capacity is increased as well thus the increased refrigerant mass flow rate through the high pressure side handles the increased amount of liquid in the outlet header 2 fig9 adds the liquid separator 21 to.