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Air Purging method in Refer system.


  1. High condensor pressure.
  2. Small bubble in sight glass of condensor\reciever.
  3. Compressor discharge pressure and temp high.
  4. More super heat.
  5. Pressure fluctuations,
  6. Insufficient working(Temp of room is not coming in time)
  7. Pressure temp relations at compressor discharge and reciever would not match with P-T chart of the refrigerant.

Procedure for Purging

  • During normal running , measure liquid refrigerant pressure , temp at outlet of condenser\receiver.
  • Check corresponding saturation temp for the recorded pressure from P-T chart of the refrigerant
  • Compared the measured temp with the determined saturation temp for any sub cooling \under cooling.Adjust the flow of cooling water through condenser to achieve the saturation condition.

Purging of Air.

  • Close condenser outlet valve, 
  • Circulate cooling water .
  • Pump refrigerant to the condenser/receiver till the compressor trips on LP cutout.(Reduce the LP cut out setting above the atmosphere pressure)
  • Circulate cooling water till inlet and outlet temp becomes equal .Ensure complete refrigerant has pump down.
  • Check condensor sea water outlet temp. Check the refrigerant pressure corresponding to this temp from P-T chart of refrigerant has pump down.
  • Due to the  pressure of air they don't agree .
  • Release air from the condensor through the vent and collect it on to a recollecting bottle until the pressure of the refrigerant in the condenser corresponds to the saturation pressure at the cooling water outlet temperature


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