volkswagen Workshop Repair Guides

Volkswagen Workshop Service and Repair Manuals

ABOUT US
Checking and measuring work with a pressure gauge > < Refrigerant gas loop with expansion valve

Polo Mk4

Refrigerant gas loop with butterfly (throttle) and collection tank
   
Refrigerant gas loop with butterfly (throttle) and collection tank
A - Low pressure section of the refrigerant gas loop.
B - High pressure section of the refrigerant gas loop.

   
ComponentRefrigerant statePressure (in bar)Temperature (in degrees Celsius)
-1- Compressor, section -B-Gasup to 20 bar up to + 70 °C
-2- CondenserFrom gaseous to liquid state, with a vapor stageup to 20 barup to + 70 °C
-3- Butterfly (throttle)Transition from liquid to vapor stateSection -B- up to 20 bar, Section -A- above 1.5 barSection -B- up to 60 ºC, Section -A- above - 4º C
-4- EvaporatorTransition from vapor to gaseous stateabove 1.5 barabove - 4 °C
-5- Collection tankGas  
-6- Compressor, section -A-Gas  

The compressor “adjustment device” keeps the pressures measured at the low-pressure area at approx. 2 bar, regardless the changes in the engine speed regime level. This standard only applies to compressor power; if compressor power limits are exceeded, the pressure will rise → Chapter.
  Note
In vehicles with Adjustment valve for the air conditioning compressor -N280-, the pressure on the low pressure side is altered by the operation of the valve.
   

Checking and measuring work with a pressure gauge > < Refrigerant gas loop with expansion valve