Refrigerant Circuit with Restrictor and Reservoir

Arrows point in direction of refrigerant flow.

A-Low pressure side of refrigerant circuit.

B-High pressure side of refrigerant circuit.

Component	Aggregate state of refrigerant	Pressure bar (psi) positive pressure	Temperature in degrees Celsius (Fahrenheit)
-1- A/C compressor B-side	Gas	up to 20 (290 psi)	up to 70 (158)
-2- Condenser	From gas to vapor to fluid	up to 20 (290 psi)	up to 70 (158)
-3- Restrictor	From fluid to vapor	B-side to 20 (290 psi), A-side greater than 1.5 (21.8 psi)	B-side up to 60 (140 psi), A-side warmer than -4 (25)
-4- Evaporator	From vapor to gas	Greater than 1.5 (21.8 psi)	Warmer than -4 (25)
-5- Reservoir	Gas
-6- A/C compressor A-side	Gas

Pressures on A-side are maintained at approximately 2 bar (29 psi) by “regulating” A/C compressor also at various engine speeds. However, this applies only within the performance range of the A/C compressor; if the performance limits of the A/C compressor are exceeded. Refer to → Chapter „Pressures, Checking“. Note In vehicles with A/C Compressor Regulator Valve -N280-, the pressure is modified on the low pressure side by the valve.