Service Valves

Fig 1: Identifying Service Valves

Courtesy of VOLVO CARS CORPORATION

1. Service valve for emptying and vacuum pumping.
2. Service valve for emptying, vacuum pumping and filling of refrigerant.

There are two service valves, one on the low pressure side and one on the high pressure side. To avoid incorrect connection the valves have different dimensions.

Filling of refrigerant normally takes place on the low pressure side. The liquid refrigerant then stays in the accumulator and there is no risk that liquid refrigerant will flow to the compressor.

In an orifice system such as this, filling can also take place on the high pressure side.