Service Port HVAC: Description and Operation

The refrigerant system service ports are used to charge,recover/recycle, evacuate, and test the air conditioning refrigerant system. Unique service port fitting sizes are used on the R-134a system, to ensure that the refrigerant system is not accidentally contaminated by the use of the wrong refrigerant (R-12), or refrigerant system service equipment.

The high pressure gauge port is located on the compressor discharge line. The low pressure gauge port is located on the suction line.

After servicing the refrigerant system, always reinstall the service port caps.