The piping between the condenser and the metering device is called?

The piping between the condenser and the metering device is referred to as the liquid line. This is because the liquid refrigerant is transported from the condenser, where it exits in a high-pressure, liquid state, to the metering device, which regulates the flow of refrigerant into the evaporator for the cooling process.

The liquid line is critical for ensuring the correct delivery of refrigerant to the metering device, which then controls the amount of refrigerant entering the evaporator based on the cooling demand. This portion of the system must be insulated to prevent heat gain, as any heat absorbed would reduce the efficiency of the cooling cycle due to potential vaporization of the refrigerant.

In contrast, the suction line transports vapor refrigerant back to the compressor, while the discharge line carries the high-pressure vapor from the compressor to the condenser. The expansion line is not a standard term used in HVAC systems, as it’s more common to refer specifically to the liquid line when discussing the path of refrigerant between these two components.