Final answer:
The piping between the condenser and the metering device, typically an expansion valve, is known as the liquid line, which carries the condensed refrigerant in a liquid state.
Step-by-step explanation:
The piping between the condenser and the metering device in an air conditioning or heat pump system is known as the liquid line. In the cycle, after the refrigerant gas is compressed by the compressor, it is forced into the condenser coils. Here, a heat transfer occurs as the gas condenses into a liquid due to the higher temperature and pressure of the gas compared to the room's temperature. Once the refrigerant has condensed into a liquid, it flows through the liquid line to a pressure-reducing valve, typically known as the expansion valve. During the cooling cycle, the liquid is cooled through expansion and then returns to the outdoor evaporator coils to continue the refrigeration cycle.