What is a refrigerant metering device?

A metering device controls the refrigerant flow to the evaporator and separates the system’s high-pressure and low-pressure parts. As the liquid refrigerant passes through the metering device, it is passing from a high pressure to a low pressure region, which lowers the temerature of the refrigerant. Thermostatic expansions valves (TXV) and electronic expansion valves (EEV) are both examples of metering devices.