Which component is often used in low-pressure refrigerant applications instead of a TXV?

In low-pressure refrigerant applications, capillary tubes are frequently used as they serve as a simple and cost-effective method for controlling refrigerant flow. Unlike a thermal expansion valve (TXV), which modulates the flow based on changes in temperature and pressure, a capillary tube provides a constant restriction to the flow of refrigerant. This design is particularly suitable for small systems where precise control of superheat is less critical.

The capillary tube functions effectively in applications where steady conditions are expected, allowing for adequate refrigerant flow under those conditions. Additionally, there are no moving parts in a capillary tube, which contributes to its reliability and lower maintenance requirements over time.

Other components mentioned, like the expansion valve in a traditional sense, are designed for different applications requiring variable flow control and are not typically employed in low-pressure systems where capillary tubes excel. Receiver driers and compressors also serve different functions within the refrigeration cycle and do not directly replace the role of a TXV in regulating refrigerant flow.