 Thermal expansion valve

A thermal expansion valve or thermostatic expansion valve (often abbreviated as TEV, TXV, or TX valve) is a component in refrigeration and air conditioning systems that controls the amount of refrigerant released into the evaporator thereby keeping superheat, that is, the difference between the current refrigerant temperature at the evaporator outlet and its saturation temperature at the current evaporating pressure, at a stable value, ensuring that the only phase in which the refrigerant leaves the evaporator is vapor, and, at the same time, supplying the evaporator coils with the optimal amount of liquid refrigerant to achieve the optimal heat exchange rate allowed by that evaporator.In addition, some thermal expansion valves are also specifically designed to ensure that a certain minimum flow of refrigerant can always flow through the system.