The Armstrong Furnace H4TXV03 Thermal Expansion Valve (TXV) is an HVAC component designed to regulate the flow of R-410A refrigerant in air conditioning and heat pump systems. It works by automatically adjusting refrigerant delivery to the evaporator coil based on cooling demand, ensuring efficient heat absorption and optimal system performance. Commonly used with compatible evaporato... https://www.partshnc.com/h4txv03-armstrong-furnace-r410a-txv-valve-1851365