The York S1-02544172000 Thermostatic Expansion Valve is a replacement component designed for compatible York air conditioning and heat pump systems. It regulates refrigerant flow into the evaporator coil by adjusting the opening according to refrigerant temperature and pressure conditions. This process helps maintain proper evaporator performance, optimize heat absorption, and support... https://www.partshnc.com/york-s1-02544172000-thermo-expansion-valve-3-8-x-5-8-odf-90-psi