What Is a Thermostatic Expansion Valve?
The Thermal Expansion Valve (TXV), also known as the thermostatic expansion valve, is a crucial component found in most refrigeration and air conditioning systems. Positioned just before the evaporator, its main role is to precisely regulate the flow of refrigerant entering the evaporator to optimize system efficiency and prevent liquid refrigerant from reaching the compressor. How Does the TXV Work? The TXV manages the refrigerant’s pressure and flow by maintaining a separation between the high-pressure side (liquid refrigerant from the compressor) and the low-pressure side (the evaporator). When the high-pressure liquid refrigerant passes through the TXV orifice, its pressure drops significantly, causing it to partially evaporate and absorb heat inside the evaporator coil. Main Components of a TXV: Valve body Pin Sensing bulb Spring Diaphragm Working Principle The sensing bulb detects temperature changes at the evaporator outlet. As the cooling load changes, the bulb’s refrigerant pressure changes, causing the diaphragm to move the pin. This movement adjusts the orifice opening, increasing or decreasing refrigerant flow to maintain optimal superheat (the vapor temperature above boiling point). The valve balances the forces of the sensing bulb and spring to ensure just the right amount of refrigerant flows to the evaporator, improving system...
View Article Read More