Final answer:
The spring in a Thermostatic Expansion Valve (TXV) exerts a closing influence, helping to control the flow of refrigerant into the evaporator coil of an air conditioning system.
Step-by-step explanation:
On a Thermostatic Expansion Valve (TXV), the spring exerts a closing influence on the valve. A TXV is designed to regulate the flow of refrigerant into the evaporator coil in an air conditioning system. The spring within the valve pushes against the diaphragm, moving the valve towards a closed position, which counters the pressure exerted by the refrigerant on the other side of the diaphragm. When the refrigerant pressure is high enough to overcome the spring pressure, the valve opens to allow refrigerant through. Therefore, the spring is a critical component in controlling the valve's operation and maintaining the efficiency and performance of the air conditioning system.