Thermostatic Expansion Valve
A control mechanism for cooling in air conditioning systems.
- A bulb of gas senses temperature. If temperature gets too hot, pressure inside bulb increases, and a diaphragm pushes the refrigerant orifice more open. This allows more refrigerant to pass through, cooling the system. This happens automatically. See video at this time, going from normal to a hot spike that is stabilized: [1]