One vital AC component you should have for your vehicle is the 4 Seasons AC expansion valve. This is the active control element that meters the refrigerant based on the heat load in the evaporator so as to maintain a given high temperature. It is a common refrigerant regulator wherein it operates such that at a given temperature, it either opens or closes depending on the cooling demand. When the pressure drops and the cooling demand rises, the 4 Seasons AC expansion valve opens to allow more refrigerant flow into the evaporator. Conversely, as the temperature drops, the valve closes to restrict refrigerant flow. The relationship between the refrigerant's temperature and vapor pressure is non-linear so the only way to maintain a constant high temperature over the whole temperature range in the 4 Seasons AC expansion valve is to fill the sensing bulb with the necessary amount of refrigerant. This sensing valve is mounted on or near the evaporator and is responsible for monitoring the cooling demand by measuring the evaporator outlet temperature. The 4 Seasons AC expansion valve has the capacity to detect both temperature and pressure. It efficiently regulates refrigerant flow to the evaporator. Although there are different types of A/C system equipped in vehicles, the 4 Seasons expansion valve is generally classified depending on the type of metering device that a particular vehicle uses. So when you are in need of reliable, high performance, and longer lasting AC expansion valve, you can always find here in our site, high quality 4 Seasons expansion valve that will precisely suit your vehicle's specifications.