A rise in evaporator pressure causes the automatic expansion valve to?

When there is a rise in evaporator pressure, the automatic expansion valve reacts by closing. This mechanism is designed to maintain the proper pressure and flow of refrigerant in the system. The automatic expansion valve is equipped with a pressure-sensing element that monitors the pressure in the evaporator. If the pressure exceeds a certain threshold, it indicates that the evaporator is receiving too much refrigerant, risking flooding or poor heat exchange.

By closing in response to the increased pressure, the valve effectively reduces the flow of refrigerant into the evaporator, allowing it to stabilize and operate efficiently. This regulation is crucial for maintaining optimal performance and preventing potential damage to the system components. Hence, the action of closing helps to ensure that the evaporator can continue to absorb heat effectively without being overwhelmed by excess refrigerant.