A high-side float valve is used to maintain what in the evaporator?

• A. Constant level of refrigerant in the evaporator
• B. Constant high-pressure in condenser
• C. Constant temperature of refrigerant leave evaporator
• D. Prevent liquid slugging

Answer: (A)

The moment this item tests is how liquid level is controlled inside the evaporator. A high-side float valve uses a float that rises and falls with the liquid level; when the level is at the desired height, the valve closes to stop more liquid from entering, and as refrigerant vapor is drawn off and the level drops, the valve opens again to admit more liquid from the receiver. This keeps the evaporator operating with a steady amount of liquid refrigerant, ensuring efficient heat absorption and consistent vapor production. While maintaining proper level also helps reduce the risk of liquid slugging, the primary function is maintaining a constant refrigerant level in the evaporator. The other options don’t describe what the float valve directly controls: condenser pressure, the temperature of refrigerant leaving the evaporator, or a direct purpose to prevent slugging.