Refrigerant relief valves are typically located on which HVAC component?

• A. Compressor
• B. Liquid Receiver
• C. Oil Tank
• D. Condenser

Answer: (B)

Safety against overpressure on the liquid side of a refrigerant system is what this item targets. A refrigerant relief valve is placed on the liquid receiver because this vessel stores high-pressure liquid refrigerant after it has been condensed and before it goes to the metering device. If heat leaks in, or if there’s an overcharge or downstream restriction, pressure on the liquid side can rise quickly. The relief valve on the receiver provides a controlled vent path to prevent the receiver (and downstream components) from exceeding its design pressure, protecting the system from damage.

Placing a relief on the compressor isn’t standard because that would vent high-pressure gas from the discharge side, which isn’t the protected point for the liquid portion. The oil tank isn’t a refrigerant pressure vessel, and the condenser is involved in high-pressure gas cooling rather than storing liquid refrigerant, so it isn’t the typical location for a relief valve.