What is FRV on Airbus A320? (Fuel Return Valve)

The Fuel Return Valve (FRV) is an essential component of the Airbus A320 aircraft’s fuel system. As the name suggests, the FRV is responsible for returning excess fuel back to the fuel tank. It plays a crucial role in maintaining the correct fuel level and pressure within the aircraft’s fuel system, ensuring optimal performance and safety during flight.

The FRV is located in the fuel return line, which connects the engine fuel manifold to the fuel tank. It is typically an electrically controlled valve that opens and closes based on the feedback received from various sensors and control systems. When the fuel pressure or temperature exceeds the specified limits, the FRV opens to allow excess fuel to flow back to the tank. This keeps the fuel system balanced and prevents any potential issues caused by excessive pressure or temperature.

During normal operation, the FRV remains in a closed position, allowing fuel to flow from the tanks to the engine. However, in certain situations, such as during a high-pressure surge or when the fuel system needs to reach a specific pressure for engine start, the FRV may open momentarily to regulate the fuel flow. Once the desired pressure is achieved, the FRV closes again to maintain the optimal fuel system conditions.

The Importance of the Fuel Return Valve

The Fuel Return Valve plays a critical role in ensuring the safe and efficient operation of the Airbus A320 aircraft. Here are a few key reasons why the FRV is important:

1. Fuel System Balancing: By returning excess fuel to the tank, the FRV helps maintain a balanced and stable fuel system. This is crucial for the aircraft’s overall performance, as an imbalanced fuel system can lead to issues such as uneven fuel distribution and potential fuel starvation.

2. Pressure Regulation: The FRV helps regulate the fuel pressure within the system. This is essential to ensure that the fuel is delivered to the engine at the correct pressure, which directly affects engine performance and fuel efficiency. By opening or closing as needed, the FRV helps maintain the optimal fuel pressure for different flight phases.

3. Temperature Control: The FRV also assists in controlling the fuel temperature. Excessive fuel temperature can lead to vapor lock or fuel degradation, both of which can affect the engine’s performance and reliability. By returning excess fuel to the tank, the FRV helps dissipate heat and maintain the fuel at an appropriate temperature.

Airbus, the manufacturer of the A320 aircraft, incorporates advanced fuel system technologies to optimize fuel efficiency and ensure safety. The FRV is an integral part of this system, working in conjunction with other components to deliver the right amount of fuel to the engines throughout the flight.

FRV Operations and Safety Considerations

The Fuel Return Valve operates based on inputs from various sensors and control systems. These inputs include fuel pressure, temperature, and commands from the flight crew or the aircraft’s flight control computer.

During normal flight operations, the FRV remains closed, allowing fuel to flow from the tanks to the engine. However, in the event of abnormal conditions such as a high-pressure surge, the FRV opens momentarily to regulate the fuel flow and prevent damage to the fuel system. Additionally, during engine start, the FRV may open temporarily to reach the required fuel pressure.

It is important to note that the FRV is designed to handle specific maximum pressure and temperature limits. These limits ensure the safety and reliability of the fuel system. If these limits are exceeded, the FRV may not function properly, which can result in fuel system malfunctions or even potential hazards. Proper maintenance and regular inspections are essential to ensure the FRV is in optimal condition and operating within its specified limits.

When inspecting the FRV, technicians check for any signs of damage or wear that could affect its performance. They also ensure that the electrical control signals, mechanical components, and associated plumbing are functioning correctly. Any abnormalities identified during inspections should be addressed promptly to prevent any potential issues during flight.


The Fuel Return Valve is a critical component in the Airbus A320 aircraft’s fuel system, responsible for maintaining fuel balance, regulating pressure, and controlling temperature. It plays a vital role in ensuring the safe and efficient operation of the aircraft’s engines. Understanding the function and importance of the FRV helps aviation professionals and enthusiasts appreciate the intricate systems that contribute to the reliable and precise performance of the Airbus A320.

For More: What is FMGC on Airbus A320? (Flight Management Guidance Envelope Computer)