FAA Powerplant Written Practice Test

What is the purpose of the relief valve installed in the venting system of a turbine engine oil tank?

1. Prevent oil pump cavitation by maintaining positive pressure on its inlet

2. Regulate the temperature of the oil

3. Control the flow rate of fuel to the engine

4. Ensure proper lubrication of all engine components

The correct answer is: Prevent oil pump cavitation by maintaining positive pressure on its inlet

The purpose of the relief valve installed in the venting system of a turbine engine oil tank is to prevent oil pump cavitation by maintaining positive pressure on its inlet. Cavitation occurs when the pressure at the pump inlet drops below the vapor pressure of the oil, leading to the formation of vapor bubbles that can disrupt the flow of oil and potentially cause damage to the pump. By maintaining a slight positive pressure in the oil tank, the relief valve helps ensure that the oil pump receives a consistent flow of oil without encountering cavitation, thereby improving reliability and performance. This function is crucial for the effective operation of the oil system, as a stable oil supply is necessary to maintain lubrication throughout the engine. Proper lubrication is essential for minimizing friction and wear on moving parts, thus ensuring the longevity and efficiency of the turbine engine.