What is the function of a drain valve in a turbine engine's combustion chamber?

What is the function of a drain valve in a turbine engine's combustion chamber?

• A. To regulate air flow
• B. To vent pressure
• C. To drain fuel that accumulates in the chamber after shutdown or during a false start
• D. To inject fuel

Answer: (C)

Fuel can remain in the combustor after shutdown or during a false start. The drain valve provides a controlled path to purge and remove this residual fuel from the combustion chamber, routing it to the drain system so it doesn’t pool near hot surfaces. This reduces the risk of unintended ignition when restarting. It’s not about adjusting air flow, injecting fuel, or venting chamber pressure—the drain valve’s purpose is specifically to purge and drain leftover fuel.

Fuel can remain in the combustor after shutdown or during a false start. The drain valve provides a controlled path to purge and remove this residual fuel from the combustion chamber, routing it to the drain system so it doesn’t pool near hot surfaces. This reduces the risk of unintended ignition when restarting. It’s not about adjusting air flow, injecting fuel, or venting chamber pressure—the drain valve’s purpose is specifically to purge and drain leftover fuel.