What is the main function of the purge valve in a gas turbine system?

The main function of the purge valve in a gas turbine system is to drain low-temperature fuel from the system prior to the gas turbine system start-up. This step is crucial for ensuring that the fuel system is free of any residual fuel that might have cooled and could cause operational issues during ignition.

When starting a gas turbine, especially in cold conditions, it is vital to clear the system of low-temperature or stale fuel. This ensures that only the proper fuel at the correct temperature enters the combustion chamber, facilitating easier ignition and reliable engine performance. By venting the low-temperature fuel and preventing it from entering the combustion system, the purge valve plays a pivotal role in preparing the engine for a smooth and effective start.

Understanding the importance of this function helps highlight the operational reliability of the turbine once it reaches full operational temperature. This makes the correct answer particularly relevant for gas turbine operation excellence.