Engine: Gas Turbines

1. A Opens completely at a specified lift pressure and remains open until the pressure drops to a specified preset pressure.
2. B Opens completely at a specified lift pressure and closes immediately as soon as the pressure begins to drop.
3. C Gradually opens at a specified lift pressure and closes immediately as soon as the pressure begins to drop.
4. D Gradually opens at a specified lift pressure and remains open until the pressure drops to a specified preset pressure.

Tip: press A-D to answer