Patent ID: 6892544

Claim:
A process of operating a gas turbine engine having a plurality of fuel manifolds each having multiple fuel nozzles for supplying fuel to an engine combustion region, comprising the steps of: commencing fuel flow to a pilot manifold and to a primary manifold; starting the engine; stopping fuel flow to the pilot manifold and purging remaining fuel from the pilot manifold; selectively charging a secondary manifold with fuel and subsequently enabling fuel flow from the secondary manifold to the engine combustion region; stopping fuel flow to the secondary manifold and subsequently purging fuel from the secondary manifold; ceasing engine operation by stopping fuel flow to the primary manifold and thereafter purging fuel therefrom, wherein each step of purging comprises supplying air from a pressurized source to the corresponding manifold to displace fuel therefrom into the engine combustion region, and the step of purging fuel from the primary manifold includes opening a purge air control valve to direct high pressure air from an intake compressor region of the engine through a purge air control valve, through a secondary manifold fuel supply valve and to the primary manifold.