Question 103Gas Turbine - Assistant Engineer

The correct answer is B) To prevent reverse flow of oil through a secured pump. The main lube oil system pump check valve in a gas turbine engine serves to maintain system prime and prevent reverse flow of oil through the pump when it is not running. This ensures that the pump is ready to provide lubrication immediately when the engine is started, and prevents oil from draining back out of the system when the pump is shut off. The check valve does not increase system pressure or return oil to the reduction gear sump - those are separate functions handled by other components in the lubrication system. Therefore, option B is the correct answer that describes the primary purpose of the pump check valve.