For the gas turbine engine lube oil system shown in the illustration, what is the purpose of the lube oil supply check valves? Illustration GT-0024

Correct Answer: Option B — Prevent lube oil contained in the LO storage and conditioning tank from draining into gearboxes and sumps.

Lube oil supply check valves are critical for maintaining system integrity. By preventing oil from the storage and conditioning tank from draining back into the gearboxes and sumps when the pumps are secured, they ensure the system remains primed for immediate restart and prevent potential flooding of the engine sumps.