Question 13

Power & Propulsion — Engine Room Test

It’s a long, metal cylinder usually mounted directly on the engine, roughly vertically and by itself, which on larger engines distinguishes it from the engine-mounted component of clue 14 (below) that’s often seen mounted in pairs. While effective at removing contaminants, this item is not designed to handle the large amounts of water that a fuel-water separator does. 

Answer to Question 12: Fuel cooler