🔍 Key Concepts

• Piston cooling systems on large, slow-speed, crosshead diesel engines • How reciprocating motion affects the flow of cooling water to a moving piston • The need to keep cooling water and lube oil separated inside the engine

💭 Think About

• Think about what is special about a telescopic pipe compared to a fixed pipe when connected to a moving piston. • Consider where the water-cooled piston is located and how cooling water must reach it as it moves up and down. • Ask yourself which fluids are where: where is the lube oil, where is the piston cooling water, and what problem the telescopic feature is trying to solve.

✅ Before You Answer

• Identify which choice clearly involves both moving connection to the piston and separation of cooling water from lube oil. • Eliminate any choices that talk about problems not directly related to how water gets into a moving piston (e.g., general crankcase issues). • Focus on the option that deals with maintaining a cooling water flow to a moving piston without mixing with lube oil.