🔍 Key Concepts

• Trace the piping to and from the scavenge/charge air cooler(s) in the diagram, and note which cooling loop it connects into. • Compare the line style and color for that piping with the legend for central cooling water, jacket cooling water, and sea water. • Notice which loop is connected to the expansion tank for fresh water and which loop passes through the central cooler that is itself cooled by sea water.

💭 Think About

• From the scavenge air cooler symbol on the main engine, follow the cooling water lines backward: do they join the same circuit as the cylinder jackets, or a separate circuit that also serves lube oil coolers? • Ask yourself: is the charge air cooler on the ‘hot’ engine jacket loop, or on a ‘cooler’ secondary fresh‑water loop that is itself cooled by sea water? • Look for where the cooling water from the charge air cooler returns: does it go back to the jacket water pumps, or to the pumps labeled as central cooling water pumps?

✅ Before You Answer

• Match the line type at the charge air cooler to the legend (central cooling, jacket cooling, or sea water). • Confirm that the same line type from the charge air cooler also connects to the central cooler and camshaft/main lube oil coolers, not to the jacket water pumps. • Verify that the cooling medium you choose is a fresh water loop, not raw sea water, based on its connection to the expansion tank for fresh water.