🔍 Key Concepts

• Closed fresh water cooling system layout on a diesel engine • Purpose and function of an expansion tank (accommodating thermal expansion and removing air/steam • Behavior of air bubbles and hot coolant in a circulating system

💭 Think About

• Think about where air and steam naturally travel within a circulating liquid system—do they collect at the top or at the bottom? • If the expansion tank must allow coolant to expand and vent air, would it work better at a high point or at a low point in the system? • Consider where you would place a tank so that the system stays completely flooded with coolant and avoids air pockets in the engine and cooler.

✅ Before You Answer

• Verify where air pockets tend to form in piping systems and how expansion tanks help remove them • Consider that the expansion tank should be at a point that remains uncovered by air and can maintain a positive static head on the circulation pump suction • Check basic diagrams of diesel engine closed cooling systems to see the relative vertical position of the expansion tank compared to the engine and coolers