🔍 Key Concepts

• Centrifugal pump discharge vs. suction pressure in a closed cooling system • How static head and friction losses affect pressure at different points in the piping • Typical freshwater cooling system flow path: expansion tank → pump → engine jackets → heat exchanger → back to tank

💭 Think About

• Trace the water flow through a standard closed diesel cooling system and mark where the pump is adding energy (pressure) to the water. • Ask yourself: in a running system, is the pressure generally higher just before or just after the pump? Why? • Consider what the expansion tank is there to do in terms of pressure control and air removal—would that usually be a high‑pressure or relatively low‑pressure location?

✅ Before You Answer

• Identify which component is the pump discharge point in the listed choices. • Decide whether an expansion tank is normally operated near system pressure or closer to atmospheric pressure in a closed system. • Consider whether the heat exchanger inlet normally sees higher or lower pressure than the pump outlet, given piping losses and flow direction.