🔍 Key Concepts

• Heat exchanger (cooler) pressure relationships between two fluids • Risk and consequences of seawater leaking into lube oil or jacket water systems • Which fluid is more critical to keep clean: seawater, jacket water, or lube oil

💭 Think About

• If a tube in the cooler fails, in which direction do you want any leakage to flow to protect the engine? From seawater to the other fluid, or from the other fluid to seawater? • For the jacket water cooler, which side (seawater or jacket water) should have the higher pressure to best protect the engine’s cooling system? • For the lube oil cooler, which side (seawater or lube oil) should have the higher pressure to avoid serious engine damage and expensive clean-up?

✅ Before You Answer

• For each cooler, decide which fluid must NOT be contaminated and which fluid is easier to lose or discharge. • Remember that fluid will leak from the higher-pressure side to the lower-pressure side if there is a leak. • Check that your chosen option has the pressure relationships arranged so that any leak will send flow away from the critical internal engine fluid and toward the less critical fluid.