Question 371Motor Plants - Assistant Engineer

The correct answer is A) the jacket water pressure should always be greater than the sea water pressure. In a diesel engine jacket water cooler, the jacket water (fresh water) is used to cool the engine. The sea water is used to cool the jacket water. For proper cooling, the jacket water pressure needs to be greater than the sea water pressure. This ensures that any leaks will result in the jacket water leaking into the sea water, rather than the potentially dirtier sea water leaking into the jacket water system. This helps maintain the integrity of the fresh water cooling system. The other options are incorrect because: B) the jacket water pressure does not need to be less than the sea water pressure, C) the jacket water temperature is not required to be less than 60°F, and D) the sea water temperature is not required to be less than 40°F. The key requirement is that the jacket water pressure is maintained at a higher level than the sea water pressure.