Question 180Motor Plants - QMED

The correct answer is A. In a diesel engine jacket water cooler with sea water cooling the engine jacket cooling water, the jacket water pressure is always kept higher than the sea water pressure. This is to ensure that in case of a jacket water cooler leak, the jacket water expansion tank level will increase, indicating the leak. This prevents sea water from entering the jacket water system, which could lead to contamination and engine damage. The other options are incorrect because B and D state that the sea water pressure is kept higher, which is the opposite of the correct configuration. Option C is incorrect because it states that the jacket water expansion tank level will decrease in case of a leak, when in fact it should increase to indicate the leak.