Question 370Motor Plants - Assistant Engineer

The correct answer is C) 15 psig. The cooling water pump must produce a discharge head that is equal to the sum of the pressure drops through the engine (10 psig) and the heat exchanger (4 psig), which is 10 psig + 4 psig = 14 psig. Rounding this up to the nearest whole number gives 15 psig as the minimum discharge head required for the cooling water pump. The other options are incorrect because: A) 4 psig is not sufficient to overcome the total pressure drop in the system. B) 6 psig is also not enough to overcome the total pressure drop. D) 28.7 psig is more than the required discharge head.