Question 19General Subjects - 1st Asst/Chief

The correct answer is A) the pump will overheat. When a centrifugal bilge pump is operated with the discharge valve closed, the pump will continue to circulate the water within the pump housing. This causes the water to heat up, leading to the pump overheating. The pump's impeller is unable to discharge the water, and the internal recirculation of the water results in excessive friction and heat buildup within the pump. The other options are incorrect because: B) the relief valve would only open if the system was designed with one, C) the motor overload would not open unless the motor was drawing excessive current due to the pump overheating, and D) the motor would overheat as a result of the pump overheating, not as a direct consequence of the closed discharge valve.