Question 187Motor Plants - 1st Asst/Chief

The correct answer is B) feedwater is too hot. A feed pump for an auxiliary boiler can lose suction if the feedwater is too hot. This is because hot feedwater has a lower density and higher vapor pressure, which can cause cavitation and loss of suction in the feed pump. Regulations require that the feedwater temperature be maintained within a specific range to ensure proper operation of the feed pump and prevent this issue. The other options are incorrect because a low boiler water level, low boiler steam demand, or cold feedwater would not directly cause the feed pump to lose suction. These factors may impact the boiler operation, but do not specifically affect the feed pump's ability to draw in and deliver the necessary feedwater.