Question 377Steam Plants - 1st Asst/Chief

The correct answer is C) loss of oil flow across one of the bearings. When there is a sudden increase in pressure in a forced lubrication system, it typically indicates a blockage or restriction in the oil flow path, often caused by a loss of oil flow across a bearing. This increased pressure is the system's response to maintain the necessary oil flow to critical components, such as bearings, despite the restriction. The other options are incorrect because: A) a high lube oil sump level would not cause a sudden pressure increase, B) a clogged pump suction would prevent the system from building pressure, and D) a ruptured tube in the lube oil cooler would more likely result in a pressure drop rather than an increase.