Question 279General Subjects - QMED

The correct answer is A) the pump to operate sluggishly. Excessive lost motion in the valve mechanism of a duplex reciprocating pump will cause the pump to operate sluggishly. This is because the lost motion reduces the efficiency of the valve actuation, leading to decreased pump performance and reduced flow rate. The other answer choices are incorrect: B) is incorrect because excessive lost motion would not cause the pump to short stroke continuously. C) is incorrect because cushioning valves are not directly affected by lost motion in the main pump valves. D) is incorrect because excessive lost motion would not cause the pistons to stop in mid-stroke.