Question 375General Subjects - Assistant Engineer

The correct answer is C) Replace the wearing rings. Wearing rings are an essential component of a centrifugal pump, and if they become worn, it can lead to a gradual decrease in the pump's discharge pressure. As the wearing rings wear down, the clearance between the impeller and the pump casing increases, allowing more fluid to leak back from the discharge side to the suction side, reducing the overall pump efficiency and discharge pressure. The other options are incorrect because: A) Throttling the suction valve would further reduce the pump's suction, exacerbating the issue; B) Replacing the lantern rings would not address the problem of worn wearing rings; and D) Throttling the discharge valve would not fix the underlying issue of the worn wearing rings.