Exam Question
(a) Describe reasons for vibrations on centrifugal pumps while running (6)
(b) Give reasons for insufficient pressure developed by the centrifugal pumps (6)
(c) How is wear ring clearance of centrifugal pump measured (4)
Class 4 (4th Engineer)
MEP
📅 Mar 2023
Reference Answer
### (a) Reasons for Vibrations on Centrifugal Pumps while Running
Vibration in centrifugal pumps is a symptom of underlying mechanical or hydraulic issues that can lead to premature failure of bearings, seals, and structural components. A systematic approach is required for diagnosis. The primary reasons include:
1. **Misalignment:** This occurs when the rotational centrelines of the pump and its driver (e.g., electric motor) are not collinear.
* **Types:** Can be parallel (offset) or angular. Both types induce cyclic stresses on the coupling, shafts, bearings, and seals, leading to vibration at 1x and 2x the running speed.
Vibration in centrifugal pumps is a symptom of underlying mechanical or hydraulic issues that can lead to premature failure of bearings, seals, and structural components. A systematic approach is required for diagnosis. The primary reasons include:
1. **Misalignment:** This occurs when the rotational centrelines of the pump and its driver (e.g., electric motor) are not collinear.
* **Types:** Can be parallel (offset) or angular. Both types induce cyclic stresses on the coupling, shafts, bearings, and seals, leading to vibration at 1x and 2x the running speed.
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