🔍 Key Concepts
• Centrifugal and positive displacement pump operation and what creates discharge pressure
• How internal wear or damage (impeller, casing, clearances, seals, valves) affects pump output
• Function of a pump relief valve and its spring in controlling pressure and protecting the system
💭 Think About
• If the pump is running but the discharge pressure is low, what specific mechanical problems inside the pump body itself could reduce pressure or flow?
• What does the relief valve do with the liquid when its spring does not hold proper tension (too weak or stuck open)? How would that show on a pressure gauge?
• Could either of these failures realistically prevent the pump from building and holding the required discharge pressure, or would one of them affect only over‑pressure protection?
✅ Before You Answer
• For each statement (I and II), decide whether that specific failure would cause low or unstable discharge pressure, not just any pump problem
• Consider whether a failed relief valve spring would tend to cause low pressure, excessive pressure, or intermittent pressure, based on whether it stays open or shut
• Ask: if this part failed completely, could the pump still build and maintain the necessary discharge pressure, or would the fluid simply recirculate or leak internally instead of going to the system?