Centrifugal pump casing and pressure recovery: Does the casing convert kinetic energy into pressure energy before discharge? Assume a standard volute or diffuser-type casing and steady incompressible flow. Choose the correct option (true/false with reasoning).
Mechanical Engineering
Hydraulic Machines
Difficulty: Easy
Choose an option
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AYes — the volute/diffuser casing recovers velocity head into static pressure before the water leaves the casing.
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BNo — the casing only guides the flow; there is no pressure recovery.
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CTrue only for turbine pumps, not centrifugal pumps.
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DTrue only during priming and not in normal operation.
Answer
Correct Answer: Yes — the volute/diffuser casing recovers velocity head into static pressure before the water leaves the casing.
Explanation
Concept
- The volute/diffuser increases flow area, reducing velocity and converting kinetic energy to static pressure (diffusion effect).
Why this is trueBy Bernoulli's principle and diffuser action, a gradual area increase lowers V and raises p, improving static head before discharge.
Common pitfallsConfusing impeller (adds energy mainly as velocity) with casing (recovers part of that velocity as pressure).
Final AnswerTrue — the casing converts kinetic energy to pressure energy before the water exits.