Project ForgeA storage vessel exposed to atmosphere (absolute pressure=10.3m of water) has a diameter of 3m and is filled with water to a height of 2m. The pump draws water from the vessel and is located at an elevation of 5m above the bottom of the vessel. The frictional head loss in the suction pipe is 2m of water. If the vapour pressure of the liquid at the operating temperature is 3m of water, then the available NPSH is
- 2.3 m
- B5.3 m
- C6.3 m
- D8.3 m
Explanation
The pump (at 5m elevation) is above the liquid surface (at 2m elevation) — a suction lift of 3m. NPSHavail=Patm(as head)−static lift−friction loss−vapour pressure head=10.3−3.0−2.0−3.0=2.3m.
Source: GATE CH 2010 (2010)
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