A centrifugal firewater pump is operating to pressurize a fire main.
The pump takes suction on a water reservoir.
The reservoir water level and the eye of the pump impeller are both at sea level.
Given:
- The pump has a design shutoff head of 100 feet.
- The required net positive suction head (NPSH) for the pump is 15 feet.
- The reservoir water temperature is 60°F.
- A fire hose connected to the fire main is being used to suppress an elevated fire.
At which one of the following fire hose spray nozzle elevations (referenced to sea level) will the pump first be unable to provide flow?
(Disregard head loss in the fire main and fire hose.)
A. 86 feet
B. 101 feet
C. 116 feet
D. 135 feet
Show Answer
Answer: B
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