Refer to the drawing of a centrifugal pump taking suction from the bottom of an open water storage tank (see figure below).
Given:
- The tank contains 60°F water.
- The eye of the pump impeller is located 50 feet above the bottom of the tank.
- The pump requires a minimum net positive suction head of 4 feet.
Which one of the following describes the effect on pump operation if tank water level is allowed to continuously decrease?
A. The pump will operate normally until tank water level decreases below approximately 20 feet, at which time the pump will cavitate.
B. The pump will operate normally until tank water level decreases below approximately 16 feet, at which time the pump will cavitate.
C. The pump will operate normally until the pump suction becomes uncovered, at which time the pump will cavitate.
D. The pump will operate normally until the pump suction becomes uncovered, at which time the pump will become air bound.
Show Answer
Answer: A
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