【Daily Question: Pump Equipment】Multiple-choice Question 2018.11.17
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This post was last edited by 3983596_FPPZ on 2018-11-21 at 20:39; the file bg14.jpg was edited as well. To prevent pump damage or motor overload, the following pumps should be started with their valves open: A Vortex pump, B Axial flow pump, C Plunger pump, D ZA50-250 chemical centrifugal pump. Answer: ABC. For centrifugal vane pumps, those whose shaft power decreases as the flow rate increases according to their performance curves should be started with their valves open, in order to avoid the impact caused by high shaft power at zero flow rate on the pump and motor, which could lead to damage to them; hence, AB is the correct choice. All positive displacement pumps should be started with the valves open, as closing the valves will cause pressure buildup in the pump, which can lead to damage to it. Plunger pumps are a type of positive displacement pump; therefore, C is also the correct answer.
A vortex pump (also known as an eddy current pump) is a type of vane pump
The N-Q curve of a centrifugal pump is an upward-sloping curve; the power is at its lowest when the flow rate is zero. The N-Q curve of a vortex pump is a descending curve, with maximum power at zero flow rate.