Problems caused by a decrease in the inlet pressure of a centrifugal pump
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This post was last edited by sdhklh on 2020-2-26 at 10:36. Since the inlet pressure of the single-stage centrifugal pump decreased by 0.05 MPa, the outlet pressure dropped by 0.3 MPa as well (due to backflow at the inlet; the density of the fluid is 1.4). The flow rate is only 20 m3/h (the rated flow rate is 30 m3/h, with a rated head of 40 m), and cavitation has not yet occurred. Please help analyze the reasons for the low traffic!
What did you use to determine that cavitation did not occur? A 3% decrease in head indicates cavitation
It is suspected that the phenomenon is caused by a blockage in the inlet pipeline, which reduces the flow area, but there has not been yet an opportunity to inspect the inlet pipeline. Please help analyze and determine the cause
Could you please specify whether it is a new pump or an old one? Do you have the performance curve from the manufacturer?
The design institute tells you that, according to the API definition, a 3% decrease in head is considered cavitation. A decrease of 0.3 MPa like this definitely exceeds 3% of the head loss, and can be defined as cavitation. When cavitation occurs, the flow rate decreases. Please check whether the inlet filter is clogged and whether the temperature of the inlet medium is too high.