Analysis of pressure fluctuations in centrifugal pumps; please provide your analysis
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This post was last edited by Zhongheng Pump Industry on 2020-6-19 09:19. Two centrifugal pumps are connected in parallel, with one in operation and the other as a backup. In through the same main pipe, out through the same main pipe. Turn on one of them, and the pressure remains stable. Turn on another one; there is pressure fluctuation. Note: Performance tests were conducted before leaving the factory, and neither pump showed any fluctuations. Please take the time to analyze what causes these pressure fluctuations. Thank you first! ! !
You may be an expert, but the information you’ve provided is too limited....... Is there a trend of pressure fluctuations?
Is the piping layout the same? Is there any flow competition?
The imported filter can be checked
It is certainly the differences in the lengths of the pipelines connecting the two pumps, as well as the placement of valves and elbows, that lead to uneven operating conditions of the equipment. This results in one pump operating at full flow while the other operates with insufficient flow, causing fluctuations in the outlet pressure. It is recommended to check whether the flow rates or current levels of the two pumps are the cause of this issue
1 Check if there is an issue with the rotation direction; then inspect the pipelines
Although the main inlet and outlet pipes for the two pumps are the same, the filters and inlet valves of each pump should be separate; it is advisable to check the inlet filter of the pump experiencing pressure fluctuations to see if it is clogged
Ask the manufacturer for the head and flow curve of the centrifugal pump. If two pumps are connected in parallel, the curve of the pump’s working point relative to the dead center must rise continuously. It is advisable that the increase in head be greater than 10%. Based on your description, the most likely phenomenon is a hump in your pump curve.
With the motor direction changing, is there something wrong with the check valve?
The problem might lie with the valves, pipes, or filters; check them carefully
Are 2 pumps started simultaneously? Simultaneous startup is likely due to the different head of one of the pumps, or blockage in the flow of one pump caused by the tee connection in the outlet pipeline! If it is being tested on a single unit, it’s possible that there is internal leakage in the check valve! !