The two pumps cannot be turned on at the same time
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I have a few questions: 1. Two pumps share the same inlet and outlet pipelines; when both shielded pumps are turned on, one pump has pressure at its outlet while the other has no pressure at all at its outlet. 2. I’m wondering if the flow rate in the inlet pipeline is not sufficient to meet the pumping requirements of both pumps 3. Each one can be turned on individually and still function. Please, expert, help me answer it. Thank you
It’s not clear what type of pump it is or what the properties of the medium are; it would be best to clarify this for reference. If it is a centrifugal pump, it could be a problem with the check valve or issues related to operation after startup. It’s best to explain the process of operation.
The inlet flow is insufficient; the same shielded pumps have experienced issues with flow competition. Increasing the inlet flow or pressure will yield better results.
It’s probably about maximizing flow rate. Although the head of the two pumps is the same, there is still a slight difference; the pump with a higher outlet pressure can allow the medium to flow out properly, while the pump with a lower outlet pressure doesn’t have enough pressure to overcome the check valve at the pump outlet, resulting in no flow.
There is a problem with the layout of the inlet pipelines; the main pipeline should be located midway between the inlets of the two pumps
The upstream flow rate is low; the diameter of the inlet pipe section is DN150. With a flow velocity of 2 meters per second, the flow rate is above 100 m3/h. If the inlet flow rate is 100, both pumps will have flow. Reduce the outlet valve of the pump with flow to see if the other pump starts to deliver flow. At the same time, increase the valve setting of the minimum flow circuit for pumps with excessive flow, to ensure that too much flow is not drawn.
The cross-sectional area of the pump inlet manifold is smaller than the sum of the cross-sectional areas of the inlet pipes of the two pumps. When both pumps are turned on, will there be flow at the outlet of pump A and no flow at the outlet of pump B?
It depends on the medium and the length of the pipeline; if the medium tends to vaporize or if the pipeline is long, the combined inlet pipe for the two pumps needs to be smaller.
Both the pipe diameter and the piping layout may have defects; the common pipes for the pumps should be larger to meet the flow requirements. The pipes should not be arranged on only one side – try reducing the outlet size of pump A
It is designed with one active and one standby unit; there is no dual-active design