Centrifugal pump install in series refers to a pump that is installed in series by two or more units instead of a single unit.
When multiple centrifugal pumps are operated in series, it must be noted that the rear pump casing and shaft can be used to withstand sufficient pressure. The pump with the best pumping performance should be placed in the first series position.
The pump in front of the series at start-up must be able to provide sufficient pressure before starting the pump in series to avoid cavitation as much as possible. When shutting down, the pump with a lower pressure level cannot be shut down as long as the pump behind the series is still running. Otherwise, a pump that has been turned off but is still rotating slowly draws flow through the throttling position, resulting in an insufficient effective cavitation margin (NPSHA) for the adjacent pump. If necessary, configure the motor with a two-way locking device.
After a single pump has been modified into a pump that operates in series, both the lift and the flow are increased. Therefore, care must be taken to ensure that sufficient necessary cavitation margin (NPSHR) is maintained.
If the conditions required above are met, it is also guaranteed that the pump that is not driven will not be involved in the operation due to the flow, or that the pump bypasses the bypass when it is stopped, then this series operation The pump unit is suitable for multi-stage adjustment.
If you don't use multi-stage on/off adjustment, it's much simpler and cheaper, because you don't need to connect the centrifugal pumps in parallel mode, but only need to connect the impeller and the guide impeller in a common pump casing. For example, a multi-stage centrifugal pump product.
