Frequently asked questions about multistage pumps
What is a multistage pump and when is it needed?
This is a centrifugal pump in which several impellers are installed in series on one shaft: each stage adds head to the previous one. Such a pump is taken when high pressure at a moderate flow rate is required — supplying water to a height, feeding steam boilers, pressure boosting systems, reverse osmosis, high-pressure cleaning stations.
How many stages do we specifically need?
The number of stages is determined by the required head: the greater the head at the same flow rate, the more stages. For the calculation, the flow rate (m³/h), the geodetic lift height, the pressure losses in the pipeline and the required excess pressure at the end point are needed. Using these data we select the size and the point on the duty curve.
Should a vertical or horizontal design be chosen?
Vertical multistage pumps are more compact in terms of footprint and are convenient for pumping stations and booster groups in cramped rooms. Horizontal ones are simpler to maintain and are more often used where there is free length and convenient access to the seal and bearings is required.
What media can be pumped?
Clean and slightly contaminated low-viscosity liquids without abrasive inclusions: water, condensate, water-glycol mixtures, cleaning solutions, some chemical solutions in the appropriate design. Abrasive and fibrous inclusions are contraindicated for multistage pumps — they quickly wear out the stages and the seals.
How can the energy consumption of such a pump be reduced?
The main source of saving is frequency control: the pump maintains the set pressure or flow value instead of running at constant speed with throttling. The second factor is correct selection: a pump operating far from the optimal point of the curve consumes excess energy and wears out faster. We supply pumps together with frequency converters and control cabinets.