Multistage pumps are widely used in different industries for two main reasons. They have a high energy efficiency which makes them cost-effective pumping solutions and they provide a flexible range of flow and head which makes them a great choice for many applications.
MULTISTAGE PUMP DESIGN
Design-wise, multistage pumps are centrifugal pumps with multiple stages or chambers, each housing an impeller and guide vanes or volute. These impellers are connected in series by a single shaft. The simplest design of multistage pumps allows the fluid to flow through the chambers linearly.
In principle, fluid pressure goes higher and higher with the addition of every stage. In simpler words, the fluid gains higher pressure as it passes from one impeller to another. Consequently, multistage pumps are able to create higher heads compared with single-stage centrifugal pumps.
MULTISTAGE PUMP OPERATION
Similar to the single-stage centrifugal pump, the impellers are rotated on a single shaft that is driven by a power source (usually a motor). After the pump is primed, the fluid enters the suction port in a continuous manner and passes through the impeller eye. Here, the fluid receives velocity from the rotating impeller and is pushed by centrifugal force to the tips of the impeller vanes. The working fluid then hits the volute and gradually decelerates but gains pressure. But unlike a single-stage pump where the fluid is forced out of the discharge, in a multistage pump, the fluid is processed on the next stage until it reaches the end of the line.
MULTISTAGE PUMP CLASSIFICATION BY ORIENTATION
Multistage pumps come in several configurations. They may be classified according to the number of stages/impellers they use, but they are more commonly subdivided according to the orientation of their impellers.
Horizontal Multistage Centrifugal Pumps
Horizontal multistage pumps have their impellers arranged horizontally with each other. They use a segmented casing with modular interstage parts. The assembly is held between bearing housings, hence making the multistage pump more balanced on high-pressure applications.
Their main difference from the vertical multistage type is their ability to handle higher flow rates.
Multistage pumps are best for high-pressure cleaning, pressure boosting, mine dewatering, snowmaking, cogeneration, reverse osmosis, boiler feed, and condensate applications.
Vertical Multistage Centrifugal Pumps
Vertical multistage pumps feature a vertical shaft where the impellers are stacked on top of each other. The clearances between the impellers are limited, hence this type of pump is ideal for pumping clean water. They cannot tolerate large solids and debris and are vulnerable to deadheading.
The vertical multistage type is also the pump of choice ion sites that don’t have much footprint to spare. They are commonly used in applications like desuperheater feed, high-pressure shower systems, and boiler feedwater.
Sounds like a multistage pump is what your system needs? At ALL PUMPS, we have the most extensive range of multistage pumps from the world’s most trusted manufacturers and brands. Get in touch with us by filling up our contact form and one of our pump experts will get back to you with recommendations on the best solution for your application.