In fluid conveying equipment, centrifugal pumps and multistage pumps are two common types. They differ in working principles, structural designs, performance parameters, and applicable scenarios. Understanding the differences between them can help us make more accurate choices in practical applications.
The core of a centrifugal pump's operation lies in the high-speed rotation of the impeller. When the impeller rotates, it generates a strong centrifugal force, which throws the liquid at the center of the impeller toward the edge of the impeller, completing the liquid conveying in this process. A single-stage centrifugal pump is equipped with only one set of impellers, and the liquid is discharged out of the pump after being pressurized once.
The working principle of a multistage pump is based on that of a centrifugal pump and is developed from it. It has multiple sets of impellers installed on the same pump shaft. After entering the pump, the liquid flows through each stage of the impeller in sequence, and is pressurized once for each stage of the impeller. It is discharged after multiple pressurizations. Through this multi-stage superposition method, a higher output pressure is achieved.
The structure of a single-stage centrifugal pump is relatively simple, mainly consisting of a pump body, a set of impellers, a suction chamber, and a discharge chamber. Its overall volume is small, and due to its uncomplicated structure, daily maintenance is relatively convenient.
The structure of a multistage pump is relatively complex. In addition to having multiple impellers, it also needs to be equipped with guide vanes or partitions to guide the liquid from one stage of the impeller to the next smoothly. At the same time, in order to withstand greater axial force, the multistage pump is equipped with a longer pump shaft and a stronger bearing assembly. In addition, because the pressure of the conveyed liquid is relatively high, the multistage pump has higher sealing requirements to prevent leakage of high-pressure liquid.
In terms of performance parameters, the head of a single-stage centrifugal pump is usually low. However, its flow range is relatively wide, and it can adapt to medium and low head, large flow conveying scenarios.
The outstanding advantage of multistage pumps is their high head. With the superposition effect of multi-stage impellers, their head can easily reach hundreds or even thousands of meters. But relatively speaking, the flow rate of multistage pumps is smaller, but the flow rate is more stable. For example, multistage pumps are commonly used in scenarios that require high-pressure liquid conveying such as boiler feed pumps.
Single-stage centrifugal pumps are widely used in many fields due to their simple structure, low cost, and convenient maintenance. For example, they are often used in agricultural irrigation, urban water supply and drainage, industrial circulating water, and other scenarios with low head requirements.
Multistage pumps are mainly used in scenarios that require long-distance and high-pressure liquid conveying. For example, mine drainage requires pumping water from deep mines, which has high pressure requirements; high-rise building water supply needs to transport water to higher floors, which also requires sufficient pressure. In these scenarios, single-stage centrifugal pumps cannot meet the head requirements, so multistage pumps become the inevitable choice.
Multistage pumps are a special form of centrifugal pumps. The core differences between them lie in the number of pressurizations, structural complexity, head capacity, and applicable scenarios. In actual selection, the most suitable type should be selected according to specific head, flow requirements, and working conditions. With years of experience in the pump industry, TEFFIKO can provide suitable pump solutions for different scenarios to help industrial fluid conveying operate efficiently. If you need it, please feel free to contact us, and we will provide you with 24-hour service.
