What Is A Single-stage Pump Or A Multi-stage Pump

Aug 21, 2024

Some multi-stage pumps and single-stage pumps can achieve the same pressure, but when choosing, multi-stage pumps are still used. What is the basis for choosing multi-stage or single-stage pumps? Or for other reasons? What is the difference between single level and multi-level? Is it just a difference in the number of impellers?
1. A single-stage pump refers to a pump with only one impeller and a maximum head of only 125 meters;
2. A multi-stage pump refers to a pump with two or more impellers that can suction and pressurize water in stages and multiple stages, thereby lifting the water to a high position. The head can be increased or decreased according to the needs of the pump impeller stages; When multi-stage pumps require two-stage motors for single stage pump head, four stage motors can be used by increasing the number of impellers to improve pump service life and reduce unit noise;
3. When the actual required head of the pump is less than 125 meters, the choice of single-stage pump or multi-stage pump can be comprehensively considered based on factors such as the pump room area, pump price (multi-stage pumps are generally more expensive than single-stage pumps), etc.
The use of multi-stage pumps is mainly due to considerations of economic applicability, which are introduced in fluid machinery books. The difference between single-stage and multi-stage is the compression stage. A compression stage not only refers to the impeller, but also includes static blade retaining rings, inter stage seals, and so on.
According to the head, whether it is a single-stage pump or a multi-stage pump, multi-stage pumps have lower efficiency than single-stage pumps. If both single-stage and multi-stage pumps can be used, single-stage pumps are the first choice. If a single-stage pump can meet the needs, try to use a single-stage pump. Multi stage pumps have complex structures, many spare parts, high installation requirements, and are very difficult to maintain.
A multi-stage pump is the sum of single-stage pumps, and can achieve high head and outlet pressure.