In the classification system of centrifugal pumps, both the Overhung Single - Stage Single - Suction Pump (BB1) and the Overhung Single - Stage Double - Suction Pump (BB2) are commonly used types. However, there are significant differences between them in terms of structural design, performance, and application scenarios. Clarifying these differences is of great significance for practical selection and application.
Its core structural feature lies in the single - suction design, where liquid enters the pump body only from one side of the impeller. The overall structure is relatively compact. One end of the pump shaft is supported by bearings, and the other end extends into the pump cavity and is connected to the impeller, forming an overhung layout. No additional intermediate support structure is required, so it is more flexible in terms of installation space requirements.
It adopts a double - suction design, allowing liquid to enter simultaneously from both sides of the impeller. This design results in a symmetrical distribution of the impeller's water inlet channels. The internal flow channel structure of the pump body is more complex, and the overall volume is usually larger than that of the Overhung Single - Stage Single - Suction Pump (BB1). At the same time, due to the higher requirement for force balance of the double - suction structure, the design of its bearing system is also more precise to cope with the pressure distribution changes caused by symmetrical water intake.
In terms of flow performance, the Overhung Single - Stage Single - Suction Pump (BB1) has a relatively limited liquid delivery volume per unit time due to single - side water intake, making it more suitable for scenarios with low flow requirements. In contrast, the Overhung Single - Stage Double - Suction Pump (BB2), relying on the advantage of double - side water intake, can achieve a larger liquid delivery volume at the same rotation speed, and performs particularly well in working conditions that require large - flow delivery.
In terms of operational stability, the symmetrical water intake structure of the Overhung Single - Stage Double - Suction Pump (BB2) can effectively balance the pressure on both sides of the impeller, reducing vibration and noise caused by uneven pressure, thus achieving stronger stability during operation. In comparison, the single - side water intake of the Overhung Single - Stage Single - Suction Pump (BB1) causes the impeller to bear a certain one - way pressure, which may lead to a larger vibration amplitude during long - term operation and have a certain impact on the long - term service life of the equipment.
In addition, in terms of cavitation performance, the double - suction design of the Overhung Single - Stage Double - Suction Pump (BB2) reduces the flow rate of liquid when it enters the impeller, lowering the probability of cavitation. It has a wider range of applicable medium temperatures and suction conditions. However, due to the limitation of the water intake method, the Overhung Single - Stage Single - Suction Pump (BB1) has a relatively higher net positive suction head (NPSH) and stricter requirements on the suction conditions of the medium.
Based on the above - mentioned structural and performance characteristics, the Overhung Single - Stage Single - Suction Pump (BB1) is more suitable for small and medium - sized conveying systems, such as water supply in civil buildings, liquid circulation in small industrial production lines, and agricultural irrigation. These scenarios usually have low flow requirements and limited installation space, and the compact structure and convenient installation characteristics of the BB1 pump can give full play to their advantages.
The Overhung Single - Stage Double - Suction Pump (BB2), on the other hand, is widely used in large - scale projects that have high requirements for flow and stability, such as urban water supply and drainage systems, circulating water conveying in large power plants, cooling water treatment in the metallurgical industry, and water diversion and drainage in water conservancy projects. In these scenarios, the demand for large - flow delivery and the requirement for long - term stable operation can be perfectly matched with the performance advantages of this pump type.
In terms of maintenance, the Overhung Single - Stage Single - Suction Pump (BB1) has a simple structure and a small number of components. The daily inspection and replacement of vulnerable parts are more convenient, with a shorter maintenance cycle and relatively lower maintenance costs. However, the Overhung Single - Stage Double - Suction Pump (BB2) has a complex structure, especially the inspection of the flow channel and bearing system is more difficult, requiring operation by professional technicians. It has a longer maintenance cycle and higher overall maintenance costs than the former.
In terms of procurement cost, the Overhung Single - Stage Single - Suction Pump (BB1) has lower manufacturing costs and a more affordable equipment procurement price. The Overhung Single - Stage Double - Suction Pump (BB2) has higher manufacturing costs and a relatively higher procurement price due to its more complex design and processing technology.
To sum up, the differences between the Overhung Single - Stage Single - Suction Pump (BB1) and the Overhung Single - Stage Double - Suction Pump (BB2) cover multiple dimensions such as structure, performance, application, and cost. In actual selection, it is necessary to comprehensively evaluate and select a more suitable pump type based on specific conveying requirements, working conditions, and cost budgets to ensure the efficient and stable operation of the centrifugal pump system. With a professional technical team and rich project experience, TEFFIKO Company deeply considers the details of working conditions and comprehensively weighs the structural, performance, and cost factors of pumps in each product recommendation and system construction. Choosing TEFFIKO means choosing the most professional and considerate partner in the field of centrifugal pump application. Please feel free to contact us if you have any needs.
