Application scope, working conditions and characteristics of multistage pumps

Single-stage single-suction centrifugal pumps are commonly used centrifugal pumps. Although their flow range is relatively wide, their head cannot reach a high level. In places where high head is required, multi-stage pumps must be used to meet customer requirements. The head of a multi-stage pump is several times that of a single-stage pump. Today, our pump experts from HRZL Pump Manufacturing Co., Ltd. will briefly explain the use range, working conditions and characteristics of multi-stage pumps. 1. Scope of use of multistage pumps Multistage pumps are generally suitable for constant pressure, variable frequency water supply, fire fighting, and sprinkler water in high-rise buildings such as residential areas, hotels, and buildings; they can also be used for water supply equipment such as water supply pumps, pressure-stabilizing pumps, circulation pumps, remote delivery pumps, and boiler water supply in chemical plant cooling towers. The liquid that can be delivered is clean water at room temperature (less than 80 degrees Celsius) (hot water type can deliver medium with a temperature less than 105 degrees Celsius) or a room temperature medium with physical and chemical properties similar to water. 2. Working conditions of multistage pumps  （1） The medium used should be similar to water, with a kinematic viscosity of <150mm2/s, and no hard particles and no corrosive properties; （2） The environmental altitude of the pump is <1000 meters; （3） The medium use temperature is -15℃～120℃; （4） The maximum system working pressure is ≤2.5MPa; （5） The ambient temperature should be lower than 40℃ and the relative humidity should be lower than 95%. 3. Product features of multi-stage centrifugal pump for water supply （1）The pump has a compact structure, small size and beautiful appearance. Its structure determines that the installation area is small. If a protective cover is added, it can be placed outdoors for use. （2）The impeller is directly installed on the motor shaft to ensure the concentricity of the pump, thereby enhancing the operating stability of the pump and extending the service life of the pump.  （3）The shaft seal adopts mechanical seal or combination of mechanical seals, and adopts high-quality alloy sealing ring, which enhances the wear resistance of the seal and effectively prolongs the service life. （4）Easy installation and maintenance, no need to dismantle the pipeline system. The pump inlet and outlet are of the same caliber, which simplifies the connection of the pipeline.  （5）The pumps can be operated in series or parallel according to the needs of flow and head.  （6）The suction port and the discharge port can be installed in different directions of 0°, 90°, 180°, and 270° according to the needs to meet different connection occasions.