Water pump specifications and performance

The specifications of the water pump indicate the performance of the water pump,it's also the basis for pump selection and flow adjustment.

 

  1. Centrifugal pump

 

The liquid fills the pump casing, the impeller rotates at a high speed, and the liquid produces high speed under the action of centrifugal force. The high speed liquid passes through the gradually enlarged pump casing, and the dynamic pressure head is transformed into a static pressure head. Attention should be paid to prevent the occurrence of cavitation and gas binding.

 

Performance characteristics

 

The flow range of the centrifugal pump is wide, and the flow rate and pressure are stable and there is no fluctuation.

 

The centrifugal pump has a high number of revolutions and can be directly connected with the electric motor and the steam turbine, the transmission mechanism is simple and compact.

 

The operation is convenient and reliable, adjustment and maintenance are easy, and it is easy to realize automation and remote operation.

 

Compared with the reciprocating pump of the same index, centrifugal pump has simple and compact structure, small size, light weight, fewer parts, convenient manufacture, low cost, and small floor space, so the pump cost and repair cost are lower.

 

Centrifugal pumps have the following main disadvantages

 

Under normal circumstances, before starting the centrifugal pump, user need to fill the pump or use a vacuum pump to extract the air from the pump. Although the self-priming centrifugal pump does not need to be primed before running, there are still limitations in its current use.

 

The viscosity of the liquid has a greater impact on the performance of the pump. When the viscosity of the liquid increases, the flow rate, head, suction and efficiency of the pump will be significantly reduced.

 

The application of centrifugal pumps under the condition of small flow rate and high head is subject to certain restrictions. Because the flow passage of the pump body of the small flow rate centrifugal pump is very narrow, it is difficult to manufacture, and the efficiency is lower.

 

  1. Multistage centrifugal pump

 

It is equivalent to multiple centrifugal pumps connected in series with multi stages boosting to obtain higher pressure head.

 

Performance characteristics

 

Compared with single-stage pumps, multi-stage centrifugal pumps differs in that they have more than two impellers, which can absorb and press water in multiple stages, so as to lift the water to a very high position. The head can be adjusted according to increase or decrease the number of pump impeller as needed.

 

Multi-stage pumps are mainly used for mine drainage, urban and factory water supply. Agricultural irrigation is rarely used. It is only suitable for high-head, small-flow rate high-mountainous water pumping to solve the difficulty of drinking water for humans and animals.

 

There are two types of multi-stage centrifugal pumps: vertical and horizontal. The pump shaft of the multi-stage centrifugal pump is equipped with two impellers connected in series.

Compared with the general single-stage centrifugal pump, it can also achieve a higher head. Compared with reciprocating pumps such as piston pumps and diaphragm pumps, it can also pump larger flow rate. Multi-stage centrifugal pumps have high efficiency and can meet the needs of high head and high-flow rate conditions. They are widely used in petrochemical, chemical, electric power, construction, fire fighting and other industries.

 

Due to its own particularity, compared with single-stage centrifugal pumps, multi-stage centrifugal pumps have different and higher technical requirements in terms of design, use, maintenance and repair.

It is often user's negligence or inadequate consideration in some details that make the multi-stage centrifugal pump frequently wear out, vibration, shaft holding and other failures after running, and also cause shut down.

 

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