1. The sanitary negative pressure pump marks the efficiency of the centrifugal pump and reflects the utilization of the power machine by the centrifugal pump. It is usually represented by the symbol η, and its height is measured by %. If the various loss powers in the pump are relatively small, then the efficiency of the pump is high, and the required shaft power is small; on the contrary, when the various loss powers in the pump are relatively large, the efficiency of the pump is low, and the required shaft The power is large, indicating that the quality of this pump is poor and the matching is unreasonable. It can be seen that efficiency is a very important technical and economic indicator to measure the performance of a pump. The efficiency indicated on the nameplate refers to the highest efficiency that this pump can achieve when running at the rated speed.
2. The rotational speed of the sanitary negative pressure pump refers to the number of revolutions per minute of the impeller of the water pump, which is represented by the symbol n, and its unit is revolutions per minute. The water pump is designed, manufactured and operated according to a certain speed. When the speed changes, other working parameters will change accordingly. Therefore, the speed is an important technical index that determines the performance of the pump. The speed marked on the nameplate of the pump refers to the speed of the pump at the highest efficiency, which is called the rated speed. The corresponding marked flow, head, power and other parameters refer to the performance of the pump running at the rated speed.
3. Allow suction up to the vacuum height. It indicates the water absorption performance of the sanitary pump and is used to determine the installation height of the pump. It is represented by the symbol Hs and its unit is meter. It should be pointed out that the Hs indicated on the nameplate refers to the maximum suction lift of the pump itself, and it does not consider the loss of the suction pipe head. In the centrifugal pump series, Hs=2.5-8.5 meters. Within this range, each pump has its own allowable value. If it is exceeded during installation, the pump will not be able to pump water.
It can be seen that after we correctly understand the performance parameters of the water pump, we can choose and use the water pump reasonably.