1. The lift distance is the vertical distance from the liquid level to the flange center of the pump inlet, which refers to the energy difference between the liquid inlet and outlet of the unit mass. Specific example: If it is an ordinary clear water pump, the lift of the pump is 50 meters. Actually 50 meters minus the loss along the path and the local loss value of the pipeline line is the distance value from the liquid level of the pump suction tank to the lift height.
2. Line pipe losses include loss along the route and local loss of the line. The loss along the path is related to the material of the pipe, the size of the pipe diameter, the flow rate and the viscosity of the transmission medium; the local loss mainly refers to the losses caused by the tapering pipe, bent pipe, and various valves. The two loss algorithms can refer to the related fluid mechanics. books. In the actual calculation, the local loss is relatively small and can be roughly estimated. The general headings on the general centrifugal pump product catalog are taken from the average estimate of each manufacturer, and the actual application is combined with actual field scientific analysis in different occasions. Here is not an example.
3. For general centrifugal pumps, the head will decrease as the pump flow increases. This is the characteristic of the pump itself. For pipeline systems, the greater the flow delivered, the higher the required lift. The characteristics of the pump and the characteristics of the pipeline will have a balance point (professional point of view is the intersection of the characteristic curve of the pump and the characteristic curve of the pipeline), which is the operating point of the pump. When selecting a type, the required lift is calculated based on the flow rate delivered by the pipeline. A suitable pump type is selected according to the conditions of the medium, flow, and lift, and the shaft seal, material, and supporting motor of the pump, etc. are selected.
