How to calculate the pressure loss in centrifugal pump pipelines
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When transferring material from the stock solution tank to the equipment, when selecting a pump, if the height of the pump’s inlet is lower than the bottom level of the stock solution tank, and the pump’s inlet is 100 meters away from the tank while its outlet is 200 meters away from the equipment, should the head loss be calculated for the entire 300-meter pipeline, or only for the 200-meter section leading from the pump’s outlet?
Calculating the cavitation margin means calculating it for the inlet
When selecting the head of a pump and calculating the losses, should the lengths of the inlet and outlet pipelines be considered together, or only the pressure loss at the outlet?
Determine the pump head based on the required inlet and outlet pressure difference
I’m not quite sure – isn’t the pressure difference between inlet and outlet the pump’s head? When selecting the head of a pump, should one first estimate an initial head based on the flow rate and site conditions to choose a pump, then roughly draw a piping layout based on the inlet and outlet diameters of the selected pump, and finally calculate the pipeline losses using this layout to determine whether the head of the chosen pump is sufficient to cover those losses. You can’t just increase the pipe diameter or upgrade the impeller size, etc
For example, the vertical height of the outlet, the inlet pressure of the downstream equipment, the length and diameter of the pipes, the type and quantity of valves, and the type and quantity of pipe fittings.
Does the pipeline length here include only the pump outlet, or does it take into account both the pump inlet and outlet pipelines?
The head of a pump is determined by the pressure difference between the inlet and outlet; the inlet pressure also needs to be taken into account, otherwise how can you know what the inlet pressure is?
A colleague told me that the pipe loss before the pump is used only to determine the allowable installation height, while to check whether the pump’s head is sufficient, it depends on whether the pipe loss in the pump’s outlet pipeline exceeds the pump’s head
Then ask other designers as well