Regarding the pump’s suction issue, please ask a senior for help
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I’m facing a practical problem: the suction conditions at the pump’s inlet can be calculated without any issues. However, there is a section in the suction pipeline that is at a higher elevation. If I perform the calculations with the pump placed at the highest point, the effective net positive suction head available to the pump is not sufficient to meet its requirements (the pump requires a net positive suction head of 3.2 m), whereas the calculated value here is 3.0 m. Is there something wrong with the suction conditions for this pump?
No problem; NPSHa refers to the pump inlet, and it has nothing to do with the pipeline height
It is best to avoid using Π-shaped sections in the pump’s inlet pipeline during installation; if this cannot be avoided, an exhaust valve should be installed at the top of the Π-shaped section to prevent vacuum formation in the pump due to air accumulation in that bend.
Raising the inlet section slightly will have an effect, and increasing the length of the pipeline affects the inlet losses; however, since the length isn’t large, the impact is minimal. But for materials that vaporize easily, is the pressure at the highest point sufficient during the hot summer days? It is best not to create such piping.
I agree with this. For products that are easy to vaporize, if they are too far from the pump inlet and the temperature is high, they will vaporize. If such a situation does occur, it is recommended to cool the pipeline with water, which will make pumping easier
Yes, the main issue is that the pipes are already in conflict with each other, making it impossible to avoid the formation of π-shaped bends. The only option is to try to reduce the height of those high points, and air release valves have been installed at those locations. I’m wondering whether this will affect the pump’s ability to draw in fluid, and whether there could be problems with suction