Assume you have a horizontally placed cylindrical pipe with constant diameter. There is a flow of water, through this pipe. You want to measure the static pressure inside the tube, which should be the same everywhere along the tube if we assume there are no pressure losses due to friction. On the top of the pipe, two vertical measuring tubes are placed to measure the static pressure in these two places. But like we said, the static pressure should be the same in both places. The two measuring tubes have different diameter, where the second one has twice the diameter of the first. Will the height of the water column in the measuring tube with the larger diameter be half that of the other? If so, how could you conclude that the static pressure in both places is still the same?