I don't understand the ideas behind the continuity equation when applied to a vertical pipe. In all the questions I see regarding a vertical pipe of constant diameter, I see that the fluid's velocity will remain constant while travelling through the pipe. Common sense will tell you this isn't true despite what the formula tells you. The fluid will accelerate because of gravity, giving it a different velocity the further you go down the pipe. I'm well aware of the two assumptions required for the continuity equation : 1. Steady Flow and 2. Incompressible liquid - and I'm sure this isn't relevant to any acceleration due to gravity. Can someone please explain this? Thanks for the help!