Let's say we have water flowing in a pipe under so and so pressure at a given point. Now the water flows through bends, turns and straight lines of pipe. Will the pressure after a distance be lower than it was at the starting point, due to friction in the pipes and bends and such? Or will the pressure be constant at all points? The pipe dimension is constant. I'm asking 'cause we're learning about radioators in houses, and the fact that one must account for what I can translate to mean "pressure drop" as the water flows through the system. I'm just having a bit of trouble believing that the pressure is different at different locations in the system. If we measure 3 bars just after the pump, won't the pressure be 3 bars everywhere in the system...? Secondly I wonder about this; if we place water in a pipe at let's say 2 bars, does that mean that we have pushed more water into the pipe than there's actually room for? In other words; have we compressed the water? I didn't think that was possible...? I'm confused, please someone help me!