I have a simple pipe (with water) that reduces in diameter. I've been trying to calculate the pressure after the reduction using the first version of the Bernouli equation shown here; http://en.wikipedia.org/wiki/Bernoulli's_principle Now to calculate the velocity I've replaced the v with flow/area in the equation. I was expecting to see an increase in pressure after the reduction in pipe size, but the equation tells me it has actually dropped...? I'm just relating to the fact that if you squeze a hose the pressure increases, doesn't it? And I'm thinking that the flow needs to be the same before and after the reduction?