Not often one gets to mix these topics into one question, but the principle applies to all of the above. If I decrease my pipe diameter, does the pressure increase or does the flow rate increase?
My well pipe is leaking between the house & the well. It is 1 1/4" ID pipe, so I shoved a 3/4" ID pipe through it & connected it to the 1" pipe coming from up the well. I know I had 60 psi peek in the 1 1/4" pipe, but what will the pressure be in the 3/4" pipe? I bought 100 psi potable water poly-pipe, so I hope I am on the safe side.