I'm starting a project involving a venturi and water, and for the venturi, I need the water pressure to be around 7-10 psi. This means for my water pump, the head height must be around 15-20 ft. Most pumps that fulfill this requirement are either too expensive or are too powerful for my application. I'm looking for a 300-500 gph pump that can give me the 7 psi (most pumps are in the thousands of gph by this point, or are hundreds of dollars). I'm wondering if there is a way to convert flow (gph) into psi (head height) by changing the shape or diameter of the piping. I know if I make the piping smaller, it will reduce pressure (Bernoulli's) but at what point would increasing the diameter of the pipe stop helping me?