TedI know what your thinking, but its wrong. I saw the design and operation of service lines this size in a network that served over 25 000 people. Not only were the designs very economical, proffessional and accurate, they were also designed by people with more education than me and you put together.In one sentance you say The most water that will flow through this line is what the area will allow at a given pressure. This works to prove my point and half of yours. The real proof behind what I say is: Flow = area x velocity What the area will allow is what velocity and flow will give when a line is running full at a fixed speed.A large change in pipe diameter will increase pressure on the point of diameter change and possibly more if the network is weak. This is a basic flow priciple for any incompressible liquid. Any hydraulic engineer would learn this in their first week. The proof is: Flow = Velocity1 x Area1 = Velocity2 x Area2 The 1 and 2 represent velocities and areas of two different pipe sizes.When one pipe diameter changes the flow is limited by that change. So when area changes, velocity and flow change. Velocity will increase therefor pressure will increase and flow will remain the same.Now put your numbers into this equation. See what the pressure change from a 2inch line to a 1/4inch line is. Now try it for a 12inch line to a 1inch line. Is this increased pressure necessary for a single family dwelling or is the differance so small that there is no point. Try it, I have.I hope you see my point. Although your approach is great in a Tim the Toolman, more power to ya type of way, it often results in oversized lines and wasted resources.Unless the pump can not overcome the head to provide adequate pressure for multiple open outlets (it should if sized properly) a change of line size from outside to inside is completely unnecessary.
