If I have 80 lbs pressure then run water through a 1/4 inch pipe how many pounds pressure do you think is on that side?
We are talking about volume the GPM flow through the pipe. If his galvanized is rusting shut he may still have water to serve 1 fixture at a time. He may still read 60 lbs pressure when not using anything. His problem arises because when he runs 2 fixtures his piping does not allow the GPM flow he needs. He may also have an entire house stuff full of 1/2 inch only water lines for all I know.
A larger pipe allows more GPM out. Static pressure shows nothing in regards to flow rate. In some areas the water providers do that 1/2 inch meter thing here all the time. The houses experience no problems. I'm not saying I agree with them on this but it does work.
Last edited by Ghostmaker; 01-20-2014 at 06:36 PM.