Ok, so Im replacing the main water supply line at my fiance's mothers house. There had been galvanized pipe in there from lord knows how long ago. It is believed to be the original plumbing, so 70+ years old. The entire inside of the pipe was almost completely closed due to rust and sediment buildup. I asked a few people i know what i should use to replace the pipe, and got similar answers of sch 40 PVC is fine. Im in Cali, so there isnt a frost issue. I get to Lowes to ask a few final questions, and Im told by 3 different people to most definatly not use PVC as it wont be able to handle the pressure........60-80 is what I thought normal pressure for a house is, and this 3/4in PVC was rated at 480PSI. Am I wrong with going with Sch40 PVC? I picked it cause it seemed to be the easiest fix as well as quite cheap. Any info would be helpful!