I finally finished my repipe. It took 3 1/2 days, and I moved the water heater outside. Everything turned out fine, except for the water pressure when the backyard spigot is turned on. Prior to the repipe I couldn't shower and water grass at the same time because the spigot was tied into the same line with the potable water. My setup in front of the house consists of 2 cold water lines coming in. 1 comes in 3/4 going straight back the spigot, and the other goes through the regulator and feeds the house. After I finished up, I hooked up a gauge and I have it set to 80 psi, but when I turn on the backyard spigot, it drops to 40 psi. Why is this happening?