My water pressure is 80 psi at the 1.5" line service entrance to the
I want to run a branch line 150' to the guest house which has clothes
washer, kitchen sink, bathroom, exterior hose bib. What size copper
pipe should I use for this 150' run for good results?
What is a good brand of pressure regulator? I want to reduce the
pressure to 50 lbs at the guest house entrance.
Thanks for any information.
Ted in So. Calif.
You wont reduce the available pressure by using a smaller pipe, you will
only reduce the available flow volume in Gallons per minute.
Static pressure will be at the 80 psi from the time you turn on the faucet
until the flow reaches a constant volume, dependant on pipe friction loss
and supply pressure--then and only then will it drop to a lower pressure at
the other end.
IOW, you will turn on the faucet and get a big spurt at 80 psi for a few
seconds, and then it will equalize at a lower pressure and flow.
To reduce pressure you would put a pressure regulator on the line, suggest
at the end of the run.
Rule of thumb pressure drops, PVC pipe (psi/100 ft):
1/2 3/4 1"
3 gpm 8.6 2.2 0.7
5 gpm 22.2 5.7 1.7
10 gpm 80.5 20.4 6.3
Copper pipe will be about 0.2 to 0.5 psi/100 ft more loss.
You could get by with 3/4" but I'd favor 1"
I would use 1 inch pipe and probably pvc schedule 40. I would not reduce the
pressure by mechanical means unless your going to be using CPVC inside. The
pressure and volume will be enough reduced by adding the 150' of pipe into
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