Normal to have great pressure drop from a full-flow faucet?

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Seiyafan

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Recently I did some major pipe work with home plumbing and I noticed that when I open the outdoor faucet (it's a full-flow 3/4'' port), the pressure at the water main (I installed a pressure gauge right at where the city water comes in to my house through 3/4'' pipe) drops to 6 psi. Normal static pressure is 50 psi and I am getting 8 GPM from the faucet, it's decent but not great. Between the water meter and this faucet there is not much restriction, and I used 1'' pipe to further minimize any potential pressure loss.
If the vast majority pressure is already dropped at the main, does this mean the main restriction to flow happens outside of my house?
 

Reach4

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Check to see that the valve for the incoming water is fully open.

I presume there is no pressure reducing valve or filter in the path.

Next would be to make sure the valve at the curb is fully open.

Did you do any work before where the pressure gauge tees off?
 

wwhitney

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If the vast majority pressure is already dropped at the main, does this mean the main restriction to flow happens outside of my house?
Reach4 has good suggestions, but the basic answer to your question is "yes". Could be an undersized lateral (how long, what material?), a pinched lateral, or some debris in the lateral.

Cheers, Wayne
 

Seiyafan

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Check to see that the valve for the incoming water is fully open.

I presume there is no pressure reducing valve or filter in the path.

Next would be to make sure the valve at the curb is fully open.

Did you do any work before where the pressure gauge tees off?

Valve is fully open, no PRV and filter in the path, I didn't check the valve at the curb but the town people did touch it in the spring when I had the main valve replaced, so I presume they would open it fully. The pressure gauge was added last week when I completed this project so no work was done before that.
 

Reach4

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the pressure at the water main (I installed a pressure gauge right at where the city water comes in to my house through 3/4'' pipe) drops to 6 psi.
Galvanized or copper?

http://www.pressure-drop.com/Online-Calculator/ is a pressure drop calculator. It's not that easy to use. Make sure you are using the right units. Roughness is the hardest to estimate. Click the little book icon to get some suggestions, and maybe use the pessimistic "intensely incrusted 2.0 - 4.0 mm" number in this case.

You are getting a 42 psi pressure drop at 8 gpm.
 
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