# if i install 1/2" water pipe, as a branch----

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by bsa_bob, Jul 17, 2011.

1. ### bsa_bobDIY Member

Joined:
Jan 11, 2011
Location:
britton mich
in 25 feet, will i get the same amount of water,coming out, as i would a 3/4" pipe serving the 1/2" o/s spiggot. This hard water line is backed up off the main by a 35 foot of 3/4"copper. I seem to have less pressure in my hard water line.
? I have a soft and a hard water next to each other /front of house and in back.

What i'm trying to say the lines are 25 feet off a 3/4" main.both are 1/2" i think the hard water line should probably be 3"4" I s this the right thinking?? thanks for any of your time bob s

2. ### Gary SwartIn the Trades

Joined:
Sep 1, 2004
Location:
Yakima WA
I believe you are confusing pressure with volume or flow. Given equal pressure, you will get more volume of water out of the 3/4" pipe. (Area = Pi x radius squared) Do the math for the two pipes and you will see there is much more area in a 3/4" pipe than a 1/2" pipe. The only way to tell for sure what your pressure is is to use a pressure gauge. Pressure does not change with the diameter of a pipe. Over extreme distance you would have pressure loss because of friction, but it would be insignificant on the distance you are concerned with.

4. ### jimboPlumber

Joined:
Aug 31, 2004
Location:
San Diego
There is always psi loss due to friction when water flows through a pipe. A larger diameter pipe has LESS loss. The psi loss increases with volume of flow.

In your situation, the difference would be slightly noticeable, but not extreme.

5. ### hjModerator & Master PlumberStaff Member

Joined:
Aug 31, 2004
Occupation:
Plumber
Location:
Cave Creek, Arizona
Your faucet, whether 1/2" or 3/4" will have the same 1/4" opening in it, therefore the difference in flow between the two sizes for that length will be insignificant.

6. ### bsa_bobDIY Member

Joined:
Jan 11, 2011
Location:
britton mich
I hadn't realized how much of this plumbing stuff i have forgotten!! Thanks HJ and all who posted help for me bob s