Re: water supply pipe size
Posted by Gary Slusser on January 19, 2003 at 16:39:20:
In response to Re: water supply pipe size
: We are replumbing an old house that has 3/4" copper from the street (about 30 feet to the meter).

: Total planned fixture units is 37 (3.5 baths plus hoses etc.).

: Current meter is 3/4" x 3/4".

: Is seems that we can change the meter to 3/4" (street side) by 1.25" and run 1.25 copper type L as long as we can in the house before we branch.

: Also, does required anti-backflow valve and pressure reducer valve need to have 1.25" fittings to maintain flow/velocity etc. or can they be smaller?

: Thank you in advance for any help.

: Adam

In my opinion, you want K copper (underground) and it should be in a conduit if you�re going to use copper and I�ll suggest using polyethylene instead. New NSF 61 says no copper if the water pH is <6.5 anyway. I would use PEX inside if allowed. It goes in much faster than copper and is ideal for what you�re doing.

As to the size, I�d have to look it up but, the �� meter restriction will cause a pressure loss but calculate that in and go from there. Here�s a URL
for PE tubing losses and it has fitting losses too although copper losses may be just slightly higher. I don�t know about the PR and anti backflow, I�m not a plumber.

Replies to this post