Water Main line

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RonFromSeattle

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I am a homeowner looking to replace my water main line, and in the process move where it enters the house from the back to the front.
I was thinking of using PEX. Is 1" the preferred size?

Also can the PEX pipe enter the house through the basement concrete wall? Or does it need to be copper as it passes through the concrete wall?

Also, how do I connect the PEX to the city connection? Some sort of compression fitting?

Thanks.
 

Jadnashua

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FWIW, 1" pex would probably not meet current codes as it's likely too small of an ID. As to its suitability, not sure. Some places want a tracer wire on/in/around the plastic pipe so that it can be found prior to a dig, so take that into consideration, too.

While you may be able to legally run a new line, I seriously doubt your locale allows an unlicensed homeowner to touch the main line. After the demarcation line of ownership, yes (in many places), so it would depend on where you needed to connect the new line.
 

RonFromSeattle

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Thanks for the response, but looks like it's different out West here.
Checking through old threads I see than many plumbers have used 1" PEX in Seattle for the main line. Some use 1 1/4" though.
As for an unlicensed homeowner replacing their own mainline, it is okay to do in Seattle. I replaced the mainline for my last house, 5 years ago. And I used PEX, and the city inspected, and passed it.

My main questions remain as to the connection to the meter, and how best to enter though the foundation wall. (When I did my previous main line, I had a problem connecting to the meter, and had to call a plumber out for that.)
 

Terry

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Many of the meters there have 3/4" female that will take 3/4" MIP thread.
For a two bath home in Seattle, you will want a 1" line.
 
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Jadnashua

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The meter can be considered a short length restriction. Those do not restrict the flow all that much like a long length of smaller ID pipe will. The ID of 1" pex is closer to the ID of 3/4" copper. Most larger homes will want more to maintain flow and pressure as high as it can be.

With PEX, you don't have all that many choices...you could use a compression fitting with the appropriate internal stiffener, or a crimped connector. Pex cannot be exposed to UV rays, so depending on where in the foundation it comes through, that may change your plans.
 

RonFromSeattle

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Thanks for the comments.
My main line run will be 35 feet to the house (underground).
I have a 3 bed, 2 bath house, with a second small kitchen in the basement.
Currently my water pressure is 90 psi with the original galvanized pipe that looks 3/4 to me.
I was going to add a pressure regulator when I changed out the main line.
So I am thinking 1" PEX will work for me for that mainline?
 

Reach4

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http://www.seattle.gov/util/Enginee...terService/InstallationRequirements/index.htm has some info for you. I first thought it would permit PEX or other plastic through the wall through a sleeve, but I now think it is saying that you would need to transition to type K or L copper with 2 ft before the foundation. Type K is the better/heavier stuff.

Part of the considerations would be how long the run is, and what the water pressure in your area tends to be. If you need a PRV in the house, you could run farther and longer with a given size of pipe. If the city water is about 50 PSI in your area, I would tend to opt for bigger pipe.

I would tend toward HDPE for a longer run. It is cheaper than PEX, and it has a larger diameter for a given nominal size.
 
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Jadnashua

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There are tables that will tell you the maximum design volume for any particular type and size of piping. Note, static pressure would be fine with even a 1/4" pipe...you want to be able to maintain the pressure with minimum losses due to friction during the flow at maximum. The smaller the pipe and the higher the volume, the greater the friction which exhibits itself as a loss in dynamic pressure as opposed to static pressure with no flow.

There are also codes that dictate the size of the water supply pipe, and I do not think 1" pex would pass in your area...it should be easy to call the local inspector's office and find out. It does not hurt to use a larger pipe in case you might want to add a sprinkler system or add a bathroom, or be ready for that long weekend with guests and everything is running at the same time. It's nice to get good flow without issues! The smaller water meter isn't a major factor at your supply pressure because it is so short.
 

RonFromSeattle

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Thanks for the comments, Reach4 and jadnashua. I will call the city inspector and get an opinion. And I do read the code as requiring the pipe transition to copper before going through the wall.
 

Cacher_Chick

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The primary issues I would consider regarding pipe size is first that PEX has a smaller I.D. than the equivalent galvanized or copper pipe size, not to forget that each fitting inserted into the PEX piping system is also of a smaller I.D., and causing even more of a reduction in flow.
A single bath home is commonly piped in 3/4" copper tube size, and a double bath in 1" CTS. If there is any thought of irrigation in the future, the line should be sized with that added into the equation.

It is common knowledge that when PEX is used, best practice is to install one size larger than the equivalent CTS calculation.
 

Dj2

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I would use Copper L, with 2" sand under the pipe and 2" sand over the pipe.
3/4" pipe will be fine.
 
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