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Discussion Starter · #1 ·
I will be having a home built soon and to save money I will be responsible for getting water to the homesite. The water main is 8" and relatively new so I am assuming good pressure. The local water company will install a meter and cut off valve but I am unsure of what size pex to use. I need to travel approx. 600 feet and then a licensed plumber will finish the project when the home is built. The problem is that I have gotten two conflicting opinions of what size pex to use. I contacted pexsupply.com and asked them and they assured me that 1" would be more than adequate but my local water company told me that they would recommend 2".

Can anyone give me some accurate data on the size I should be using for this project? If I use 2" will I need to install a regulator to reduce pressure at the homesite?

Thx
 

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1" is the size of copper pipe they used when they replaced my water service. There is a concern with smaller inner diameters with PEX fittings. It seems like the smart choice would be to follow the water company's recommendation. Ask them why they think you need to go that big though.
 

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You need to know your water pressure, elevation rise from meter to top outlet and distance to furthest fixture to properly size water. With this info you can then reference sizing charts. With the info you've supplied, I'd trust the water company
 

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Discussion Starter · #6 · (Edited)
I just called the water company and asked the question of why 2" and was told that size was recommended based on years of experience in the business. Her home was built .2 miles from the main and they recommended 2" at that time. She chose to go with 3/4" and says the her water pressure isn't that great. My home will be approx. .11 miles from the main which is just over half of that distance so 2" seems like overkill.

I also asked about pressure at the main and was told that it was approx. 65 psi.

So here is my next question...with a pressure of 65 psi and very level ground travelling 600 feet to homesite and the furthest fixture from there being approx. 100 feet away what size pex would be recommended and will I need to purchase a regulator to reduce the pressure at the homesite so I don't get blasted out of the shower?

I just checked online for a sizing chart and came up with some good info...if I did the math right. I will be building a 3 br home with a total of 31.5 fixture units(I think). Based on the chart I found and a 700 foot total length, over 60psi, 3/4" meter outlet and 31.5 fixture units it falls between 1 1/4-1 1/2".

http://www.ci.manhattan-beach.ca.us/Modules/ShowDocument.aspx?documentid=3887

Thanks for all of the help. I really appreciate it. Let me know if I calculated this right.
 

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I don’t have a code book with me but you sound good with at least 11/4. Last thing you want is inadequate flow or pressure.
You don't need a PRV until you hit 80lbs
Why pex? We use 200lb poly for service lines.
 

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Discussion Starter · #8 · (Edited)
Tell me more about the poly tubing. I have looked all over the net and keep running into brick walls. If it is cheaper than pex and meets code then I'll definitely look into it. I have found HDPE tubing but it seems to be around the same cost as pex. Are there advantages to HDPE over pex or vice versa? I assume that a local plumbing supply house will have it in stock with all the fittings I need but would like to know more about it.

Thanks again!!
 
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