PEX v Polyethylene Tubing for 800 foot Water Supply Line

[Kimberly G]

We are trying to decide between PEX and PE tubing for an 800 foot water supply line and cost is of course a factor. Will be using directional boring to cross our neighbor's property and two hundred feet is maximum for a pull, so longer PE pipe availability isn’t really a factor. The run is nearly level, maybe drops 15 feet overall and has two turns. The ground isn’t rocky and over time could be more fir tree roots, however we expect very little use of the easement areas by our neighbors. I think we need a minimum 1.5” internal diameter pipe to account for pressure loss over distance but 2” CPS PEX is spendy and we’re not sure it’s worth it. It seems PEX would be best, but would it be unreasonably risky to use PE? Also, we are even considering perhaps PEX with 1.25” internal diameter or less, and then using an booster pump system at the house if there are problems.

Other info: 65 psi at the meter and setting a ¾” meter for a new 3 bedroom 2.5 bath house with low flow fixtures; using a cistern/low flow well for outside watering. The local PUD has a $3,000 price differential between a 3/4” and 1” meter so we really don’t want to step up to 1”.

Thank you for considering this question.

 

[Reach4]

http://www.pressure-drop.com/Online-Calculator/ is a nice calculator. You have to work to get the units right.

The pressure drops add. Figure about 10 gpm for the house, unless you have another number you want to use.

I would go for SIDR polyethylene pipe.

http://www.charlottepipe.com/Documents/PL_Tech_Man/ExpansionandContraction.pdf
https://www.huduser.gov/portal/publications/pex_design_guide.pdf

Read about thermal effects. Essentially, don't pull the pipe tight; let the path snake some. I am not a pro.

 

[Sponsor]

 

[Kimberly G]

Read about thermal effects. Essentially, don't pull the pipe tight; let the path snake some. I am not a pro.[/QUOTE]

Thanks for comment re thermal effects, good to discuss with the directional driller along with not pulling the pipe too tight. But maybe won't be so much change in temperature if run 3-4 feet underground in December.