Water line trench

[BeezFun]

Calculator shows for 5gpm flow, 170', plastic pipe:
1/2" id pipe: 41psi pressure drop (1/2" actual size, not nominal)
3/4" id pipe: 5.8psi drop
1" id pipe: 1.4psi drop

So that means if you have a normal 40-60 well pressure switch, with 1/2" pipe you'll have basically no flow at the bottom side of the pressure cycle. Not sure why you want to use pex instead of polyethylene tubing, it's cheaper and used all the time. I'd use the 200psi instead of 100psi rated stuff, it's a little thicker wall and stands up better to rocks and abuse. The fittings for poly are cheaper than pex too. I went with 1" poly out to my barn.

 

[cmyoung2]

BeezFun is correct. Go bigger. It is hard to get too big of a water line. Too small and you will have issues, especially if you actually need some water flow at the end. Not only do you reduce pressure, you also reduce possible water flow, so if you ever hook up to something that need some water, like a pressure washer of a sprinkler, you are out of luck.
Also, bury the line as deep as the rented trencher(only way to go) will go. And when I went to the barn, or anywhere else, I drop a power and phone line in also. If you go too shallow, it can freeze, but more than likely, that is where you put a fence post, or plant a tree, or do something else after you forgot where the line really is. Don't know how, but they will move and end up somewhere you never imagined. (don't ask how we know these things)

 

[MoMower]

Over winter I re plumbed my whole house with Pex, using a valve board. This will be a "home run" installation, no fittings, etc between board and hydrant. I ordered a 300' foot roll of 1/2, will attempt to change that to 3/4 if I can. This line is for filling horse water trough and chicken water. Currently there is a shallow 5/8 black plastic line that is not usable in winter that I am replacing and flow is not an issue. Thanks for everyone's input.

Sent from my idrankthekoolaid device c/o TractorByNet

 

[BeezFun]

You might want to put a water hammer arrestor at the end of the line, even though you shouldn't need it with a hand operated hydrant valve. I had some spring actuated horse waterers at the end of my line and it sent a hammer back through the house that scared the dogs. I had to dig up the end of the line and add them. I put in two, that way if one fails you still have protection. The purchase price is tiny compared to digging the whole thing up again.

 

[Cord]

If you have decent water pressure at the house, a half in line should be fine. The wonderful thing about PEX is that it can freeze and it wont rupture like other lines will, so you should be fine at just a few feet. If you can drive over the ditch after you dig it, you should be fine compacting the soil with your tires driving in the ditch. Problem with a trencher is the trench is so narrow, it's impossible to compact and you are always adding dirt to it over time as it settles. I have a trencher and love it because of how quickly I can dig a trench. I hate that after it's all said and done, months later, that I find spots where I need to add dirt.

Eddie

Remember, pex is a reduced diameter from 1/2" copper. With 1/2" pex over that distance the line will be almost unusable. If the OP wanted a stock tank with a float valve, then he'd be Ok. To water grass or fill a bucket? Forget it. I ran a 1-1/4" line 180' to my barn and there is still a noticeable pressure loss.

Here in Wisconsin, the rule of thumb is to bury water lines down 72". Shallower if you plan on draining them. I know that this past winter municipal lines were freezing at 84". That said, my old house had a water line off the well at 24" deep. I put 4" of rigid insulation over the line and it didn't freeze.

 

[davehowell]

I am puzzled by several of these responses and wonder if they are based on real and personal experience. We have two runs of 1/2 inch Pex, Wirsbo/Upenor. (I am told that there are several different kinds of Pex, but do not think that one is better than any other in terms of pressure loss ). One run is to a barn hydrant is 150 feet, and the other is 200 feet to a hydrant near our goat shed. At 65 pound pressure at the expansion tank, both have plenty of flow and pressure for our purposes. Pressure and volume are sufficient to run impact sprinklers (one at a time) that we use to irrigate our 2 acre pasture. We use the hydrants for with hoses to the sprinkers and to fill stock tanks, no seeming loss of flow. Larger diameter piping is always better, but 1/2 inch pex for us has been fine.

 

[EddieWalker]

I am puzzled by several of these responses and wonder if they are based on real and personal experience. We have two runs of 1/2 inch Pex, Wirsbo/Upenor. (I am told that there are several different kinds of Pex, but do not think that one is better than any other in terms of pressure loss ). One run is to a barn hydrant is 150 feet, and the other is 200 feet to a hydrant near our goat shed. At 65 pound pressure at the expansion tank, both have plenty of flow and pressure for our purposes. Pressure and volume are sufficient to run impact sprinklers (one at a time) that we use to irrigate our 2 acre pasture. We use the hydrants for with hoses to the sprinkers and to fill stock tanks, no seeming loss of flow. Larger diameter piping is always better, but 1/2 inch pex for us has been fine.

I agree. Seems like there are a lot of examples of those who like to use bigger pipes and are happy with them, but nobody who has used the same sized pipe. I'm not a fan of spending more money for something that I cannot notice the difference by spending more money. Reminds me of a buddy that I used to bike ride with. He spent $600 for a seat that was 2 oz lighter then what he had before. He was still the last one there. Spending more without any noticeable improvement is always something I try to shy away from.

How many houses have a 5/8 inch tap? Tens of millions. I wouldn't think twice about running a half in line several hundred feet.

Eddie

 

[Ken45101]

I am puzzled by several of these responses and wonder if they are based on real and personal experience. We have two runs of 1/2 inch Pex, Wirsbo/Upenor. (I am told that there are several different kinds of Pex, but do not think that one is better than any other in terms of pressure loss ). One run is to a barn hydrant is 150 feet, and the other is 200 feet to a hydrant near our goat shed. At 65 pound pressure at the expansion tank, both have plenty of flow and pressure for our purposes. Pressure and volume are sufficient to run impact sprinklers (one at a time) that we use to irrigate our 2 acre pasture. We use the hydrants for with hoses to the sprinkers and to fill stock tanks, no seeming loss of flow. Larger diameter piping is always better, but 1/2 inch pex for us has been fine.

Well I certainly can tell the difference in the time to fill a 100 gallon stock tank with a 5' piece of half inch hose, and the much longer it takes to fill it from a 40' length of half inch hose. IIRC, we ran 1" line (ID) to the barn and I'm glad we didn't run anything smaller.

 

[ultrarunner]

How many houses have a 5/8 inch tap? Tens of millions. I wouldn't think twice about running a half in line several hundred feet.

Eddie

A lot of the 1920's homes around here still have 1/2 galvanized pipe from the meter... I've changed out just about all of mine to 3/4 copper... not because of flow... only because they generally start to leak at 70 years... like some people I know...

 

[BeezFun]

...both have plenty of flow and pressure for our purposes.

It would be interesting to quantify that, maybe take a 5gal bucket and time how long it takes to fill it. Flow charts show for 200' of 1/2" pex a 61psi drop @5gpm and a 3psi drop @1gpm. So that would say it shouldn't produce more than a few gpm.

I did tests with hose before I put in my line. 1/2" garden hose is slightly larger than 1/2" pex. I ran 200' of hose out to my barn and it looked like an 80 year old guy with prostate problems trying to take a wiz when I turned on the water.