Trenching Water Line...

Quick question:

This week I am planning to run black polyethylene water line out to barn and pastures from the house.

Will be starting from a 3/4" copper line from the pressure tank in the basement (& installing a shutoff valve), then go through the basement wall, and then trenched 3 ft deep all the way out to the barn.

Longest run is a good 550 ft. or so.

QUESTION: What diameter of polyethylene to use? 3/4"? 1"?

Fyi, there's 1" black poly from the well to the pressure tank in the basement of the house, then from the pressure tank to the spot where I can tee off from is 3/4 copper. The hydrants themselves are 3/4" diameter inlet.

Is there ANY benefit trenching 1" poly over 3/4" if both the source and the destination are essentially 3/4"???

Will my water troughs fill up any faster?

Thanks!

You didn't say how much water you need or what your using it for. That makes the difference. The friction loss goes up as the gallons per minute go up.

bob...

Change the 3/4" copper to 1" sch 40 PVC, or 1" PE, or 1" copper from the pressure tank tee to where you want to tee off to the barn.

And then run 1" the 550' and tee 3/4" off it to each hydrant. Otherwise the friction loss will reduce flow. And you may have to increase the pressure switch settings (and air pressure in the tank) on the well pump; especially if the 550' goes up hill.

You want a 1" shut off valve and then a 1" check valve on the line to the barn.