underground water lines, what size plumbing

[v8only]

Hey all,

So i have 4 acres and i want to add some hose bibs to the perimeter of my property to allow for easier watering. I have attached a drawing with my property dimensions and approximate location of the hose bib coming from the house.

What i would like to do is:

the 1/2" line from the house into a manifold that would feed 1 100' rubber hose, run out directly to the north 100' to one hose bib have a "X" connection in this line and run out east and west to the other hose bibs. I will not be running all the lines at the same time at most i would run 2 at full blast to run sprinklers.

What size line should the underground lines be to ensure i have adequate pressure? can my current water pressure in my home handle this extra load? what size manifold should i make?

thanks.

[wrooster]

the 1/2" line from the house into a manifold that would feed 1 100' rubber hose, run out directly to the north 100' to one hose bib have a "X" connection in this line and run out east and west to the other hose bibs. I will not be running all the lines at the same time at most i would run 2 at full blast to run sprinklers.

The 1/2" line is going to be your flow limitation. Can you run 3/4" or better yet 1" out of the house to the manifold?

What size line should the underground lines be to ensure i have adequate pressure?

See below.

can my current water pressure in my home handle this extra load?

There are two aspects to this -- pressure and volume. Where does your water come from? Well or city? If on a well, what PSI @ what GPM did your driller/pump installer end up documenting? If city water, what size is the main and what is the typical pressure?

The short story here is that you could run a 12" main out to your spigots but you need to first determine whether you can actually source the water at the pressure/flow rate you need.

what size manifold should i make?

See above. But in general, for the distances you are running, it will have to be AT LEAST 3/4" and better 1"

Wrooster

[v8only]

The 1/2" line is going to be your flow limitation. Can you run 3/4" or better yet 1" out of the house to the manifold?Wrooster

Yes i should be able to.

There are two aspects to this -- pressure and volume. Where does your water come from? Well or city? If on a well, what PSI @ what GPM did your driller/pump installer end up documenting? If city water, what size is the main and what is the typical pressure?

The short story here is that you could run a 12" main out to your spigots but you need to first determine whether you can actually source the water at the pressure/flow rate you need.

But in general, for the distances you are running, it will have to be AT LEAST 3/4" and better 1"

Wrooster

I am on a well system, i am not sure what PSI @ GPM i a rated do you know where i can find that info? will it be on my pump or water softner?

So you are saying in order to get adequate pressure to my hose bibs i will need to have a 1" line to my manifold and use 3/4" line out to the hose bibs? or can i use 1/2" out to the hose bibs?

[aczlan]

So you are saying in order to get adequate pressure to my hose bibs i will need to have a 1" line to my manifold and use 3/4" line out to the hose bibs? or can i use 1/2" out to the hose bibs?

I would use 1" throughout... It will probably cost you a little extra, but IMO it is worth it. We have one hose with a 3/4 feed line and one with a 1" feed line and when you open it up you know which you are using.


Aaron Z

[v8only]

To make things a bit easier would i be able to use my 1/2" line out of the hose into a 1" manifold then 1" throughout?

Would the 1/2" line inside the house make enough of a bottle neck that it would slow my flow?

[aczlan]

To make things a bit easier would i be able to use my 1/2" line out of the hose into a 1" manifold then 1" throughout?
Would the 1/2" line inside the house make enough of a bottle neck that it would slow my flow?

How much work will it be to change the 1/2" now now vs down the road? 1/2" copper will flow water at 3.2GPM while 1" poly pipe can handle 12-18 GPM (depending on the pressure). That will be quite a bit of difference when you open the hydrant let me tell you.

Aaron Z

[v8only]

alright you convinced me.

I will do 1" throughout im just being lazy and trying to save a few bucks.

What type of line should i buy? is there a certain PSI i should look for? or am i ok with any type of pex.

[aczlan]

alright you convinced me.
I will do 1" throughout im just being lazy and trying to save a few bucks.
What type of line should i buy? is there a certain PSI i should look for? or am i ok with any type of pex.

I would use the black poly pipe. Available in large rolls (up to 500' or so) at your local plumbing supply store with pressure ratings from 120PSI up to 200PSI.
I like 200PSI pipe because while it costs more than the thinner stuff, the price difference isn't enough to be worth my time to dig it back up in a couple of years when the thinner stuff fails.
One note, when putting fittings on, a propane torch works wonders to soften the end of the pipe and make the fitting go on easily.

Aaron Z

[wrooster]

I would use the black poly pipe. Available in large rolls (up to 500' or so) at your local plumbing supply store with pressure ratings from 120PSI up to 200PSI.
I like 200PSI pipe because while it costs more than the thinner stuff, the price difference isn't enough to be worth my time to dig it back up in a couple of years when the thinner stuff fails.

^^^ This!

Wrooster

[J_J]

You could also do 1 in thin or thick wall PVC and blue glue. Thin wall will flow more water.

To measure what your pump flow is, take a 5 gal bucket and fill it up.

5 gal - 60 sec = 5 GPM

5 gal - 30 sec = 10 GPM

5 gal - 15 sec = 20 GPM

If you look in the outlet of your spigot, you may only have a 3/8 hole in it.

A 1 in gate valve from pump flowing into a bucket ,

A 1 in solenoid sprinkler valve would work fine. It also has manual control. A transformer and switch will work. A sprinkler timer will make it automatic.

You can even use your computer to set and control the timing, and on /off cycles.

The orifice in the sprinkler head and GPM and pressure will dictate the area covered.

Are you trying to get complete coverage.

Do you want to be moving hoses or sit back and let the system work for you? Early morning hours is the best time to wet the ground.

My knees hurt now from all the working I have done on sprinkler systems. I still have my trenchers and valve clickers and wire locators.