Couple of yard hydrant questions

[Finch85]

Good morning,

I'm installing a mini-split on my garage and I need to dig a trench to run power. In order to capitalize on my trencher rental, I was planning a few "side projects" while the trencher is in my possession. One of those projects is installing one or two yard hydrants in the backyard. I have 1 inch poly running from my well to the pressure tank located inside my home. I would like to splice into the main line a few feet from the wellhead and run two lines for yard hydrants. Please see the attached screenshot for reference.

I've read that I should be fine teeing off from the main line to install a hydrant if there is no check valve between the pump and pressure tank. I'm assuming there is not but I will verify. Where would this normally be? At the pressure tank?

Questions:

-Any issues with my proposed plan?
-Should I tee off with 1" poly or reduce down to 3/4" for each hydrant run?
-Shutoffs needed underground for each tap line to the hydrants? How do I keep these assessible? Would I really need some sort of box a couple feet deep down in the ground? I'm in VA with a 18" frostline I believe. I was going to put the lines down 24 inches.
-Not being tapped from the pressure tank, I assume whenever the hydrant is turned on, it is using whatever water is already in the lines. Say I'm running a lot of water from one of these hydrants, how will the well pump know when to turn on since I'm not tapped off from the pressure tank? I'm a little confused about this.

Note: If I only had to pick one hydrant to install, I'd want to to the 75' run since its closest to my driveway.

Thanks,
Donnie

- Do

 

[Valveman]

As long as there is no check valve at the tank, which there usually is, water will come back from the tank to the hydrant until the pump starts, then water will come from the pump. As with any hydrant(s), no matter where they/it are/is, is that you have to always use enough water to keep the pump from cycling itself to death. If you use large enough pipe to feed the hydrants, a frost free hydrant can let out 20 GPM or so, which is enough to keep the pump from cycling. But if the pipe to the hydrant is too small, it won't matter how open the hydrant is, it will be limited by friction loss from the small line.

If you are only burying 18"-24" you can use an irrigation valve box with the green lid. May need an extension or two for 24" deep, but they will work fine for ball valves to the hydrant lines. You could also install a Cycle Stop Valve model CSV1A in a valve box prior to the tee to the hydrants, which would let you use the hydrants anyway you want without cycling the pump on and off.

 

[Sponsor]

 

[Finch85]

As long as there is no check valve at the tank, which there usually is, water will come back from the tank to the hydrant until the pump starts, then water will come from the pump. As with any hydrant(s), no matter where they/it are/is, is that you have to always use enough water to keep the pump from cycling itself to death. If you use large enough pipe to feed the hydrants, a frost free hydrant can let out 20 GPM or so, which is enough to keep the pump from cycling. But if the pipe to the hydrant is too small, it won't matter how open the hydrant is, it will be limited by friction loss from the small line.

If you are only burying 18"-24" you can use an irrigation valve box with the green lid. May need an extension or two for 24" deep, but they will work fine for ball valves to the hydrant lines. You could also install a v in a valve box prior to the tee to the hydrants, which would let you use the hydrants anyway you want without cycling the pump on and off.

View attachment 100327

Thank you for the reply. So if there is a check valve at the pressure tank and a hydrant was installed - what is the potential risk? Cycling the well pump too much since it can not utilize the water from the pressure tank?

Do most people install shutoff's for yard hydrants? I'm thinking probably not but you'd obviously suggest that, correct?

 

[Valveman]

If there is a check valve at the tank, the pump will not come on when you open a hydrant.

I install a cut off to any lateral that tees off the main line.

 

[Finch85]

I believe I have a check valve at my pressure tank. I guess my original plan of installing a yard hydrant between the well and my house is a no-go.

BTW: MY pressure gauge reads about 10psi lower than it really is.

 

[Valveman]

Yep. That brass thing that looks like a coupling to the left is a check valve. Remove it or just gut and put it back as a coupling and you will be able to use the hydrant before the tank.

 

[Finch85]

Yep. That brass thing that looks like a coupling to the left is a check valve. Remove it or just gut and put it back as a coupling and you will be able to use the hydrant before the tank.

What is the need for the redundancy since the well pump I assume also has an internal check valve? Just in case if fails or you think the plumber did this because that's the way they always did it.

 

[Reach4]

What is the need for the redundancy since the well pump I assume also has an internal check valve? Just in case if fails or you think the plumber did this because that's the way they always did it.

That has been frequently discussed. Some states require it. Some states forbid it (because a leak in the underground portion can suck in contaminated water).

There have not been posts speaking of advantages for a while. The chief advantage is that if the bottom one fails, you stop cycling when not using water. There are a lot of disadvantages, and to me the only advantage would be to work around a failure until you next pull the pump to make the repair.

 

[Valveman]

Check valves fail from the pump cycling on and off too much. So, some people add and extra check valve or two, thinking if one is good more is better. I spend a large part of everyday advising people to remove the extra check valves for reasons like the hydrants, but mostly because they cause water hammer on pump start. Many so called experts don't understand how bad multiple check valves are for the system. Texas law says there must be a check valve above ground. But they also say you can't have anything in a system that will cause a negative pressure on an underground line, which is exactly what the extra check valve does. The engineers for the state of Texas are the ones who couldn't get a real job. So, not the sharpest tacks in the box. Lol! We just install the extra check valves until the house has been inspected, then quickly remove the extra check valve so there is no water hammer and the underground water line won't draw in contamination.

Cycling and slamming are the causes of check valve failures, which both of those things go away when using a Cycle Stop Valve.