New outside spigot won’t shut off, high water pressure

[Daniel N]

Hi, first post and it’s kind of a weird one... I recently added a new outdoor spigot in my back yard. I live on a pond I ran about 150’ tap down to my dock area. Used 3/4” PVC, same as the main line coming into the house from the meter. I dug up my existing line next to my foundation and installed a tee. Then I put a access box down with a gate valve at the new tee so I could isolate the new line in the winter. It’s buried about 18” all the way down to the dock.

So now my issue. I have extremely high water pressure. Checks about 130 psi. I assume there is a regulator under the house because my inside plumbing has normal pressure around 40 psi. Just never located the regulator.

Anyway, the new line down by the dock has a spigot valve for connecting a water hose. When I turn on the gate valve back up near the house the new spigot just spews and will not shut off no matter how tight you tighten it. I tried 3 brand new spigots and they all do the same thing. With the hose connected and a spray nozzle you can nearly pressure wash with the thing. The only way I can stop it is to shut off the gate valve up at the house.

Anyone ever seen a new spigot that is overcome by high water pressure? I suppose the proper solution would be to install the regulator out by the meter so all of my supply is the same pressure. But I’m afraid if I do that my already regulated indoor pressure will drop. Ideas?

 

[hj]

Almost ANY "spigot" will shut off with 150 psi pressure, (or even greater), so you have some other issue but we cannot tell you what it is.

 

[Sponsor]

 

[Terry]

You will need a pressure reducing valve for that. PRV

 

[cnotthoff]

You mention that you've run the line 150' down to the dock. Is that 150' of vertical drop or a horizontal run? I'm gonna assume that the pond is downhill from you house. I'm just not sure what your elevation drop is. Water pressure will increase a little less than 1/2 psi for each foot of drop. A gate or ball valve would have no problem shutting that off. If you end up installing a pressure regulator, install it at the dock.

 

[Daniel N]

The elevation drop is probably about 4 or 5 feet from the elevation of the gate valve. I would have thought a spigot could have handled that amount of pressure. It just sputters and hums instead of shutting all the way off.

Also, I would have thought the best place for the pressure regulator would be at the house side of the meter. That way the entire system is at a manageable pressure?

 

[Reach4]

What is this valve that fails like this?

 

[cnotthoff]

The elevation drop is probably about 4 or 5 feet from the elevation of the gate valve. I would have thought a spigot could have handled that amount of pressure. It just sputters and hums instead of shutting all the way off.

Also, I would have thought the best place for the pressure regulator would be at the house side of the meter. That way the entire system is at a manageable pressure?

4 to 5 feet won't add more than a couple psi of head. So, as Miss Emily Litella used to say "Never Mind" . No need to put the pressure regulator at the bottom of this run.

 

[Reach4]

4 to 5 feet won't add more than a couple psi of head. So, as Miss Emily Litella used to say "Never Mind" . No need to put the pressure regulator at the bottom of this run.

Pressure regulator at the bottom would let you run smaller pipe and still have the full regulated pressure at the dock. In other words, pressure drop on the way to the regulator would not count.

However that pressure-washer-like water stream could be nice for cleaning stuff.

 

[WorthFlorida]

You did not mention the type of spigot or hose bib used but I would keep away from the PVC type including PVC ball valves. If you used a fully turn spigot with a washer seat, with that pressure and water flow the washer seat may have been torn up a bit.

A foot or two before the spigot install a ball valve. You can close it off to reduce the water flow when the water is running and I like 1/4 turn spigots but that is a personal choice.

As other suggested do install a PRV and I would place it between the ball valve and the spigot so you can turn off the water if you ever need to service the PRV or spigot. Just a note that if you partially close the ball valve to reduce pressure and water flow, when no water is running, the pressure is not reduced and will read the same whether the ball valve is fully opened or partially closed.

 

[Jadnashua]

Dynamic pressure and static pressure are two different things. Dynamic pressure takes into account flow volume, pipe length, pipe diameter, and fittings used - those all create friction. Static pressure will be the same regardless of those factors. Basically, the more friction there is, the greater the dynamic pressure drop will be versus the static pressure.

 

[Daniel N]

Thank you all for the suggestions. I’ll see what I can do. The spigot I used is just a plain old brass hose barb from Home Depot that has a 3/4” male pipe thread. The second one I tried seemed to work the first couple times I tired it. A few days later, after being off a while and having pressure on it, it failed to shut off after using it to water grass.

I understand the gain in pressure from a drop in elevation and difference between static and dynamic pressure. I’m an engineer but I tend to over analyze things and over think stuff. Definitely not a professional plumber. That’s why this one had me stumped.

I figured the first failed spigot May have had to do with dirt in the pipe before the first use. Thought it may have messed up the seal. After 3 I wasn’t so sure. At any rate I’ll try some of the things suggested here and see where I end up. Much appreciated!