Plumbing help, adding yard hydrants, pressure issue.

[GCncsuHD]

The wife decided she needed a massive garden this year. So far rain has been good and I've only needed to water it 3 times, but we are no strangers to drought conditions here so I'd like to get water to the garden, and this is a great time to add a hydrant at the garage parking pad for washing cars etc as well.

The garden is about 200ft from the well. I've got 200ft of 3/4" hose on a reel that I've used so far to get water to the garden. Right now I've just used a sprinkler and a garden hose nozzle to water the garden the few times I've needed it, but this summer I intend to build a drip irrigation system. The garden is pretty large, about 40x70, and there is no significant rise/drop in elevation from the top of the well pump casing to the garden.

The issue is that after a few minutes of watering the pressure goes way down, from the point that I am able to spray from one side of the garden to the other then all the sudden I can only spray maybe 10ft, same with the sprinkler, it goes from a 20' or so jet to not having enough pressure to oscillate. The hose is 3/4", as is the hose bib I am using off the top of the well, but the 3' whip from the hose bib to the swivel on the cart and the swivel itself are 5/8" and restrictive somewhat, though since the pressure is adequate for several minutes I don't think this is the issue.

The well/pump is off by itself in the yard. The expansion tank (50 or 60gal, I'll have to check) and the pressure switch (set to 40/60psi) is located in the crawlspace under the hose, approximately 100ft from the well, about 7' below the elevation of the outlet at the top of the well casing. I think it's 1-1/4" pipe from the well to the expansion tank. I have been attaching the 200ft garden hose to the 3/4" hose bib on the outlet at the top of the well casing.

The well is 8gpm, 350ish ft deep. I have not experienced any issues in the house, including even say filling the wife's 70 gallon garden tub and filling the washing machine at the same time. I only experience it at the garden.

Are my pressures screwy because I'm going directly off the pump and not going after the expansion tank/pressure switch?

Also I want to add a yard hydrant at the garden so I don't have to run hose, and another at the garage for washing cars. Should I use 3/4" or 1" supply lines for these? Should I connect where I have been, or should I connect under the house and after the expansion tank? Would I be better off if I relocate the expansion tank and pressure switch from under the house up to the location of the well and build a well house? Would there be any benefit to adding a second pressure tank at the well just for the garden irrigation, while the main pressure tank and pressure switch is under the house?

Here is a quick diagram of what I am working with, sorry if this is not the right section, I didn't see a plumbing section, I know it isn't directly garage related, but the water will be used at the garage some also... Forgive me, I am no plumber, just trying to figure things out, thanks for any suggestions.

WATER by wrfalcon75, on Flickr

 

[GCncsuHD]

Also, this may all be less of an issue once I get the drip irrigation installed since I would be flowing water at a much slower rate-i.e. watering on a timer over several hours vs spraying it down with a hose and nozzle over 20 minutes.


I just wish I would have had the extra cash to keep drilling when we did the well... a neighbor, well is about 500yds from mine, has over 100gpm and his well is about 125ft or so deeper than mine at 350ft and 8gpm. The other house on my property, my great grandparent's house, now a rental, is only 2.5 gpm, and bout 100ft shallower than my well.

 

[american-pacemaker]

It is most likely that your plumbed directly off the pump. The pressure tank
is your source of constant pressure in the system. As the pump cycles on and off the bladder in the pressure tank is what gives it the uniform pressure and not the pump.

 

[GCncsuHD]

It is most likely that your plumbed directly off the pump. The pressure tank
is your source of constant pressure in the system. As the pump cycles on and off the bladder in the pressure tank is what gives it the uniform pressure and not the pump.

I am plumbed directly off the pump, but unless there is some sort of check valve (is/should there be?) where I am connect logically shouldn't make a difference, other than a bit of head loss as the tank just tees into the water line. Logic would dictate that no matter which side of the tee water flows from the tank should help to balance the pressure

 

[csp]

Agreed. I have a hydrant right next to my well and my pressure tank is in the basement 100ft away. I don't have any cycles in pressure at that hydrant.

Pressure is pressure no matter where it is in the system.

 

[Flatland Dave]

There might be a back check aka anti-siphon somewhere before your pressure tank. Would explain a lot of this. How old is the system?

 

[GCncsuHD]

There might be a back check aka anti-siphon somewhere before your pressure tank. Would explain a lot of this. How old is the system?

Less than a year.

I was curious about a check valve in the system, it would seem that it could explain what I am seeing, but I have not seen one anywhere in the system. I would think there would be one to help keep the pump from losing prime, but where would that normally be located? On the pump itself? Somewhere below the pump head? It's a submersible.

This is my first time owning a home so I'm learning everything as I go.

 

[GCncsuHD]

Did a little reading here:
http://inspectapedia.com/water/Check_Valves_Water.htm
So I have an idea of what to look for. If my check valve is above the ground somewhere I know that may be the root of my issue and would explain it, though if it is below the ground then it should be unrelated.

This gives me a couple tests I can perform,
1. Connect to the hose bib in front of the house, see if I lose pressure after a few minutes the same way. I had not tried it there yet because A. I have to cross the driveway with the hose from there, and B. both hose bibs only have 1/2" supply feeding them.
2. Run the garden sprinkler directly off the pump head while going inside and having the wife fill the bathtub, see if by the tub filling inside, which should empty the pressure tank, thereby calling for the pump to come on, thus making each balance the pressure while it is running.

 

[jkwilson]

Run the hose and then go inside and watch the pressure gauge on your tank. If you don't have a pressure gauge, add one. If you don't hear the pressure switch click when you see the pressure drop significantly, it may need adjusting.

You are drawing water out through the largest pipe in the system by connecting near the well. In the tub inside, flow is restricted by the house plumbing.

 

[GCncsuHD]

Run the hose and then go inside and watch the pressure gauge on your tank. If you don't have a pressure gauge, add one. If you don't hear the pressure switch click when you see the pressure drop significantly, it may need adjusting.

You are drawing water out through the largest pipe in the system by connecting near the well. In the tub inside, flow is restricted by the house plumbing.

I do have a gauge, and I do plan on looking at that as well. I did go peek at the gauge several weeks ago while I was watering the garden with the sprinkler, watched the water start getting weaker at the garden so I went and looked at the gauge, water pressure was 40 something, but I was in a hurry and didn't stick around to watch it. Remember the garden is 300ft from that tank/gauge/switch so it takes a bit to walk over there.

As far as drawing out of the largest pipe, not exactly, I was drawing through a 3/4" hose bib, through a 5/8" hose swivel, then through 200ft of 3/4" hose. The tub in the house was drawing from the 1-1/4" supply line, which was restricted down to the same 3/4". The tub is only about 10ft from the outlet of the water tank in piping length. The garden hose is much more restricted than that is.

It's starting to sound more and more like I'm on the wrong side of a check valve wherever it is located.

 

[Charles (in GA)]

Pump is running, fills well tank, all the while the sprinkler is working fine. Pressure switch at the pump is satisfied, pump shuts off. Now the water in the garden is flowing all the way from the house/tank, back to the well, then to the garden. Lots more distance and the flow trickles. You don't say if it ever improves when the well pump kicks back on.

Problem is caused by the distance from the well to the tank and pressure switch. If there are no check valves between the well and the house (possibly one immediately at the well head) I would plumb in another well tank, a large one, 50 to 100 gal, right next to the well.

Easy to prove. Allow the well to pump up the tank and shut off. Trip off the well circuit breaker, run water at the garden but not at the house. If there is a check valve between the garden hose and the house, your flow at the garden hose will drop to a trickle verry quickly.

There may be a check valve at the tank and house inlet. Personally, I would remove it and install one at the well head. Then the whole system would respond to the pressure switch the same.

Charles

 

[Pluribus]

I have a similar setup to what you're proposing, except I have a hydrant located close to my well. The submersible pump is in the well, and the pressure switch and pressure tank is downhill at the house. IIRC, my pressure switch is set to turn on the pump at 40psi and turns it off at 60psi. Say I have an 80psi'ish pump, then every time it kicks on, the pressure is much higher at my hydrant. I'm guessing that while the tank is filling, somehow the pressure switch doesn't get to the 60psi cutoff, but I'm still getting higher pressure at the hydrant...someone else might be able to explain why that is.

When the pump is off, I can observe the change in pressure as the pressure tank depletes. Even when the hydrant is pre-pressure tank, it's still the pressure tank that is pressurizing your hydrant/hose; it just does it back up your main line to the well/garden area. If your pressure switch is set at anything lower than the psi your pump produces, then you will always have variable psi. If you have a check valve between the well and the pressure tank, then your hose pressure would be just about zero, not the variable flow you're now getting. In addition, turning on the hydrant/hose, wouldn't send any signal of a pressure drop to the switch, and your well pump would never turn on.

If you're going to use a drip irrigation system, I can't imagine the variable pressure being a problem. Unless it bothers you for the other times you'll be using water in that area, I'd just leave things as they are. If your hydrant/hose bib doesn't have some form of back flow prevention, definitely use something like this: http://www.globalindustrial.com/p/p...gclid=CJDTgKCk9b4CFUhufgodyKsAeg&gclsrc=aw.ds
It will keep water in the hose from flowing back into your water system.

*All of the above is based on people referring to check valves meaning back flow preventing valves, not pressure regulators. Oh, and I'm not a plumber either, just a homeowner hacker who has tried to figure out most of the same stuff.