Fitter30
Well-Known Member
Floats control the pump. Pressure switch is used for a high pressure/dead head safely switch if motorized valves don't open and pump turns on.
Well/Pump/Cistern Electro-Hydraulic System Input
- Thread starter Gustave
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There is a yard hydrant, so the pressure switch is needed for more than a safety. If the yard hydrant were connected upstream of a check valve feeding the upper tank, then then the pressure switch may not be needed.
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Gustave
Member
Actually, as you mention, the cistern fill-ports are at the very top of the tanks, above the water level. So it is not possible for the tank contents to drain back to the well. Only the water in the fill pipe could drain back. According to my math (for a 2" line) that could be about 115 gallons, which is not insignificant.
I am not sure if the ball valves are spring loaded. I suspect not. They do have manual overrides in case of power failure.
It is very possible that both tanks will "call" for water at the same time, so that both ball valves open. If the net result is that the lower tank fills first, then the upper tank, that is ok with me (the lower tank is mine). These tanks are quite big, to satisfy CalFire. For domestic water use only the top 1/4 - 1/3 of the tank is consumed before refilling, leaving plenty of reserve for the upper tank, while it waits for the lower tank to fill back up.
The reason for including the CSV was only to prevent pump cycling when using water local to the well (with both ball valves closed).
I did not find a pressure switch with a factory 65-85 psi calibration. I did find a Pumptrol with 60-80 psi calibration and hope that it can be adjusted a little higher.
I hope that the pressure accumulator tank will be ok at these higher pressures. The diaphragm should only see the differential pressure across its surface, so that should be fine. And I assume that tank is good to well above 85 psi.
Thank you - Gustave
Gustave
Member
Thanks for the tip - Gustave
Gustave
Member
That is one concern I've had. Having the pump turn on with both ball valves closed. I'm pretty sure that is not good for the pump.
Gustave
Member
That would sort of work, giving about 115 gallons of supply with constantly reducing pressure. Since as you reminded me, the fill ports are above the water level.
A 120? psi pressure relief could be useful. Standard cheap water heater temperature and pressure relief valves are 150 psi.
Will your pump be set 400 to 600 ft down?
Bannerman
Well-Known Member
Even as your intention for using a CSV is to eliminate pump cycling only while the yard hydrant is utilized, a CSV regulates the flow rate directly from the well pump so all water including cistern refill will flow through the CSV.
Because the system pressure will need to be raised, as previously suggested, the pump can then be fully controlled by the pressure switch, thereby eliminating the need to run wiring from the float switches to the pump controller. Alternately, the flow into each cistern could be controlled by a mechanical float valve within each cistern, thereby eliminating the necessity of motorized ball valves and power at each cistern, although power will continue to be needed if you wish to incorporate water level alarms.
Because the system pressure will need to be raised, as previously suggested, the pump can then be fully controlled by the pressure switch, thereby eliminating the need to run wiring from the float switches to the pump controller. Alternately, the flow into each cistern could be controlled by a mechanical float valve within each cistern, thereby eliminating the necessity of motorized ball valves and power at each cistern, although power will continue to be needed if you wish to incorporate water level alarms.
Gustave
Member
550 feet actually. Would the pressure relief valve be used as a blow-off in case the pump dead heads against two closed ball valves? To help save the pump?
Yes. I don't know what the ideal pressure would be. While it is not common, I would consider a 200 to 300 psi pressure gauge before the CSV.
Is that a 10 gpm pump or a 7 gpm pump? Is that schedule 120 PVC pipe down to the pump?
Consider a flow inducer sleeve for the pump to enhance cooling, and some other possible advantages.
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Gustave
Member
Yes. I hope that the CSV can be adjusted to work at these higher pressures. I am not yet that familiar with how it works.
I now see that using the pressure switch to control the pump is the best method. However, I still would need to run wiring from the float switch in the tank down to the motorized ball valve by the well.
Now this is interesting. The type of mechanical float valve you mention was brought up in an earlier post (perhaps by you?). Comes from Australia. I read up on it. Sort of like a toilet fill valve. No power needed. Too bad I already purchased the ball valves. Also, my neighbor's system is already up and running. And he has the wires leading to and from the float switch. So there is not too much to be gained on his end.
I could do a hybrid system, with a ball valve for the neighbor and a mechanical float valve for my side. Then I could run the wiring up to the tank strictly to bring electrical power up there.
Gustave
Member
The well was drilled and the pump installed in 2015, as part of the sub-division of our properties. It's 2 HP and produces 10 GPM at the well head. But I do not know much more about it.
Bannerman
Well-Known Member
Linked below is the specifications page for the adjustable CSV model. It specifies the adjustment range to be 15-150 psi.
Various videos which explain how a CSV functions are included on that site.
Valveman is a moderator on this forum and also the designer and manufacturer of CSV devices.
https://cyclestopvalves.com/pages/csv1a-specifications
Bannerman
Well-Known Member
Ball valves remain useful to isolate each cistern from the pump during cistern maintenance such as allowing the water level to drop in each cistern prior to cleaning.
Because the ball valves utilized in this fashion will normally remain fully open, there will be little purpose or benefit in motorizing them.
You haven't explained how water is delivered from each cistern to each home. Is the difference in elevation between each cistern due to hilly property, or is each cistern elevated above ground so water flow to each home is reliant on gravity?
Gustave
Member
The flow from the tanks to the respective homes is via separate lines, and is downhill, but in different directions than the fill lines. My neighbor's house is about 10 ft lower than his tank. Ours is about 80 ft lower.
Yes, the terrain is hilly.
If that is to the bottom of the tank, that is getting to where you could consider gravity alone. Avoid the maintenance of a pressure pump.
Gustave
Member
Yes that is to the bottom of the tank. The tank is 16 ft tall I think. We've run some garden hose down from the tank to the house pad and the pressure is pretty decent. Sprays out of the house real nice and will power an oscillating sprinkler just fine. I calculate 35-40 psi or so. We put the tank up on the hill mainly for fire protection. To allow CalFire to use the hydrant without a pump.
If you look at a pressure loss calculator, you can see what size pipe gives you low pressure drops at household use pressures. A house seldom used more than 10 gpm.
http://www.pressure-drop.com/Online-Calculator/
SIDR pipe is often good bang for the buck. Avoid steel pipe for household water. For PVC, you want to take into account thermal effects. https://www.charlottepipe.com/Documents/PL_Tech_Man/ExpansionandContraction.pdf For SIDR, you snake the path of the pipe, but you can't do that with PVC.
http://www.pressure-drop.com/Online-Calculator/
SIDR pipe is often good bang for the buck. Avoid steel pipe for household water. For PVC, you want to take into account thermal effects. https://www.charlottepipe.com/Documents/PL_Tech_Man/ExpansionandContraction.pdf For SIDR, you snake the path of the pipe, but you can't do that with PVC.
Bannerman
Well-Known Member
Beautiful view!
My purpose in asking about the cisterns being elevated and gravity flow was in consideration to the extent the well system pressure could be potentially reduced by relocating the upper cistern to the same elevation as that home.
If there ever should be a fire, I anticipate the fire dept will be unlikely to use a yard hydrant but will be more likely to use a 3-4" suction line to draw water from the cistern using a high volume pump to supply multiple 2.5" or larger lines. For rural properties where there are no fire hydrants, they will typically bring additional water in a tank truck.
My purpose in asking about the cisterns being elevated and gravity flow was in consideration to the extent the well system pressure could be potentially reduced by relocating the upper cistern to the same elevation as that home.
If there ever should be a fire, I anticipate the fire dept will be unlikely to use a yard hydrant but will be more likely to use a 3-4" suction line to draw water from the cistern using a high volume pump to supply multiple 2.5" or larger lines. For rural properties where there are no fire hydrants, they will typically bring additional water in a tank truck.
Gustave
Member
Thanks.
Everyone 'round these parts uses 2" Schedule 40 PVC for all lines from well to tank and tank to house. Seems to work ok, I've not heard of issues. There is suddenly some type of PVC shortage around here. But I managed to secure what I need.
Gustave
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