Well pressure tank placement, size of water line

[Crashhed]

My well is installed at bottom of hill. Its 75' deep. Where I need to pump to is approximately 105' elevation from bottom of well to cabin. around 600' of waterline will need to be run. I need to know what size water line I need to run, wire size, and pressure tank size. also tank at bottom of hill or at top at cabin.

I'm getting 5-6 gpm

 

[Reach4]

I'm getting 5-6 gpm

What does that mean?

What diameter is the well, and how far down is the top of the water ("static water level")?

4 bedrooms and 4 bathrooms, heavy irrigation, big backwashing iron filter?

 

[Sponsor]

 

[Crashhed]

What does that mean?

What diameter is the well, and how far down is the top of the water ("static water level")?

4 bedrooms and 4 bathrooms, heavy irrigation, big backwashing iron filter?

2 bedroom 1 toilet 1 bathroom sink shower and kitchen sink
trying to figure out what size water line i need to run up the hill. my well is at bottom of hill. the elevation is 105ft total. and do i need to put pressure tank near well or up at cabin. the waterline would be 600ft long

 

[Crashhed]

2 bedroom 1 toilet 1 bathroom sink shower and kitchen sink
trying to figure out what size water line i need to run up the hill. my well is at bottom of hill. the elevation is 105ft total. and do i need to put pressure tank near well or up at cabin. the waterline would be 600ft long

6 in well static water level is 15 ft

 

[Reach4]

pipe length =65 down to pump+600+compensation... let's use 700.

For pump depth, lets say 65ft. The pump would be set between 55 and 65 typically.

So is the pressure tank at the well, or at the house? At the house will give better regulation, but you have to run power or control wire to the well. With power at the well, you could do the pressure switch and pressure tank at the well, but the pipe should probably be bigger to avoid pressure drop to allow the washing machine running to not cause sudden pressure change in the shower. So maybe use a 25 gpm for for pipe friction calculations . At 25 gpm, a 1.5 inch pipe would lose about 16 psi, and 2 inch would lose about 4 psi. Either of those would be acceptable, with the 2 inch being better.

So for having the pressure tank and switch at the house, I would think 10 gpm for pipe friction calculations would be sufficient. At 10 gpm, a 1.5 inch pipe would lose about 3 psi due to friction. A 1 inch pipe would lose about 21 psi, which would be file with the pressure tank and switch up top. 1.25 would lose about 7 psi. That would maybe be what I would use, tho 1 inch would not be a problem at all with the tank and switch up top.

A 7 gpm pump would be good. That might deliver 10 gpm under some conditions.

So how much head due to altitude? 65+105 =170 it should still work. At 25+105 =130 the pump will operate a lot. So let's plan to be good in that range. A 1/2 hp 7gpm pump would do the job, but as the level in the well fell, you might be limited in flow by the well production rate. A 3/4hp 7 gpm pump would give more pressure and flow as the well was about to be sucked dry. Most would choose that.

10 gpm pumps are cheaper for a given HP (has fewer stages). If you went that route, you would want 10 gpm 3/4 hp or 10 gpm 1 hp.

Either way I would go with a 44 gallon pressure tank, such as Well-X-Trol WX-250.

If you do go with a pump house at the well, consider putting in a sub panel. And to reiterate, house pressure will be steadier if the pressure tank and pressure switch are at the house.

An alternative to the bigger tank is to use a CSV with a smaller tank. With this you would want to make sure the pipe is rated higher before the CSV. That would be no problem, since the lightest polyethylene pipe you might consider would be rated for 160 psi, and none of the pumps can produce that.

 

[LLigetfa]

Locating the tank and CSV at the cabin should lessen pressure loss variation due to friction since the upstream pressure would be higher. I say "should" since usage patterns could be conceived that would negate such constant pressure.

Never count on the pressure tank compensating for friction loss as the tank's buffering is very short lived after which the tank refilling contributes to the friction loss. The tank's main role is to be a timer to reduce cycling.

 

[Valveman]

With the pressure tank at the top of the hill the pressure setting only needs to be 40/60. At 40/60 with a CSV you would only need the 4.5 gallon size tank. You would need at least a 44 gallon size tank if not using a CSV.

With the pressure tank at the bottom of a 105' hill you will need to add 45 PSI to make up for it. That would be a pressure switch setting of about 80/100. At 80/100 you would need twice as large a tank. With a CSV that would only be a 10 gallon size tank. Without a CSV I would use an 86 gallon size tank.

Either way the CSV and smaller tank would work much better than a large tank without a CSV.

A 3/4HP, in the 10 GPM series is really all you need. With that pump you would have 160 PSI back pressure on any of the pipe prior to the CSV. 160# or 200# in 1 1/4" pipe would work fine going up the hill.

 

[Crashhed]

Thanks to everyone for their help. This was very helpful. Hope to give this a try soon