Well pump recommendation with high static water

[Brody Reb]

6" casing well drilled to 515 ft with static water level of 10ft. 15 gpm blown yield. Previously posted about this for a deep pump set but well flow rate has changed plans after frac.

I'm thinking of setting the pump at 300' with a CSV1A kit set at 60psi with 50/70 switch. A single CSV1A should work without high pressure concerns right?

2 story home, 8.5 potential bathrooms (6.5 finished), inground irrigation system for grass approximately 3/4 acre, potential pool in future.

Well driller and pump installer use Franklin pumps. The high static water level confuses me for pump selection. Routine water use makes me think a 3/4hp 15gpm pump would be ideal, but I want it to at least work for instances when the well is drawn down to 300ft (running irrigation system or filling pool). Maximum head for this 3/4hp 15gpm pump is 250' and the 1hp 15gpm has a maximum head of 350' per specs in description.

https://www.rcworst.com/Franklin-El...e-Pump-15-GPM-0-75-HP-230V-3-Wire-p12077.html

https://www.rcworst.com/Franklin-El...le-Pump-15-GPM-1-0-HP-230V-3-Wire-p12027.html

My total head calculations are probably off, but this is what I did.
300' set depth + 60psi csv pressure (60*2.31=~140')= 440' of head (190 psi)
My total head calculation exceeds the Franklin 1hp 15gpm pump max head specs, but the chart shows it pumps up to almost 400ft. Is that just ideal range for max head or am I mixing things up here?

I will be getting a pump install quote from the installer but want to go into it with as much knowledge up front. What Franklin pump model and size do you recommend I ask for?

Thank you in advance

 

[Reach4]

1. When using these graphs, you must add about 162 to the needed head plus a bit of margin. This will let you shut off the pump with a 50/70 pressure switch. You will need more HP. Using the tables, rather than the graph, is easier generally. When asking if there is enough flow to do stuff, look at the flow for 40 psi. For turning off the pump due to pressure, gpm is not a significant factor. If the pump runs at 50 or 39 psi at the surface for hours, that's fine.

2. With the high potential difference between high water and low water, you want to keep this 15 gpm pump from pumping more than 21 gpm when the water is high. This may require a 20 gpm or so Dole valve. Those valves have maximum pressure drop specs. The pump turns on at 50 psi (115 ft of water). 115+10=135. So when the pump kicks on, there will be about 135 ft of head. There is a condition called upthrust you want to avoid. (corrected this item and graph, I think.)

3. The CSV also has maximum PSI drop specs.

4. If you can draw 5 gpm @50 psi, and 2 gpm @70 psi from 300 ft, that will handle most uses in the house for this unexpected condition. Screw the irrigation and pool filling at that point.

5. A 10 gpm pump is probably enough gpm for normal big house use, since you don't run everything at once.

6. To turn off the pressure switch, in the unlikely event that the water drops to 300 ft, I think it would take the 1.5 HP.... 162 ft pressure head + 300 ft. If the water is found to have dropped a lot, you could adjust the pressure switch downward.

 

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[Valveman]

The 1HP would probably work fine. But if the water level does pull down to 300' that pump will only make about 5 GPM at 20 PSI. The max you could do with the CSV1A is the 1.5HP. Setting the CSV1A at 60 PSI means you need a max inlet pressure of 185 PSI to stay within the 125 PSI differential we recommend for the CSV1A. With a static level of 10 ' and 460' of head possible from the 1.5HP pump, that would be 450' of head or 194 PSI. I would not be afraid of the CSV1A with 14 PSI extra on it. We have some fudge factor figured into the CSV1A. Upping the system pressure to 70 PSI and using a 60/80 switch would decrease the CSV1A differential pressure to 124 PSI, and would give you more pressure at the house.

 

[Brody Reb]

1. When using these graphs, you must add about 162 to the needed head plus a bit of margin. This will let you shut off the pump with a 50/70 pressure switch. You will need more HP. Using the tables, rather than the graph, is easier generally. When asking if there is enough flow to do stuff, look at the flow for 40 psi. For turning off the pump due to pressure, gpm is not a significant factor. If the pump runs at 50 or 39 psi at the surface for hours, that's fine.

2. With the high potential difference between high water and low water, you want to keep this 15 gpm pump from pumping more than 21 gpm when the water is high. This may require a 20 gpm or so Dole valve. Those valves have maximum pressure drop specs. The pump turns on at 50 psi (115 ft of water). 115+10=135. So when the pump kicks on, there will be about 135 ft of head. There is a condition called upthrust you want to avoid. (corrected this item and graph, I think.)

3. The CSV also has maximum PSI drop specs.

4. If you can draw 5 gpm @50 psi, and 2 gpm @70 psi from 300 ft, that will handle most uses in the house for this unexpected condition. Screw the irrigation and pool filling at that point.

5. A 10 gpm pump is probably enough gpm for normal big house use, since you don't run everything at once.

6. To turn off the pressure switch, in the unlikely event that the water drops to 300 ft, I think it would take the 1.5 HP.... 162 ft pressure head + 300 ft. If the water is found to have dropped a lot, you could adjust the pressure switch downward.

Thanks Reach, lot's of useful info and details to parse out. I will ask about the Dole valve.

The 1HP would probably work fine. But if the water level does pull down to 300' that pump will only make about 5 GPM at 20 PSI. The max you could do with the CSV1A is the 1.5HP. Setting the CSV1A at 60 PSI means you need a max inlet pressure of 185 PSI to stay within the 125 PSI differential we recommend for the CSV1A. With a static level of 10 ' and 460' of head possible from the 1.5HP pump, that would be 450' of head or 194 PSI. I would not be afraid of the CSV1A with 14 PSI extra on it. We have some fudge factor figured into the CSV1A. Upping the system pressure to 70 PSI and using a 60/80 switch would decrease the CSV1A differential pressure to 124 PSI, and would give you more pressure at the house.

Thanks Cary, I will discuss the 1hp/1.5hp pumps with the installer. Upping the system to 70 PSI seems worthwhile as well, I haven't come across that yet so I'm glad you brought that option up!

 

[Reach4]

Looking again, I am thinking you would not need the Dole valve with the 1.5 HP pump. The flow as you cross that worst-case lower red line looks to be less than 21 gpm.

 

[Brody Reb]

Looking again, I am thinking you would not need the Dole valve with the 1.5 HP pump. The flow as you cross that worst-case lower red line looks to be less than 21 gpm.

Great, thanks for pointing that out. I'm learning little by little.

 

[Valveman]

When the pump starts at 60 PSI, that is the same as having 138' of head on the pump, and it will not upthrust. But this only works when the only check valve in the system is on the pump at the bottom of the well the way it should be.

 

[Brody Reb]

I will make sure the only check valve installed is the one on the pump. Thank you

 

[Reach4]

I will make sure the only check valve installed is the one on the pump. Thank you

One more just above the pump is good redundancy.

 

[2stupid2fixit]

8 bathrooms? That is a hotel not a house
Couldn't afford a Franklin/Goulds at the time this happened, but...
I bought a Hallmark 3/4 horse MA0459X-14A for about $150 on ebay. People laughed at me. I've spent more money in one shot by taking BBW out to dinner at Cheesecake Factory. The thing hasn't broken yet, even though we are all daring it to break. If you can change out a pump easily by yourself in a short period of time, then one of these chinese time bombs is the way to go. Although raising pump on 300 feet of poly sounds like a day in hell. Mine is hung 200 feet down and water normally appears at around 48 feet.

 

[Brody Reb]

8 bathrooms? That is a hotel not a house
Couldn't afford a Franklin/Goulds at the time this happened, but...
I bought a Hallmark 3/4 horse MA0459X-14A for about $150 on ebay. People laughed at me. I've spent more money in one shot by taking BBW out to dinner at Cheesecake Factory. The thing hasn't broken yet, even though we are all daring it to break. If you can change out a pump easily by yourself in a short period of time, then one of these chinese time bombs is the way to go. Although raising pump on 300 feet of poly sounds like a day in hell. Mine is hung 200 feet down and water normally appears at around 48 feet.

That's great. I'm all for DIY when possible but yes, I think I would be asking for trouble when it comes to this. Are you using a poly drop pipe or pvc? I think I remember seeing people using truck winches to pull their pumps that were ~100-200 ft.

 

[Fitter30]

Drop pipe charts
https://www.slpipe.com/product/drop-pipe/

 

[Fitter30]

Suction curve for 15 gpm

 

[Brody Reb]

1. When using these graphs, you must add about 162 to the needed head plus a bit of margin. This will let you shut off the pump with a 50/70 pressure switch. You will need more HP. Using the tables, rather than the graph, is easier generally. When asking if there is enough flow to do stuff, look at the flow for 40 psi. For turning off the pump due to pressure, gpm is not a significant factor. If the pump runs at 50 or 39 psi at the surface for hours, that's fine.

2. With the high potential difference between high water and low water, you want to keep this 15 gpm pump from pumping more than 21 gpm when the water is high. This may require a 20 gpm or so Dole valve. Those valves have maximum pressure drop specs. The pump turns on at 50 psi (115 ft of water). 115+10=135. So when the pump kicks on, there will be about 135 ft of head. There is a condition called upthrust you want to avoid. (corrected this item and graph, I think.)

3. The CSV also has maximum PSI drop specs.

4. If you can draw 5 gpm @50 psi, and 2 gpm @70 psi from 300 ft, that will handle most uses in the house for this unexpected condition. Screw the irrigation and pool filling at that point.

5. A 10 gpm pump is probably enough gpm for normal big house use, since you don't run everything at once.

6. To turn off the pressure switch, in the unlikely event that the water drops to 300 ft, I think it would take the 1.5 HP.... 162 ft pressure head + 300 ft. If the water is found to have dropped a lot, you could adjust the pressure switch downward.

Had to come back to thank you Reach4. The charts were a starting point to glance at but your suggestion to use charts at 40psi is much more useful. This particular F&W pump also is right in line with what valveman suggested for a 1hp pump.

Looking at the 1 HP pump at around 300ft.
https://www.flintandwalling.com/con...rt-10-GPM-4-in-S-Series-Submersible-Pumps.jpg

 

[Valveman]

That 1HP can still make 70 PSI for the pressure switch shut off as long as the water level in the well stays above 285'.

 

[Brody Reb]

That 1HP can still make 70 PSI for the pressure switch shut off as long as the water level in the well stays above 285'.

So in the unlikely event that we ran the well down past 285', we would just experience reduced pressure? When we stop using water and the water level rises everything would run correctly? That sounds ideal.

 

[Valveman]

With such a high static level you should have plenty of water from that depth. You might want to install a Cycle Sensor to protect the pump in case the water level is pulled down lower than 285', you stop using water, and the pump cannot shut off until the water level rises.

 

[Brody Reb]

With such a high static level you should have plenty of water from that depth. You might want to install a Cycle Sensor to protect the pump in case the water level is pulled down lower than 285', you stop using water, and the pump cannot shut off until the water level rises.

Thanks, I plan to. Will reach out for support when that comes.

 

[Brody Reb]

Some progress. Pump was installed but things didn't go exactly according to plans, as usual.

Pump set at 300'. static is 10'. Plan to set pressure switch at 50/70 and potentially go up to 60/80 if everything works ok to reduce the differential to prolong CSV life.

Grundfos 15SQE15-290
https://www.waterpumpsdirect.com/Grundfos-Pumps-96160195-Water-Pump/p80388.html

I requested 250# poly but at time of install they only had 200# on truck. 2 hose SS clamps at both ends installed 180 degrees. The total head lift shows 485', which is lower than other 1.5hp pumps but I think that's a good thing since they only had 200# poly. 485'-10' static=475' or about 205 psi max back pressure the system will be under before the CSV right? I plan to install a gauge in upstream of CSV to monitor it as well, but am I asking for trouble here?

 

[Reach4]

Maybe a 20 gpm Dole valve?