What depth to place my pump

[Fishyone]

having recently drilled another well which is 460' PVC 5" casing and perforations at 435' to 460' and 195 'to 205 '. This is where the elog showed the strongest water to be.
I was going to put the pump at 225/250 until I read on this forum that the pump should be set above the perforations so the motor would cool correctly. My dilemma as one can see is the pump would be below one but above the other.
Living in an area that has miles of orchards and rice fields, the static water will fluctuate as much as 35' depending on time of year. Currently its at 62' during summer it was 95'. I want to give it some buffer so say worst case static with drawdown 120' . Would like to know if its better to set the pump above say at 190 or just set it at 225/250 . thereby not worrying about having to lower it in the near future

 

[Reach4]

I was going to put the pump at 225/250 until I read on this forum that the pump should be set above the perforations so the motor would cool correctly.

A flow inducer sleeve will cool the motor properly, even if the well is top-feeding. You can search for "flow inducer" using the search box above.

 

[Sponsor]

 

[VAWellDriller]

What's really important is not the static water level, but the stabilized pumping water level. Did the driller report the yield and/or do a pump test? What were their recommendations? A 4" pump with sleeve will be a tight fit in a 5" well; it may or may not go depending on casing thickness. You can easily fit a 3" Grundfos with 3" sleeve, but that will limit you to 1.5 HP and about 15 gpm.

 

[Reach4]

What's really important is not the static water level, but the stabilized pumping water level. Did the driller report the yield and/or do a pump test? What were their recommendations? A 4" pump with sleeve will be a tight fit in a 5" well; it may or may not go depending on casing thickness. You can easily fit a 3" Grundfos with 3" sleeve, but that will limit you to 1.5 HP and about 15 gpm.

I think you are concerned that the clamps will increase the effective outer diameter.

In https://terrylove.com/forums/index.php?threads/idea-for-flow-inducer-construction.86907/ I proposed a flow inducer where slots would be cut, and the worm gear clamps would shrink the diameter at that point.

But with worm gear clamps around the outside, the worm gear hump adds less than 1/2 inch to the effective OD, doesn't it? I don't find specs on hump size for clamps.
4 inch SDR 35 ( ASTM D3034 is 4.215 OD.

 

[VAWellDriller]

The sewer pipe would work, unless he has a slide pitless. It would be tight. Thickest 5" they make in well casing is sch80 and minimum ID is 4.7".

Sounds cheap, but I use good 2" 10 mil pump tape to secure sleeves....and have never had one come off. It's smooth, no snags. Have installed many on big pumps in rock wells with multiple fractures. I've also fished out sleeves that were put on with clamps.....clamps have snagged and broken during installation or removal and sleeve falls right off.

 

[Fishyone]

The flow inducer is what i will use. I do not have a slide pitless.(what ever that is for). another question related to depth to place the pump.
I've mentioned placing the pump at 190' above the perfs. or 250' below the perfs. I know that valveman and others like the pump above the perforations, and i am a believer in valveman's knowledge. But, placing the pump with a flow inducer at 250' should ensure never having to lower the pump again. What is the difference in back pressure behind a csv at the well head between 195' and 250' if there is not that much difference and i can still get my 17 to 19gpm, 250' would be better for me. If the difference is minimal why not set the pump at 425 above the bottom perforations? would that take a bigger pump? here's the parameters :
well depth 460' / static 120 / horizontal to tank and pressure switch 105' /tdh 246'/ pressure switch 30-50 /gpm at house 20 / pump is f and w 4f19s15301 19gpm 1 1/2 hp / down pipe 1 1/4 pvc sch 120.
Am i just over thinking this? I don't seem to be able to grasp the concept of why the pipe below the water line doesn't matter Or does it.
I've been advised by the staff at valveman's business that my back pressure using the csv at the well head would be 108 (pump set at 190) and that there would not be to much pressure with the above mentioned pump. What about 250' .

 

[VAWellDriller]

Without knowing the pumping water level, no one can answer your question. You well may draw down 2 ft at 20 gpm or it may draw down 200 ft at 20 gpm. You cannot properly size a pumping system, select a proper pump, select a proper pump installation depth, select a proper control valve....etc without some idea of well yield and specific capacity. What did the driller recommend? Did they characterize yield and drawdown? I suspect that you have good producer and that the water level would never even come close to the top of the upper screened zone, but I'm in VA and I don't know much about groundwater in California.

 

[Reach4]

What is the difference in back pressure behind a csv at the well head between 195' and 250' if there is not that much difference and i can still get my 17 to 19gpm, 250' would be better for me. If the difference is minimal why not set the pump at 425 above the bottom perforations? would that take a bigger pump? here's the parameters :
well depth 460' / static 120 / horizontal to tank and pressure switch 105' /tdh 246'/ pressure switch 30-50 /gpm at house 20 / pump is f and w 4f19s15301 19gpm 1 1/2 hp / down pipe 1 1/4 pvc sch 120.

The pump effectively lifts water from the surface of the water. Yes, there is a slight friction increase with a longer pipe, but it is not much.

As the water gets lower and lower, the flow from the pump will decrease. I would like to size the pump such that if the water level fell to a little above the pump, the pump might only be pumping 1 gpm. If the well can keep up, that would be enough to survive on. So I would not choose a pump that can drive 10 gpm from that depth.

One good reason to not put the pump at the bottom is to not suck sediment. However 20 ft above the bottom is usually enough for that. Otherwise it will be the expense of the pipe, the time to insert and pull sections, and a little more weight. I am not a pro.

Incidentally, if you run some open-end tubing to the area of the pump, you can measure how much water is standing above that open tubing. Blow with a compressor, and for every psi you can maintain, there is

 

[Fishyone]

The pump i plan on using is currently in a well within 20ft. of the new well. the current well is 135' deep and the pump is set at 130'. The water table is currently at 61'. however as stated the static will drop 30-40 ft. during the orchard and rice field pumping times. S0 last year the water got to 95' and i lowered the pump from 110' to 130'.(in the old well) this was precautionary as all around me wells were sucking air and burning up. As a further precautionary move we drilled a new deeper well, one that would last into the future.
The drawdown in the old well was 8 feet running the pump without shutoff for an hour. I don't expect the new well to drawdown any more then that, if that. The static i put into the problem at 120' is a worst case scenario including the drawdown. with all this long story/history i'm sure i'm just confusing everyone, but in my defense i'm already confused .
As my tdh is 246 by placing the csv at the well head i am trying to ensure that the back pressure created by the csv has no chance of bursting the drop pipe.

 

[Fishyone]

I'm sure i'm asking questions and explaining things that are just confusing to most who are trying to help. So what i will do is quit worrying and just go with what i was told.(by valveman) Some things i just don't need to understand al be it i love to learn of new things even at 75yrs

 

[Reach4]

https://www.wwpp.co/F_W_19GPM.pdf has pump curve and tables.

 

[VAWellDriller]

The pump you have selected is only capable of producing 375' of head (162 psi).....so if your piping can handle that nothing else matters.

Sorry if I got too technical in questions. The last post was the first time you mentioned anything about possible drawdown or a pumping well. You mentioned fluctuations in seasonal static conditions. Since the new and old wells are fed from different formations they likely have different characteristics.

 

[Fishyone]

thanks for the help. VAWelldriller, you need to pack up your rig and head west. Northern calif. is not the same as LA or San fran. I had been on a list to get a hole drilled since last april. 6 months and some drillers are out further then that. $65 a foot for residential. Ag wells who knows

 

[VAWellDriller]

thanks for the help. VAWelldriller, you need to pack up your rig and head west. Northern calif. is not the same as LA or San fran. I had been on a list to get a hole drilled since last april. 6 months and some drillers are out further then that. $65 a foot for residential. Ag wells who knows

Business at all time high here too. Theres not enough money to make me go to the land of fruit and nuts.

 

[Valveman]

Like VA says that pump can only build 162 PSI max. And that is at the bottom of the string. The reason we figured 109 PSI at the CSV is because of the pressure loss lifting from the 120' static water level to the surface. If you know the well doesn't draw down more than 30-40 feet, there is no reason to install the pump much deeper than that. If the water level draws down 80-90 feet more you would need a larger pump anyway.

 

[Reach4]

Suppose you set the pump at 300 ft. If the water is down to 225, you can leave the pressure switch at 40//60. If the water falls to 275, you reduce the pressure switch to 20/40 while you plan things.

Flint & Walling 19gpm 1.5 hp pump.

 

[Fishyone]

Business at all time high here too. Theres not enough money to make me go to the land of fruit and nuts.

Business at all time high here too. Theres not enough money to make me go to the land of fruit and nuts.

As stated northern calif. is not the same as LA or San Francisco area. Unfortunately these days every state has its fruits and nuts just depends on what part you live in. I was just giving you an invitation and giving your business a little promotion for the good advise you gave me on the forum. thanks

 

[Valveman]

Yeah don't worry VA all the fruits and nuts from California are moving to Austin.