Well Drilled - Results

[Pettrix]

can some one explain this perforated pipe? i would think it would cause issues with air getting in and stuff, i can see it at the bottom below the pump but i don't understand why it would be above it at all

It's a specially design PVC pipe for wells that has perforations in it to allow for water to enter the pipe and fill the well with water.
This 20 foot long pipe is staggered for the length of the well so basically water is filling the well from 220 feet to 500 feet. There's probably 450 gallons of stored water in the well when full.

 

[LittleBill21]

It's a specially design PVC pipe for wells that has perforations in it to allow for water to enter the pipe and fill the well with water.
This 20 foot long pipe is staggered for the length of the well so basically water is filling the well from 220 feet to 500 feet. There's probably 450 gallons of stored water in the well when full.

ok thats what i pictured but what happens if the water level drops below the 220 foot section? wouldn't he be sucking air into the system or am i missing something? also why wouldn't the water be pushing out of the perforations back out into the ground when the well turns on??

wait is this the "casing" pipe that is the outer pipe and there is another pipe inside that actually is hooked to the well?

 

[Pettrix]

ok thats what i pictured but what happens if the water level drops below the 220 foot section? wouldn't he be sucking air into the system or am i missing something? also why wouldn't the water be pushing out of the perforations back out into the ground when the well turns on??

wait is this the "casing" pipe that is the outer pipe and there is another pipe inside that actually is hooked to the well?

Air would not be trapped since oxygen is lighter than water and it would just purge itself at the top of the well. Think of carbonated soda.

Well pump creates a suction effect so water is drawn towards it.

 

[Pettrix]

Would a 3HP or 5HP pump be better with my well depth?

My two options:
3HP Goulds 3 phase pump OR a 5HP Gould 3 phase pump.

The pump installer wants to use a #10 wire for the 480 feet depth but can install a #8 wire but will upcharge another $400 for the thicker wire.

The pump installer also said that he wants to use 1.25" SCH 40 galvanized pipe for the last 380 feet due to the weight, depth and power of the pump. The first 100 feet from the pump level will be SCH 120 PVC pipe to prevent electrolysis.

My concern is will galvanized pipe rust?

 

[TheGoose]

What are your water needs? The pump you need cannot be determined without knowing how much water you need. House? Irrigation? Both?

 

[Pettrix]

What are your water needs? The pump you need cannot be determined without knowing how much water you need. House? Irrigation? Both?

For now it will be a 2 bed/2bath but a few years from now it will need to supply TWO homes with that one well.

Doing some irrigation (a few trees, plants, and maybe a small pond 15x20)

 

[Pettrix]

My concern is if the Schedule 120 PVC pipe can carry the weight of a 5HP pump (17 lbs) and the distance of 480 feet?

Maybe installing a 5 foot section of stainless steel pipe at the pump end to help absorb the torque of the motor and then running Schedule 120 PVC the rest of the way up.

 

[TheGoose]

I'm a licensed water well installer here in tx. I would go with the 3 HP and skip the VFD. I would also go with the largest tank you can.

 

[teejk]

One deep well I think! Can't remember the "target" around here but 12gpm sticks in my head...I'm sure we don't get that on a relatively new house but hard to tell. It might deliver that to the pressure tank but from there it gets "throttled down" with the size of the plumbing fittings. As far as I know the goal is to keep your pump running as few times as possible...every start puts strain on the pump and everything up. Volume is dictated by size of the pipe/tubing connected to the pump which sits inside the casing with plenty of room to spare (dunno if they still use them but years ago the tubes had what they called footballs...minimized the twisting motion of the pump when it started). You have a few pros opining here so I'll shut up.

 

[teejk]

I'm a licensed water well installer here in tx. I would go with the 3 HP and skip the VFD. I would also go with the largest tank you can.

Interesting...most residential installs use a very small pressure tank (bladder type). Would think that a larger tank would lessen the pump cycles. Is it strictly a function of keeping fresh water in the system?

 

[Egon]

Teejk, torque arrestors.

 

[Rustyiron]

I'd listen to The Goose.
What is your "static" water level?
At 20 gpm recovery, I would think the pump would not need to be so deep.

 

[TheGoose]

Using a large tank reduces the cycling. You can also use a cycle reducing valve like the CSV with a smaller tank.

Interesting...most residential installs use a very small pressure tank (bladder type). Would think that a larger tank would lessen the pump cycles. Is it strictly a function of keeping fresh water in the system?

 

[Pettrix]

So the 3HP pump is the better choice than the 5HP pump?

What I am concerned is that the 3HP pump will be "overworked" since it's 480 feet deep and I am at 5,000 feet elevation (a pump loses 1 foot of pump suction lift for every 1,000 feet in elevation).

 

[Egon]

Your downhole pump is submerged. Positive suction head.

 

[TheGoose]

The pump only sees the head from the water level. If the pump is at 400 ft but the water level is at 200 ft the pump will pump as if it is at 200 ft. As the well draws down the head will increase. If the well makes 20 gpm but the pump puts out 18 gpm the well will not draw down much.

Since the pump is submerged there is no suction loss.

So the 3HP pump is the better choice than the 5HP pump?

What I am concerned is that the 3HP pump will be "overworked" since it's 480 feet deep and I am at 5,000 feet elevation (a pump loses 1 foot of pump suction lift for every 1,000 feet in elevation).

 

[teejk]

Teejk, torque arrestors.

Yup! I knew the official name but adopted the local well-driller term (they look like a football that met a bandsaw). Had one fail once and the pump was allowed to spin...the torque ended up dropping the oil cap off the pump and dumped the oil into the well...not much but it took a long time to flush it. Our dog was our tester...we couldn't detect it after a while but he wouldn't touch his water until the oil was cleared.

 

[Pettrix]

The pump only sees the head from the water level. If the pump is at 400 ft but the water level is at 200 ft the pump will pump as if it is at 200 ft. As the well draws down the head will increase. If the well makes 20 gpm but the pump puts out 18 gpm the well will not draw down much.

Since the pump is submerged there is no suction loss.

Interesting, I didn't know that. So if the pump is a 480 feet which is 260 feet below the water level (220 feet static), the pump will act like it's in 260 feet of water.

So the water acts like pressure booster?

 

[Valveman]

Yup! I knew the official name but adopted the local well-driller term (they look like a football that met a bandsaw). Had one fail once and the pump was allowed to spin...the torque ended up dropping the oil cap off the pump and dumped the oil into the well...not much but it took a long time to flush it. Our dog was our tester...we couldn't detect it after a while but he wouldn't touch his water until the oil was cleared.

That would have been a very unusual circumstance. End caps on submersible motors do not come off because of torquing, they usually blow off from an electrical short. Torquing from the pump cycling usually just unscrews the pump and lets the whole thing fall down the well. Having said that, I hate torque arrestors. They have a tendency of swelling up, getting hard, and sticking the pump in the well. If you eliminate all the cycling, you won't have any torquing, and you won't need any torque arrestors. I wonder how you would eliminate pump cycling?

 

[TheGoose]

Water doesn't weigh anything in water, if that makes sense. Plus, for every foot of water there is about .4 psi. So at 260 ft of submergence the pump will have about 100 psi on it.

Interesting, I didn't know that. So if the pump is a 480 feet which is 260 feet below the water level (220 feet static), the pump will act like it's in 260 feet of water.

So the water acts like pressure booster?