Pipe type for a 330 ft well pump set

[ltkam]

Hello all. Looking for advice on my new well. The well itself is 358ft deep. Static water is at 260ft. 25gpm with the stem at 340ft for 2 hrs. 4 inch PVC casing. I plan to set the pump at about 330ft. The well is for a single family home with 1 full bath and a 1/2 bath. A few trees and about a 200 sqft grass area.

I would like to run a Grundfos 15SQE15-290 (can't find a 330) with a CU301 controller and transducer.

My main area of concern is the well pipe. First thought is to run 1 1/4" 200psi black poly. I could manage the installation with just a little help. If that will work, great. If not, threaded PVC seems like the next choice but I would probably need an installer at that point I think.
Any advice would be great.

 

[Bannerman]

Anticipating you are planning for a 40/60 psi pressure setting, to ensure the pressure switch will reliably shut off the pump at 60 psi even while the water level is lowest at 330' below grade, the pump chosen should be capable of building to 65 psi or greater.

As 1 psi is equal to 2.3', 65 psi will equal 149.5' + the actual 330' = a pump capable of 479.5' or more of vertical head should be chosen.

When the water level in the well is lowest at 330' below grade, the pressure directly exiting the pump to shut off the pressure switch at 60 psi will be 209 psi.

Instead of utilizing a CU301 controller and transducer to obtain constant pressure, recommend utilizing a more reliable and usually less expensive Cycle Stop Valve PK1A CSV kit shown here: CSV PK1A kit

CSV Interactive Animation

 

[Sponsor]

 

[Valveman]

As Bannerman said the 290 maybe a little light if the pumping level pulls down to 330'. But since the well tested at 25 GPM there may not be much draw down at all. From a depth of even 300' that pump will be fine. Also, as was said a CSV as in a PK1A complete pump control kit will be less expensive, last longer, and deliver strong constant pressure without all the complications and expense of varying the pump speed with the CU301 controller.

VFD Repair Kit – Cycle Stop Valves, Inc

Upgrade any variable frequency pump system to a reliable constant pressure system.

cyclestopvalves.com

 

[ltkam]

Thanks for the advice gentlemen. I am however more concerned with what piping to use in the well. I can install 200lbs black poly by myself (with a friend) but will it be enough? Going to schedule 120 threaded PVC will require an installer I think thus raising the price tremendously. I do not want a pipe failure so do I bite the bullet or chance the Poly?

 

[K_B]

I had the same questions when I put mine in at 280ft. I used a Grundfos 10SQ15-330 (2-wire). I used 1” poly pipe 200psi. Great flow and pressure. 6 months later, lightning took it out. I pulled it up and put in a Red Lion (3-wire with a control box). MUCH heavier pump, no soft start, etc., but cheaper. I had to run a separate ground wire down the pipe since I didn’t want to replace the 2-wire that was only 6 months old.
Be aware that if you use a CSV, depending on your pump, the back pressure may stress you out even more.
My back pressure is 190psi while filling the tank. Add another 122psi for the 280ft depth and I’m seeing 312psi at the pump outlet. 200psi rating for the poly makes a tense scenario for the layman (me). Others have said the pipe burst is really 2-5 times the rating, so that reduces the worry (some). In any case, mine with CSV seems to be doing fine (only had it a week, time will tell).

 

[ltkam]

Thanks K_B. I appreciate the advice without trying to sell me on a product.