Currently I have a 1 1/4" stab well at 20' (close to water). The well is indoors and I plan on sinking another outside and building a well house. Too much condensation inside and it'll be nice losing the noise. Right now I intend on going to 2". Does anybody see a problem with a 3/4 horse pump pulling a 2" pipe at 25'? I have water at about 15'. If this would be too much work for the pump, I guess I could run a 11/4" pipe with check valve inside the 2" in case the pump doesn't want to pull that much without heating up.

 

I'm thinking you're pretty close to pushing the little pump to far. Most of the shallow well stuff is limited to about 26ft, but with a 2" pipe I think you're making it harder on the pump than it needs to be. The way I think of it is it has to lift all 2" x 25ft of water which is about 3.8 gallons of water just in the pipe, so it has to lift all 34lbs of water before anything comes out. Now if you stay with a 1.25" you're talking 1.5 gallons of water which is less than half the weight.

I tried hooking up a 1.5hp pump that was setting around to a well that had water at 25ft, but with a 40ft pipe and it collapsed the hose quite nicely!

 

I would think ideally, once the pipe is full and primed, the pump would just draw off it when without having to reprime every time. But, being an imperfect world, I imagine gravity would eventually win over the prime a lot easier in a 2" pipe, if it sat for more than a day. I guess for now, I'll just drive the 2" and put in a 11/4" pvc pipe with foot valve. The check valve for a 2" is $50 anyway.

 

Well it should hold it's prime, but what I mean is inorder for water to come out of the top it has to lift it from the bottom? (duh ) But getting to the point it has to lift the water all the way up, so whatever is in the pipe it has to lift. So if the pipe holds 3.8 gallons rather than 1.5 gallons, imagine the extra power the pump would need. Pumps love to push, not pull.

 

he is right don, you dont relly need 2" pipe anyways, if you have low water pressure now, it will just be worse with the bigger pipe, i know it sounds funny, but its alot of head PSI to overcome. put a good check valve in, preferable a spring type, and make sure everything is nice and clean.

 

buy a bigger pump or do a dual stage pump system.
your sub pump fills the tank above the well, then another pump takes over and boosts your water pressure to what ever you need (5000 psi with the right setup)

 

That sounds a bit expensive / complicated. I ended up going with a nice stainless steel 1 hp deep well pump on the setup I mentioned before. The name slips my mind at the moment but it is one of the biggest names out there and I got it for under $200 shipped, it is the quietest well I've ever heard.

 

My current well yields 5 gpm. Useable, pressure is ok, but I grew up in the city and like to see better pressure. I had been watching E-bay for a 1 or 1.5 horse pump. We got the 2" pipe driven, but stopped at 20' plus the point, after mangling the cap. The pit was pushing 8ft from the grade. We had water at just a couple ft below the bottom of the pit. This is all clean, white sand, not swamp. So comparitively, the point is down close to 30'ft below grade, compared to 19' on the old well. The pump will still only have the 23' of draw. At 25', a 1/2 horse pump gets about 4gpm, a 3/4h about 5 gpm (single pipe). Even though I am short of the 25' mark, I decide to set it up as a deep well. I ran into a guy in town that is at 24' with 2" set up for a deep pump. He gets around 12gpm with a 1 horse pump. Should be able to get 8-10 with the 3/4 horse. What will be nice is we got the trench for the supply line down 5' to the cabin. I do have to punch through about 10, of ground to get ander a tree I wanted to save. I'll probably get a steel pipe and thread the hose to the end and make a water jet. It's all sand unless there is a boulder in the way.

Talking to dug here at work, we decied tp pour a slab around the well. Put up a block wall around it. The house will easily be 6x6. Then Build a concrete slab for the top. It'll make a nice workbench/ fish and game cleaning station with a sink or spiggot. I'll get some cedar posts and make a canopy over it. I have lots of old tin roofing I took off the cabin.

 

A simple centrifugal pump when primed and not cavitating can almost develop enough vacuum to lift water up to the absolute limit of ~34' of water column. Add flow restrictions due to elbows, fittings, air bubbles entrained in the water, foot valve, too small a diameter well pipe and this effective number begins to quickly drop to much less than 28'.
Going to LARGER dia pipe will not cause more vacuum or "suction head" for the pump to try to overcome. This is because the same static suction head will be required to lift a given height column of water to the surface whether it is 1/2" pipe or 6" pipe. But when you start trying to FLOW a volume of water through a too skinny well pipe, the added restriction plus the static head gang up to greatly decrease the amount the pump can flow..

But, a primed centrifugal pump draws the least horsepower from the motor when the pump discharge is "deadheaded" than when it is thrown wide open, pumping max flow volume.
If a simple centrifugal water pump is drawing too much current regardless what size well pipe you already have, try throttling the pump discharge a little to reduce the amount of motor amps.

K.