My first question here. I like this site and the people who answer, thanks in advance.
Some background:
1) This is for a project in the rural Philippines. As a practical matter there are no codes, safety requirements (potable water) nor the like. It's for farm animals but also washing water for people.
2) I do have some construction experience, I can wire a motor to pump water, including laying a circuit with breaker and ground, lay pipe and the like (I'm not a construction worker however). I even helped drill a well, but this is the first project where we (I help a local guy about as skilled as I) will put all of these skills together. It should be simple and I have some ideas but there is a difference of opinion on the water delivery system design, hence this post.
3) Assume for this question I have the right size pumps, though feel free to opine on what type pump power is needed.
4) I do understand the theory of hydraulics, total dynamic head, pressure and flow rate (maybe not as good as you reading this, but better than average), but I'm just a layman so please use simple words. Keep in mind you cannot order just anything here in the Philippines (though I can have something mailed from the USA, but it may be intercepted by customs and that's a hassle). You must work with what is available, and they 'may not' (will not!) sell a constant-pressure inverter-drive submersible pump here as they would in the USA/Europe. The pumps I've found here are: (1) a regular impeller 0.5 to 1.0 hp pump that cannot run dry (needs a pressurized water inlet and pumps it through to the output) (2) a small submersible pump of about 0.25 hp), (3) a sump pump as in 2 that is larger, 0.75 hp, and needs to be primed with water to start, and/or be covered in water to operate, (4) a sump pump as in 3 that also has a ball type float valve switch fixed to the outside of it, so that the pump turns on when the float drops to a certain level (intended of course to keep the sump pump constantly covered in water)
Now for the project. It is to pump water from 10 feet / 3 meters (or less) underground, from the site of an existing hand water pump, to a house/barn about 25 meters = 80 feet away, with no elevation at ground level.
There are two water scheme proposals for this project, Project Proposal 1, my proposal, and Project Proposal 2, the local guy's proposal who claims he's done it before (I think he's fibbing, just to get the work, which he will get anyway even if he's lying since he's the only skilled mechanic in town lol)
Proposal 1:
I embed the graphic. My design.
Proposal 2:
His design.
Proposal I: Just in case you cannot read this graphic, it's very simple and I will describe it in words. I wish to pump water from less than 10 ft / 3 meters underground in a wet area where water sometimes shoots from the earth in artesian fashion, so the water table is just a few inches below the surface, and in fact a hand pump is already on the site and it's easy to pump water from the ground, though the hand pump must be primed with water to work, which I think is standard procedure for the hand pump in question. This is point A. From this point A, water will be pumped (how is one question, see below) to a air-over-water (i.e., open at the top) stainless steel tank, labeled B. From this tank, another pump, label C, will pump water for about 25 meters ~ 80 feet to a barn, label D. The barn D, pump C and tank B are all at ground level with little or no elevation. I use the pump C just to speed up the flow from pump C to the barn D.
Proposal II: the local mechanics proposed solution, which is to eliminate any first pump (whether above ground or below ground in the well bore hole), and simply put a bladder/ accumulator at the inlet of a ordinary water pump C that the manual says should never be run dry. The inlet of the bladder goes to the well (how it will be filled is a mystery to me, see below) and the outlet goes to the water pump C, which feeds the barn. It's very simple but I doubt it will work, see below.
Questions (all these questions amount to asking whether Proposal I or II is correct, or maybe they are both correct):
1) Compare proposal I with II, do I even need a pump A? To pump water from less than 10'/3m underground to above ground? The local guy (who's a construction worker) and I have a difference of opinion on this. He seems to think that due to the water table, all we have to do is stick a hose down the existing hand pump casting, and the pump "B", without even needing a air-over-water tank, and only needing a small bladder/accumulator to help even out the water flow, will suck water out of the ground. But this pump B is a simple pump of 0.75 to 1.0 hp that clearly states the pump should not run dry for more than a brief period or it will burn up and/or trip the internal circuit breaker. So I feel he is wrong.
2) Assume that I'm right in #1) above, and Proposal I is correct, what kind of pump do we need for pump A? A submersible pump of the kind they use in deep wells (30m typical)? That is cylindrical in shape and designed to operate inside a bore hole? I hope I'm wrong, as this kind of pump will be hard to find in this rural part of the world.
3) Assume that I'm wrong in #1), and Proposal II is correct, can we use any sort of pump A that sits above ground (where we can service it easily), and then stick a rubber tube from the inlet, down into the existing hand pump casing, and to the water table less than 10 ft / 3 m below ground? Or is this a special pump? As I say, the pump at the local "hardware store" (not a supersized hardware store, but very limited in inventory) is not intended to run dry. So how to keep the pump inlet constantly filled with water? Will any pump suck water that is less than 10 feet below ground, assuming it is powerful enough? (0.75 to 1.0 hp)? Perhaps with a bladder / accumulator that you can manually fill the bladder with water, to 'prime' this pump so that the pump inlet always has water feeding it, then stick a hose attached to the other end of the bladder/accumulator (which they do sell here) into the hand pump casing? That way the pump will always have some water in the inlet when it starts, and it will 'suck' the water into the accumulator as the pump operates. Again, the water table is very close to the surface, though this particular field is not extremely wet.
Best Answer
This is a very common setup, and basically the situation in my house. What you need is called a shallow well jet pump, and I believe this is what you are seeing in the store. Your suspicion is correct - that local mechanic is wrong. Some notes: