Quick Submersible question

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Rngr275

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From my other post it was recommended that I use a submersible pump. I have a cistern that is ~24" deep. What kind of submersible can I use? Can a "standard" well submersible be used on its side?:confused: or are there short submersibles or are we talk the kind of submersible that I see used in sumps/utility pumps? This pump will feed the houses water supply.

Thanks
McD
 

LLigetfa

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You just have to make a sleeve for it so it draws from the bottom. You can use a length of PVC and a well seal at the top.
 

Valveman

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You need the sleeve or shroud to keep the motor cool in a large body of water. But you can lay it on the bottom and it will work with less than 6” of water.
 

LLigetfa

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The point I was trying to make is that the pump creates a vortex (whirlpool) and will suck air before the level reaches the intake. The shroud acts as a barrier to reduce this vortex.
 

Valveman

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The point I was trying to make is that the pump creates a vortex (whirlpool) and will suck air before the level reaches the intake. The shroud acts as a barrier to reduce this vortex.

A good trick to eliminate the whirlpool is to place a flat sheet of steel, plastic, or anything about a foot in diameter just above the intake.
 

Valveman

Cary Austin
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Laying a pump on its side won’t fry the bearings. I have done it for years and years. You just don’t want to run a pump at wide-open flow (no pressure) while it is on its side. Of course you don’t want to run a pump at wide-open flow (no pressure) when mounted vertically either. It is a lack of backpressure that causes up-thrust and destroys pumps, not the fact that they are laid on their side. Manufacturers will recommend installing submersibles at a 45 degree angle. This is thought to let gravity hold the impellers down and not up-thrust. However, as I said, even mounted vertically they will up-thrust if you don’t have some backpressure on them.
 

TJanak

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Valveman,

How much back pressure is needed? 10 lbs?

It's relatively common here to run a 4" submersible wide open with no restriction to fill small reservoirs, stock tanks, etc.
 

Valveman

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It depends on the pump. Look at the far right side of the pump curve. For instance with a 10 GPM, 1/2 HP that would be about 80' or 34 PSI minimum. You can also tell by the flow rate. That 10 GPM pump will upthrust over about 14 or 16 GPM.
 

Texas Wellman

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I could have wrote the below post.

I've seen em run for years and years open ended. Always wondered about restricting the pump....but never seen it done.

Last thing somebody wants to do is pay big bucks to see a large stream of water and then throttle it back.


Valveman,

How much back pressure is needed? 10 lbs?

It's relatively common here to run a 4" submersible wide open with no restriction to fill small reservoirs, stock tanks, etc.
 

Valveman

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There is probably enough restriction in the pipe and fittings for a little ½ HP. The more impellers a pump has, the worse the up-thrust will be. Adding 30 PSI of backpressure will not restrict the pump. A 10 GPM pump will max out at about 16 GPM anyway. It will still pump 16 GPM with 30 PSI restriction, the impellers just won’t be grinding against the top.
 
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