I have a crazy idea to pump water

[Doc_Bob]

This sounds simple but I've googled and searched everywhere but can't find any reference of anyone already tried this. Strange.... I wonder why?

Because you are a genius . Get out of that suit and do it! I want pictures!
Bob

 

[RonMar]

Why are you using the pump? Am I missing something here, Stumpfield where are you going to put the pump in the system? Centrifigal pumps don't pump air very well and like a shop vacume will certainly not pull enough vacume to lift water very far unless they are full of water. They will only move water and build pressure when they are full of water that CAN'T be compressed or stretched like air. Same reason why hydraulic systems don't work real well when full of air. If you are placing the pump at the top near the well head, you will have to haul enough water to fill the suction side hose and pump completely to make that pump move water and more importantly lift water that far(I have done this particular task a lot onboard ships). That is why that black cap is above the pump body, to prime and get all the air out of the pump(reference operators manual on robin subaru website). Since you will have to prime the system anyway, why not just prime the siphon pipe and let gravity start the flow.

The best Idea I have heard here so far for using this pump was from Alan B. Put the pump at the downhill outlet of the siphon and pump water backward from a tank near the outlet up to the well. Once the line is full and putting water into the well, shutdown the pump. The weight of the water on the outlet will reverse the flow and the siphon will be running. No valves or fittings involved and you can remove the pump at will without breaking the siphon as it will be on the pressurized outlet side of the siphon.

 

[MossRoad]

In your drawing you show the pump at the top of the hill.... why? If anything happens, like you close or open the wrong valve, you will lose the siphon and have to start over. Move the pump down the hill to the storage tank. Once you lift the water to the top of the hill it is no more work to lift it "DOWN" the hill to the storage tank.... I still think you are making it too complicated with all those valves and such. With the pump at the storage tank, if you remove the pump from the hose, there is no chance of losing the siphon accidentally.

 

[MikeD74T]

This sounds simple but I've googled and searched everywhere but can't find any reference of anyone already tried this. Strange.... I wonder why?

Maybe it's because you don't actually read or believe the answers to your question. The Greeks/Romans did this with rock pipes over 2K years ago. siphon siphons sifon sifons roman aqueducts aquaduct Computers won't move water, but hoses will. MikeD74T

And something a little more recent...Siphon Principle

 

[hilld]

I have a different question, how do you prevent freezing in a gravity system. With a pressurized system, you lower the freeze point of the water by a few degrees for every PSI, and at that altitude you are going to have some pretty cold days and nights. Just want to make sure you consider all possibilities before you venture into this too much.

Derek

 

[MikeD74T]

In northern NH where winter temps go below-45 F people keep their water from freezing by letting it run. Many use a hose on an outside faucet with a small washer as a flow orifice and let it spray up into the air in a location downhill from the house. They build ice mountains 20'+ high. Some add food coloring for a rainbow ice effect. Running water does not freeze which is why rivers still flow in winter. MikeD74T

 

[EddieWalker]

Running water does not freeze which is why rivers still flow in winter. MikeD74T

Not true, it just has to get allot colder for it to happen. Many of the bigger rivers in Northern Canada and Alaska become highways when they freeze. The truckers drive 80,000 plus loads over them all winter long. Same thing with waterfalls. When it gets cold enough, they freeze and some people even find it fun to climb them. Of course, a few die every year in the process.

Eddie

 

[SPYDERLK]

Quote: As to pipe sizes 'to restrict the flow' as others keep mentioning. Why? A simple valve on a 1/4" or 6" diameter pipe would do the same thing. Engineering with a valve is a lot simpler than trying to determine what pipe size will do the job.


The problem with sucking on water is that you slowly inexorably form a bubble that floats at the high point of the system. As long as there is flow in the system there is a fresh source of water containing dissolved gases. The inherent vacuum in a siphon draws these gases out - - the source of the bubble. As the bubble grows it increasingly blocks flow past it. The bubble is pushed downstream, but this is downhill toward the output of the siphon. Since the bubble is in the descending water column it lightens that column and lessens the ability of that column to pull water over the top. So, if the flow velocity of the water is too low the bubble will not flush thru, but continue to grow until it is large enuf to resist all the surplus head in the system and then flow will stop. With a six inch pipe several gallons of bubble would form while the 2GPM allowed by the throttle valve continued past it. As it continued to grow it would reach a level of blockage where even 2GPM wouldnt sneak by on he fringes of the bubble. You may notice this and open the throttle valve thereby restoring flow. But this is only temporary because the bubble continues to grow. It will finally stop the flow because in cannot be flushed out with a low flow velocity. With a 1/2" pipe at 2GPM there is good flow velocity. In a constant flowing system bubbles would be driven out as soon as they began to obstruct even a small percentage of the pipe cross section. The bubbles would be expelled before you even could notice their effect. Not only is larger pipe more expensive, it will turn into a maintenance problem in this flow capacity system. Use a pipe size that self limits to the flow rate you want considering the surplus head pressure you have - - Im guessing that is in the neighborhood of 8 feet of water. It will be trouble free if run constantly. If you were to turn it off - stop flow - for a week of so you may have to reprime.
Larry

 

[turnkey4099]

turnkey4099:

This is exactly what I'm looking for. Thank you! I hope I understood your sugguestion....

I will need to prime or do whatever neccessary to get the pump started to fill the hose full of water to start the siphon process. I would open the bypass valve and shut the pump down and let the siphon process take over. A check valve at the bottom of the pickup hose to prevent water draining back into the well and hopefully keep the pump primed in case I lose siphon and have to do this again (another valve to fill with more water if neccessary). A flow control valve on the discharge side to regulate the flow and keep it under the well's recovery rate to prevent any significant water level drop.

Of course, if I excavate down to reduce the lift, it may be easier to start the siphon and may be more reliable. But at only 2gpm and if I don't lose siphon very often, I may not need to do that.

Thanks again. Here's a sketch:

Yeah, that is the idea. Others say the siphon will work "through" the pump. Yes it will, but adds more restrictions that may tip the physics against you.
The bypass in your diagram also adds the bennie that you can pull the pump and use it elsewhere once the siphon has started.

A word on priming a pump. You probably already know this but... You have to fill both the pump and the suction pipe full with no bubbles. I used to irrigate out of the creek in front of my place. I spent far more time priming that cussed thing than I did on any other maintenance.

Harry K

 

[turnkey4099]

Why are you using the pump? Am I missing something here, Stumpfield where are you going to put the pump in the system? Centrifigal pumps don't pump air very well and like a shop vacume will certainly not pull enough vacume to lift water very far unless they are full of water. They will only move water and build pressure when they are full of water that CAN'T be compressed or stretched like air. Same reason why hydraulic systems don't work real well when full of air. If you are placing the pump at the top near the well head, you will have to haul enough water to fill the suction side hose and pump completely to make that pump move water and more importantly lift water that far(I have done this particular task a lot onboard ships). That is why that black cap is above the pump body, to prime and get all the air out of the pump(reference operators manual on robin subaru website). Since you will have to prime the system anyway, why not just prime the siphon pipe and let gravity start the flow.

The best Idea I have heard here so far for using this pump was from Alan B. Put the pump at the downhill outlet of the siphon and pump water backward from a tank near the outlet up to the well. Once the line is full and putting water into the well, shutdown the pump. The weight of the water on the outlet will reverse the flow and the siphon will be running. No valves or fittings involved and you can remove the pump at will without breaking the siphon as it will be on the pressurized outlet side of the siphon.

Yes that is where I would put the pump but...

Hmmm...at first I thought it would need a plug or valve at the high point to let the air out of the systme. True if a footvalve is used. Without a footvalve, it should work. Nice shade-treeing!

Harry K