Picture of ~ World's Greenest  WATER PUMP ~
Hydraulic Ram Pumps are very old technology that pump water using gravity and 2 valves to generate a repeating water hammer effect. The "hammer" pounds a little of the drive water into a pressure tank then up the delivery hose for your use. Why is it green? Because it's simple, reliable, pumps water without any engine, fuel or electricity or muscle power and can be made from mostly recycled materials.

The one I built has a few novelties that make it more reliable, cheaper and easier to operate than most of the plans you find on the Internet. It developed a steady 28psi pressure at the pump and delivered about 1,000 gallons per day where we wanted it.

last season, it hammered over 145,600 gallons of pond water up a steep hill to our garden over 700 feet away and over 100 feet higher than the pond! In the process, it saved us over 485 liters of diesel fuel we would have normally used to drive our diesel tractor to pump and tow the water around our farm.

The pump was built for about $50 worth of plumbing parts and a bunch of stuff that I had sitting in my scrap pile.

What's the secret? A strong gate valve - period.

Please have a look and enjoy the instructable and don't forget to rate it.

Please let me know if I can make it better or easier to follow somehow, and I will be happy to answer any questions that you have so post away!!

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Step 1: Get started!

Picture of Get started!

Parts list.

You may want to print this picture to refer to later as an assembly guide.

Step 2: Build a better gate valve!

Picture of Build a better gate valve!

All the available plans for ram pump valves are based on converting a conventional foot valve to operate in reverse. The trouble with this solution is you end up with a valve that is flimsy, wobbly and unreliable. It works, but it wears out too fast and jams up too much. My design takes care of it by starting from scratch and making it strong. My wife says I am strong like bull and smart like tree so I make everything I build that way. I also like to use whatever I have around the farm so that is exactly what I did. You could build it prettier and simpler, but recycling scrap is a priority around these parts, especially if you are broker than the ten commandments... This project really paid off for us, it just works great.

You need the picture of all the valve parts to see that it's easier to build than than it sounds below...so let's GO...

I had a 2" to 1.5" copper reducer with a short piece of 1.5" pipe attached and that makes the valve body. I also had a 6" brass tail stock sink connector that I inverted and soldered inside the reducer because that had a nice smooth lip that makes a perfect valve seal with no work at all. If you have a new reducer and smooth it off with sand paper, you likely don't need the tail stock step but you do need a smooth edge for the valve seal to contact or else you will not get it working. Now drill minimum 2 (or 4 is better) 3/4" holes through the pipe just above the reducer and smooth the edges and presto, your exhaust port is all done.

Next problem... how to replace the O ring seal used in converted foot valves. It routinely wears out or slips out of place and stops your pump. So, let's not fool around. Take a hockey puck and use a hole saw to make it 1.85 " in diameter so it fits inside the 2" reducer and has lots of clearance around the outside. Drill a 1/2" inch hole exactly in the center and put a bolt and nut on it so you can hold it in your drill press. Then spin it with a file against the edge so you get a nice smooth beveled edge about 1/4" long. This presses up against the smooth tail stock lip to form your valve seal so make it as smooth and even as possible and it will work better.

Now get some plastic washers that slide easily inside the tail stock piece. I had a piece of scrap plastic around so I turned it on my lathe to fit. It works as a centering guide for your valve to keep it closing and opening in a straight line. (This is one reason other converted valves often fail.) The fit needs to be loose but not too sloppy, say 1/16" clearance.

Now make a top cap. I turned a scrap piece of aluminum so that it fit into the tail stock and had about 1/2" of overhang left at the top just like a cupboard knob. The half inch center hole is threaded to fit the rod, but you could just use a clearance hole and a couple of retaining nuts on the top and bottom. You need to be able to adjust the height of this cap as this is the regulator that controls the pump cycle frequency and efficiency. A giant wing nut would work too, just something to hold the valve stem from falling out the bottom due to gravity when it cycles up and down.

Now assemble your valve. Put about 6 0z. of weight on the bottom of the threaded rod. (I drilled a 1/2" hole in a piece of scrap steel, you could use heavy washers, just smaller diameter than the hockey puck which sits nicely flat against it. Put the puck on the rod then a washer on top about 1/2" smaller than the puck bevel then lock it in place hard with a retaining nut. (This valve cycles 2.5 times per second and receives lots of force (remember that water hammer discussion earlier, well, the hammer part is for real!) so lock it down strongly. This is another reason foot valve conversions fail as there is no way to stop the valve assembly from wobbling all over the valve body and it wears the stem or guide too quickly and frequently pops the foot valve O ring off the groove. That can't happen with my brute of a valve.)

Now put another retaining nut on the rod about 2" above the puck assembly. The valve cycles up and down about 1/2" so you want your plastic center guide to sit above the exhaust ports when it's all assembled and resting in the down position. Now put a retaining nut on top of the plastic center guide and tighten it down.

Almost there. Slide the finished valve stem assembly into the reducer so the threaded rod sticks out the top. Now spin on your top cap adjuster until it slides into the top of the tail stock and permits the valve assembly to move up and down about 1/2". Put a wing nut on top of the cap to hold it in place. You will have to loosen or tighten this cap a few turns at a time to make your pump operate optimally.

Step 3: Button it up.

Picture of Button it up.

The hard part is over.

Now take the fire extinguisher and make a pressure tank out of it. You do that by screwing off the extinguisher handle and stuffing a recycled, deflated 20" bicycle tube inside the tank and then inflate it to about 5psi., that's it.

Next, assemble the pump like you see it in the parts list picture and lash it down to something strong or it will walk all over the woods. (remember that water hammer discussion earlier, well, the hammer part is for real!) so lock it down strongly, I used 4 x 3' fence bars bolted to a board and a 10" concrete block. I strapped the pump to that with copper plumbing straps and stainless screws. The feed water pipe is connected to the pump with a rubber plumbing connector.

Step 4: How it works...

Picture of How it works...
Ram Pump CYCLE 2.jpg
Ram Pump CYCLE 3.jpg
Ram Pump CYCLE 4.jpg

Here's how to operate it:

To run it, you need about 5' of feed water pipe for every 1' of fall below your pond or creek water surface. I have 10' of fall and 50' of feed pipe supplying 3 gallons/min. (A little longer would be better say 5.5:1)

Now manually push (cycle) the valve stem up and down about 30 or 40 times to fill the pressure tank. These pumps need back pressure in the tank to operate automatically. When the pump starts to cycle on it's own, you will want to screw the adjuster cap up or down to make the cycle frequency about 60 - 150 cycles per minute.

Experiment with the cycle frequency to find what delivers the most water for you. Lots of troubleshooting guides on the net to help you fine tune it. You may need to add or remove some weight off the bottom of the valve stem if it cycles too fast or slow and you don't have enough adjustment available by turning the upper valve cap. A little denial and error and you will find the sweet spot to get it running smoothly.

I have found that if it cycles too fast, it won't build up any pressure and the delivery flow is low or stops. If it cycles too slow, delivery flow is weaker and you use more feed water than necessary and you can drain the feed pipe if your supply water is limited. Mine seems to deliver the most water at a cycle rate of 150/minute.

Enjoy your gravity powered water pump, it's the closest thing you may ever see to perpetual motion... Hopefully you can see the movie of it working.

This is the best hobby project I have ever built from scrap parts and recycled junk. We use it every day all summer long and it facinates everyone who comes to visit us while saving real money!

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den23m4 days ago

how to install the bicycle inner tube inside the tank

eltigre (author)  den23m4 days ago

The tank is turned on/off via a pipe thread that originally sealed the fire extinguisher squeeze handle mechanism to the top of the tank. Before you screw the tank on to the pump, just deflate a bike inner tube all the way and you will have enough room to poke it into the tank with a finger or blunt end of a pen or a dowel or such, keeping the inflator valve for the last thing to go in. When the tube is all inside, just inflate to about 5lbs pressure and screw the tank on to the pipe.

A few years later I made an ABS tank out of a piece of 4" drain pipe and drilled a hole for the inflator valve so it was outside the tank and could be inflated once or twice a summer without shutting off the pump.

evyl007 days ago
I am ready 2 start buildg aquaponics w/grow beds & want 2 use this ram in design. I need 2 know if "waste" water has enough force 2b redirected upwards back n2 tank. Supply @ bottom of tank, waste outside tank going back 2 tank, delivery going 2 grow bed (3ft or more each 4 delivery & waste)
eltigre (author)  evyl006 days ago

If I understand you correctly, you can't blow the waste water back into the tank it came from as gravity won't let you but you can put it into a different tank slightly above the valve exhaust port as the water exits with some force. This pump design needs a continuous head of water to operate. If you drain the supply tank, the pump will stop.

evyl00 eltigre6 days ago
I actually just watched a YouTube of a guy from landhome.com who actually submerged his ram pump & it still worked! This is doable! Everyone is actually lifting water a great deal of height/length though so I may need help figuring how to reduce the amount of water flow b/c I will be going from inside the tank to about 3' or so straight up into a pvc piping ring above the grow bed.
evyl00 eltigre6 days ago
Well there is going to be a bell/siphon in the grow beds stationed above the 250 gal fish tank which will put the grow bed water back into the tank. I just need to devise a way to have the blow off or waste captured and returned instead of spilling on the ground. Using a capture bucket won't be feasible b/c I may not always be there to empty, hand pumps won't work because that kind of defeats the whole purpose. I will have to think on this. Thanks for the quick reply! If you have any other thoughts to share, any help would be greatly appreciated!

can we buy a set of instructions for this?

something like this?

eltigre (author)  cheesewhiz141 month ago

I don't have a detailed set of plans but the info above should be enough to get you there. try it and let me know if you have problems and I will talk you through your build.

ldscaper23 days ago
Have you tried to lift water from a well? Do you know how many feet it can lift? Ever consider selling one? I like the old school technology!
eltigre (author)  ldscaper23 days ago
This design needs a head( height difference) of water to create a water hammer needed for operation. Unless you can think of how to make water flow inside the standing column of well water this design can't operate there.

I did see an old patent that claimed it had a ram pump design that worked in a well but I never investigated it.
eltigre (author) 2 years ago
You could use high pressure pvc. My experiments with plastic did not go well because the constant pressure surges caused the abs fittings to burst after a few weeks. maybe if you are using a small diameter pipe like under 2" it will work for you. There are many designs on the web that show plastic pump bodies. I never had a problem with bursting after I built the pump body out of steel fittings.

You can definitely run the outflow back to the pond surface for agitation purposes. If the outflow is directed through a smaller diameter nozzle, it will spray quite far. I got at least 20 feet out of a 0.25" nozzle. You may get even farther out of a smaller diameter nozzle.

"You could use high pressure pvc.... the abs fittings ..."

Were you mixing ABS (fittings) with PVC (pipe)?

I thought they were incompatible.

eltigre (author)  charlessenf-gm2 months ago
No, I only used abs pipe which connected to a steel "T". I suggested that you might have better luck with high pressure pvc.
JordanR63 months ago


Do youknow if these kind of hydraulic ram pumps would be full submersible? I am wanting to build a pond with a waterfall and small stream that is self contained. My idea would be to place the intake at the far end of the pond leading to the ram pump at the other end of the pond. I am wanting it fully submerged so the water loss isn't an issue for maintaining the pond's water level.
Do you know if that would cause any sort of pressure issues?


TomP14 JordanR62 months ago

You can't put the water from the exhaust back into the same reservoir it came from. It has to flow down hill to create the energy to drive the pump.

Thank's for getting back to me so soon. I Like your site very much.I believe I may be able to salvage my old waste valve and create a new base out of material i have in my boneyard. The Pond has an old air box that was used to regulate water level. It has a 12 in pipe that drains at the base of the embankment equal to 10 ft of head. I have sealed the drain because the old stand pipe or box has rotten away at base. I have been pondering if it would be possible to create a waste valve that would connect to the 12 inch pipe that then would connect to a fabricated steel air box with a bladder a threaded delivery line at 6 inch. I will try to send a sketch. Again great site and thanks for any advice.

eltigre (author)  drew.stevenson.7146 months ago
I'm not sure how large your waste valve is, but if it's anything 4" or under, you may be faster and cheaper just to run a new feed line out of ABS drain pipe. I used 50' of 2" ABS as a feed line connected to the pump with a rubber coupling covered with a stainless clamp. like this:
and it worked fine for years. No fabricating & easy to take on & off. I imagine you could go up to 4" this way pretty cheaply but you might start to have trouble with the coupling leaking pressure at that diameter so you may need a threaded union joint for greater strength... like this:
Post a sketch or link to tinycad drawing so we can see what you are thinking.

eltigre (author) 6 months ago

Hi Drew,

I see no reason you can't scale up my impulse valve design to whatever size you need and bolt it to whatever ram pump body you prefer. I turned down a 2" hockey puck for my 1.5" valve size but you could buy bigger chunks of rubber or polymer than a puck. Something like a boat roller guide might serve you. e.g. http://www.easternmarine.com/3-1-2-x-1-2-yates-bo...

The best advice is to make sure the valve stem runs up and down smoothly and centered. Do that by attaching at least 2 centering guides made of plastic. You could cut them out of sheets of 1/2" or thicker polyethelyene or buy some nylon casters of the correct size to act as centering guides so the valve stem must stay aligned to the valve seat.

Post a sketch if you like & I will comment on it for you. you might like the free CAD program here: https://tinkercad.com

to help you design something.

Hello. I have used a ram pump from folk ram pumps. It was an aluminum cast body which over the years has broken. I was able to make a new bell housing out of eight inch well casing i had however the aluminum cast waste valve assembly has also gone the way of the body. I am now without a pump. The pond that i am using is 4 acre ft I have 8 ft of head and have a 3inch feed pipe in place with a flow rate of 200 gal a minute i would like to manufacture my own pump and would greatly appreciate any help or advice you could offer.

ahirdstudent7 months ago
Maybe I'm just clueless, I certainly don't have any experience or skills to suggest otherwise. But couldn't you use a certain amount of the generated flow to run a watermill generator, to provide constant power along with your water flow, and avoid any issues of lack of sunlight? As long as you have a constant supply of water to draw from, and if possible to retribute to the source, then couldnt you leave it running indefinitely?

You could provide your water for gardening, livestock, drinking, washing etc, generate power....

If you could make a viable hydrogen fuel cell, you could be completely green and off grid theoretically..

Or is it not a viable system?
eltigre (author) 1 year ago

Hi Boraan,

If you feed a 2" ram pump with a 4 meter vertical drop, you should have good luck driving it with a 20 L/m solar pump. Just hook the solar 1" outflow directly into the ram pump 2 " feed pipe. You can adjust the speed of the ram pump cycle to make sure you have enough drive water in the ram pump feed pipe. If it is adjusted to just barely spill over the top of the ram pump feed pipe, you will never have your ram pump stop due to lack of feed water.

Your trouble will be that the solar pump will stop feeding at night, then you will have to start the whole system again each morning. This design of ram pump is not self starting. To start it, you will require a long, light weight rod attached to the ram pump top valve so that you can push it down several times to prime the cycle. This will be annoying to you. You may be better off with a small self priming high lift gear pump attached to a simple water wheel driven by your solar pump outflow. Alternately, you can try to get a high lift low voltage pump that is directly driven by your solar cells and eliminate the double pump setup you are envisioning.

Or just get a low voltage compressor driven from your solar cells (or use an inverter to make high voltage) and run an airline down to a bubble pump. That way all your mechanism is above ground with no moving parts in the water or well. much easier to service everything. Ram pumps are easiest to operate and service when you can keep them at ground level and they have a continuous flow of feed water.

Or build a teeter totter with a piston pump on long rods over the well. Then the kids can play all day and pump water at the same time.

Boraan 1 year ago
Thank you for the suggestions,ElTigre. I plan to do as you say and hang the ram over the floating bilge pump. But do you think I should connect directly to the Ram or install a tank to feed the ram? The bilge output is inch. The waste water I want to run through an airlift pump allowing some of it to be pushed up by the air in the waste water.
Boraan 1 year ago
Thank you for the suggestions,ElTigre. I plan to do as you say and hang the ram over the floating bilge pump. But do you think I should connect directly to the Ram or install a tank to feed the ram? The bilge output is inch. The waste water I want to run through an airlift pump allowing some of it to be pushed up by the air in the waste water.
eltigre (author) 1 year ago

Hi Boraan, Actually I think you could use your low lift solar pump to feed a ram pump that would move water much higher. You could suspend the ram pump above the water line of the well and fill its feed pipe with the solar pump output. The ram pump exhaust would go right back into the well and the ram pump output could be delivered to a much higher level than the solar by itself. You could fill barrels at the top of the well overnight or run a gravity feed system of pipes from the well to where the water is needed. You might be able to run 2 ram pumps from that much feed water. worth a try. Another maybe easier idea is to use your solar pump to turn a small water wheel that directly drives a piston or gear pump that will pump water above the ground level. You can also use the solar cells to make compressed air which in turn runs a bubble pump. https://www.youtube.com/watch?v=95LVVe7OpRM or use a windmill pump

paul.bobby2 years ago
we are missionaries in Nicaragua. We want to install one of these water pumps on a small island. The island is surrounded by a huge lake.
The question that we have is; can install the pump underwater and use the water pressure to power the pump?
We need to go 100' up and 300' inland.
Has anyone done this? Do you have any plans for this? Can you help us?


eltigre (author)  paul.bobby2 years ago
If part of the island is lower than the surface of the lake you might be able to make it work. These pumps need a head of water to operate. If you do not have the height of water it won't pump. All it takes is a small stream flowing from the island to the lake and you could make it work. Otherwise, you are better off with a wind or solar powered pump. If there is a steady current in the lake you could also try a sling pump.
I know zilch about pumps. But as a volunteer in Cambodia, I have been trying to learn. Poor farmers need water in the dry season. Where we are there are no streams to work with. But I have installes solar driven 12V bilge pumps to deliver water up 5 Meters with a flow of 20 liters/minute. Can this be used to drive a ram pump ina 30 Meter dug well? If it can many people will benefit from the water. Any thoughts?
Place the pump in the bottom of the water, deepest accessible part. Get a ring float and tie the feeder pipe (with an inlet filter) just enough below the float to keep it submerged at all times. let the vertical pressure of the feeder pipe run the pump. Incidentally, you will probably need a relief/exhaust pipe as well. Use a larger diameter feeder pipe than the relief pipe so that the pump can generate pressure.

Also, FYI, I have seen these as closed loops, which do not emit water at the pump but capture both sides of the pressure to enhance the pump capabilities. I don't remember where I saw it but some googling should get you going in the right direction. Same premiss however, floating feeder pipe.
eltigre (author) 2 years ago
You could use high pressure pvc. My experiments with plastic did not go well because the constant pressure surges caused the abs fittings to burst after a few weeks. maybe if you are using a small diameter pipe like under 2" it will work for you. There are many designs on the web that show plastic pump bodies. I never had a problem with bursting after I built the pump body out of steel fittings.

You can definitely run the outflow back to the pond surface for agitation purposes. If the outflow is directed through a smaller diameter nozzle, it will spray quite far. I got at least 20 feet out of a 0.25" nozzle. You may get even farther out of a smaller diameter nozzle.
fr0ggy2 years ago
hello, i have a question about the feeding pipe.
the 2'' is a constant, or depends of the ... debit of water ?
like if i have a like slow river, is ok to use 2'' pipe ?
eltigre (author)  fr0ggy2 years ago
You can use whatever feeding pipe you like, as long as you have enough water flow to keep it full. I used a 2" pipe because my pump body was 2" so it was easy to connect them together. If you have too little feed water flow or too small a feeding pipe, the pump will cycle very slowly or not at all. The pump may also cycle very quickly but not build up any outflow pressure.
fr0ggy eltigre2 years ago
so, as long the river (water) level is above the feeding pipe (and i keep the 5:1 ratio), is ok ? pipe will always be full of water.
eltigre (author)  fr0ggy2 years ago
Yes, as long as you can keep a full feed pipe you should be fine. If any air gets into the feed pipe it may stop your pump. You may like a 5.5:1 length to height ratio better. My pump works ok with 5:1 but all the Info I have seen says 5.5:1 is optimum.
fr0ggy2 years ago
so, as long the river (water) level is above the feeding pipe (and i keep the 5:1 ratio), is ok ? pipe will always be full of water.
Diddi Ingi2 years ago
One question... with the pressure that the hammer builds up, how far upstream can you pump the water, using a regular garden hose? How far above the level of the original pond f.x.?
eltigre (author)  Diddi Ingi2 years ago
this pump has about 700 feet of 3/4 inch flexible plastic pvc water pipe attached to it and the delivery point is about 110 feet above the pump.

Garden hose is about the same diameter but more flexible so it may not deliver as much as the flexible walls will absorb some pressure. the shorter the delivery hose, the more water you will have at the end of the hose. The larger the diameter of the delivery hose, the less it will pump because it will have to push a large weight of water through the hose. There is a happy medium so you may have to experiment. You may want to use more rigid hose, like water line pvc, even up to 1 inch diameter and put a garden hose connector on the end of it where you want to use the water. that worked for me when I added another 50 feet of hose on the end of my delivery pipe to drip water the garden. A soaker hose at the end worked well to drip water onto the garden for hours.
LisaFM2 years ago
I think you should get the instructable of the year award! the way you presented this is humorous, intelligent and witty and I can't wait to try to make one! Thank you so much!
el_frenchy3 years ago
For those who wants to know more about this type of pump : http://www.walton.fr/hydraulic-ram.html
They are well known in France, they have been invented by Mr de Montgolfier (who also invented the hot air balloon by the way) so you may test your french at :

another link http://energies-nouvelles-entreprises.pagesperso-orange.fr/ch12-71.htm

Once the company was for sale, I don't know if still on sale ? There is a enormous potential but need communication efforts
it was invented by the one muslim scholar, don't forget origion of EU culture/renesanse and enginering are copy of muslims culture, science and engeniring. http://www.youtube.com/watch?v=Vtgkcz87XbA
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