Picture of Hydraulic Ram Pump

Pump water with no electricity, no gasoline, just gravity!

Sound crazy or impossible? Don't worry, it does obey the laws of physics, but I'll try to explain the operation later. This instructable shows how to build a fairly simple water pump that needs no energy input other than water flowing from a higher point to a lower point. Most of the pump is constructed from PVC, with a couple of bronze pieces thrown in for flavor. I was able to source all of the parts from a local hardware store (Lowes) for a bit under $100.

To function, the pump does require a reasonable amount of water that will drop at least 3'-5'. The level that the pump can raise water to depends on the water's head (total drop the water will make).

This design was worked out by Clemson University.

If you like what I've done, please take the time to give it a rating, and I'd love to hear your input. Thanks!

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Step 1: Bill o' Materials

Picture of Bill o' Materials
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Before you can really do much, you've got to go out and buy some stuff. One of those sad facts of many projects. But if you want to build this (and it's a lot of fun to see it work), print out this list and head to the plumbing dept of your hardware store.

Materials for the Pump
  • 1-1/4" valve
  • 1-1/4" tee (buy two of these)
  • 1-1/4" union
  • 1-1/4" brass swing check valve
  • 1-1/4" spring check valve
  • 3/4" tee
  • 3/4" valve
  • 3/4" union
  • 1-1/4" x 3/4" bushing
  • 1/4" pipe cock
  • 100 psi gauge
  • 3/4" x 6" nipple
  • 4" x 1-1/4" bushing
  • 4" coupling
  • 4" x 24" PR160 PVC pipe
  • 4" PVC glue cap
  • 3/4" x 1/4" bushing
  • Short (4') section of 1-1/4" PVC pipe
  • Old Bicycle Innertube
This parts list comes directly from the Clemson website. I recommend you look there for help in identifying what each of the pieces look like, if you're unsure. I'm also not convinced that the 100 PSI gauge, or all of the things that make it possible, are necessary. This will probably drop the price a good bit, and I haven't found a need for it on my pump. The associated pieces are: 100 PSI gauge, 3/4" Tee, 3/4" x 1/4" bushing, the 1/4" pipe cock. Four things not needed. But have them if you like.

Connections Note Read through the instructable and understand all the pipe-fitting connections that will happen before buying materials. The store may not have exactly what you're looking for, and you may have to improvise. I wound up getting some different parts because my local store didn't have the exact parts I was looking for. This usually appears in the form of not having a threaded fitting, but having a smooth pipe connection, or vice versa. Not a problem, you can figure it out.

Installation Materials
  • Long section of 1-1/4" PVC ("drive pipe", connects pump to water supply)
  • Garden Hose (male end threads into 3/4" union, supplies pumped water)
  • Bricks, blocks, rocks to prop up and anchor pump
  • Shower Drain assembly (must be able to attach to 1-1/4" pipe, for attaching pipe to water supply)
Build Materials and Tools
  • PVC Primer (I used Oatey Purple Primer)
  • PVC Cement (Oatey again, just what they had)
  • Teflon Thread Tape
  • Hacksaw
  • Measuring Tape
  • Clamps
  • Pocket Knife
  • Lab gloves (keeps the chemicals on the pipe and off your hands)
  • Bike Pump (to inflate the innertube)
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If I build the ram and set it 15' down in my lake, will it pump water straight up an additional 5 ' to a holding tank?

Thanks :) wont.

magfree3 months ago

Can I put an inverted u-tube at the top of the standpipe to keep debris out? If so can I restrict it from 4" or 3" to say 2"?

habolooby (author)  magfree3 months ago

While I'm not entirely sure I'm imagining the right thing, I would say that you likely could put an inverted u at the top of the standpipe. However.

I'd hesitate before restricting the diameter. As you decrease the diameter of the pipe, the cross-sectional area will decrease by the square of the change, & the volume of water that can pass through at a given pressure will also drop. If you look up some of the calculators online, you'll see that the diameter of the standpipe is important.

Ultimately, I'm not sure the inverted u would filter debris - but if you leave a comment with a bit more description of what you're thinking of, I'd be happy to think about it.

magfree habolooby3 months ago
Thanx for your answer, habolooby. I live in an oak forest. If I install two 90's at the top with the opening facing down, I could avoid leaves and branches falling into the opening. 3 and 4 inch 90's are expensive. I thought I might accomplish the same thing by reducing the diameter of the pipe first.
habolooby (author)  magfree1 month ago

I don't know if this image will work, but this is what I imagine you're thinking of. Figure A is your plan. To filter incoming water, you'd make a U out of two 90's and a T joint, with the 90's pointing down into the water. I'd be wary of anything that restricts flow into the pump. Instead, you might consider figure B. Here you would cap a piece of culvert, large pipe, a barrel - anything big really, set it so it's ~ 3/4 in the water, give it a vent on top, and have the stand pipe draw water from inside the cylinder. Bottom of the barrel / pipe / whatever is open to the water. Sorry for the crap quality, it's what I could come up with in ~15 minutes between work things. Let me know if you have questions.


I was referring to the stand pipe used to compensate for friction when your supply line is more than 100 feet.

Thanx for the info though.


The stand pipe coming out of the water has a cap. I'm not sure if that is what you are talking about but the big pipe acts just like the pressure tank for a well pump.
hulk13711 month ago
Something to consider for the waste valve is a modified foot valve for a well. The valve can be disassembled and the valve turned to work in reverse. I prefer this method because you can add weights to the valve that control how much pressure is needed to close the valve. I feel like this type of valve will hold up longer than a swing gate valve as well.
habolooby (author)  hulk13711 month ago

I'm not very familiar with well foot valves, but I have seen designs for ram pumps that had adjustable waste valves. Sounds like what you're describing, and it has that nice tune-ability feature. Hardware store parts used here for simplicity, but by all means modifications and improvements are encouraged. If you have any photos / drawings of your approach, please post them - or make an instructable! I'd be happy to post a link or something on here.

They are available at hardware stores. Well here anyway. I can post a picture of the modified one when I can get down to it. I don't have it in the water now because of the cold weather.

Hi there. If you are pumping up to a tank, can you use a ballcock at the tank so as not to waste water? I assume the pipe pressure would equalise and stop the pump when the tank ballcock was shut, but wondered if when the ballcock opened again and the output pipe pressure dropped the pump could restart itself? I would appreciate your thoughts.

habolooby (author)  beck.hazlett1 month ago

I'd agree with hulk1371's response, and would add that if you were put a valve at the end, closing it would be similar to raising the outlet pipe to an elevation higher than the pump could lift water. The pump would pressurize the system a bit, and then cease to cycle. Opening the valve would relieve pressure on the outlet side, but it is unlikely that the pump would spontaneously restart. You'd probably have to go and give the waste valve a poke. Hulk1371's advice is spot on.

You tank should not be sealed air tight. If it is a large tank it would take a long time to build that much pressure though. You need something to run off excess water when the rank is full. The best setup is a top fed tank with the valve a little off of the bottom. (you want somewhere for sediment to go) you also want a clean out on the very bottom for when the sediment builds up. At the top of the tank you want a pipe that has a check valve to allow water and air to escape without allowing everything else in. The overflow should run to somewhere that you don't mind water draining too.
hulk13711 month ago
I do not want to take away from this excellent instructable but I think you under estimate the value of the drive pipe. This makes all the difference on the overall effectiveness of the ram pump.
habolooby (author)  hulk13711 month ago

I'd agree completely. The drive pipe (and available elevation drop) are pretty much determine your energy source. Didn't mean to undersell it!

Thanks for your post.... I'm so grateful with your great idea.... I will try to produce one sample in order to help a particular community where we constructed a Masjid(place of worship) here in the Philippines.

Hi habolooby this is a great find. Thanks for posting. I have a fast flowing stream with about 1.5m head needing about 30m of drive pipe. The outlet pipe is about 60m long and will feed a dam maybe 1m above the high point of the drive pipe.

a) what sort of life expectancy do these pumps have (ignoring damage from river debris) and

b) how do you keep the water filtered at the intake - do you need to fit a filter for river applications? Assuming "yes", does the pump self clean the intake filter with a backflush when the pump stokes, or do you have to vigilantly inspect and clean?

Thanks in advance for your reply.

habolooby (author)  michael.herman.142683 months ago

Sounds like a good place for the pump, I hope it works out well!

As to your questions - I'm sorry to say I don't have a good answer for the life expectancy. As something with only two moving parts, I'd hope it lasts for a good while. I haven't had the one I made in continuous operation - I'm not around the farm much these days. Might post the question as a reply to some of the other commenters who built these.

I would filter the intake. A large screen filter creating a bubble around the intake would probably be best, so it doesn't decrease the intake flow rate.

Can the output pipe from the ram pump drop in elevation before it makes its rise? For instance can the output line drop down a canyon before climbing the other side?

habolooby (author)  garrity.ocrowley3 months ago

Short answer is yes.

It may affect the start-up operation of the pump, but in steady state is should be fine. Water finds its own level, and all the pump cares about is what back pressure it has to work against. If if spring check valve doesn't have a little pressure behind it to accelerate it when it closes, I think the pressure at the swing check never gets low enough for it to open, and the pump gets stuck. You might have the outlet pipe make a short elevation run before diving through the canyon etc.

If you're doing a super long run in small pipe, you might lose some flow to friction in the pipe, but typically the water in the outlet pipe flows slowly enough for this to be negligible.

gideonfox2 years ago
Thanks! it works great!

I was wondering if spring check valves with more or less psi requirements make a difference; one spring check valve i found had a small week spring in it and others required some force to open? The one i used which you may have used, was one i picked in-inbetween the spring strengths i found. 

habolooby (author)  gideonfox6 months ago

The strength of the spring will determine at what pressure difference the valve closes, but I don't think it has a major impact on function. I have seen other designs that have adjustable versions of the swing check valve. This lets you determine how fast the water must be flowing before the valve activates, and thus how much pressure you build up. Here this element can be slightly adjusted by rotating the pump along it's long axis, changing the force of gravity on the swing check valve.

shaileshp6 months ago


I'm planning to use it to pump water upto 1 KM at ground level from creek to prawn pond, will it success ? need calculation formulas ? pond is around 3 Acre , need to recirculate water. I may need multiple pumps can you guide me ?

habolooby (author)  shaileshp6 months ago

Sadly, I don't have the time to provide and explain the formulas, but I'll do my best to help here. The main concern the ram pump has is resistance. This is usually answered by how high it needs to pump water, that is how much pressure it must overcome to get water across the spring check valve. If your pond is at the same elevation as your pump, you will need to consider the resistance your 1 km of pipe will produce. This is a whole separate set of calculations, but is easy enough. If the pond is higher than your pump, you'll have to take the elevation change into account. If the pond is lower... skip the pump and just run the pipe! Hope this helped, and some time spent searching the internet should answer your calculation questions. Good luck!

jo99999910 months ago

So i am planning on building a two tiered pond with water fall, and thinking about using this. would it work if instead of water pulling out of the check switch valve it poored back into the lower tier of the pond?

habolooby (author)  jo9999996 months ago

I'm not sure I entirely understand your plans, but here goes. The
essential function of this device is that if you have water falling some
distance, a small portion of that falling water can be pumped higher,
and the rest will continue on to a point lower than the source. However,
if you're thinking of the perpetual waterfall, I'm afraid that's still
just a good optical illusion :)

MattL27 months ago


Sweet find and good job publishing for us, although I'm lost as to what the purpose of the 1 1/4" union is. Can you explain?



habolooby (author)  MattL26 months ago

The 1 1/4" side of the pump needs to be connected to a stand pipe, which tends to be rather long and cumbersome. The 1 1/4" union allows you to disconnect the pump from the stand pipe, so it's mostly for convenience. If you're installing a pump and have zero intention of moving it, you could probably skip it. Thanks for the question!

This ram pump was a very brilliant project, I am planning to build one here in the Phils. more power to habolooby and God bless!!

Parabéns, muito bem desenvolvido e custo beneficio excelente.

I don't know if anyone is still monitoring this post but I have a question. Forgive my stupidity I am a city boy. I presently live on the intracoastal in a 5th floor condo. If we had some kind of crisis and I needed to pump brackish water up to my condo, is that even possible. Without any electricity (crisis) and the need for water I am wondering if it would work. I know I would have to to use reverse osmosis to filter the water but I have a 92 yr old mother who i care for and want to be prepared if a crisis comes. Anyone know? If it wouldn't work any ideas?

habolooby (author)  BuffJackson1 year ago

Hi! Still keeping an eye on this - I
feel terribly guilty about not having time to post any further
instructables, so I try to make up for that by answering questions here.

As for your question, this sort of pump requires relatively fast
moving water through the pump with some force behind it. I think there
might be easier & more reliable ways of keeping your condo hydrated.
The only intercoastal I know of is in Florida, so we'll assume you're
at decent risk for hurricane type crises. There are a lot of high
quality resources out there for preparing a hurricane emergency kit. The
fact that you're working on preparing for something like this is great.

Water is critical for survival. People can go for quite a while
without food, but things get ugly quick without water. Stockpiling water
can be a good idea. Survival guidelines recommend a gallon per person
per day. The WHO PDF has a good explanation. Depending on what your roof /
outdoor access is like, you might be able to set up a tarp and collect
rainwater with it.

Ultimately, I'd suggest starting over at, and then gathering the gear for the kit recommended by FEMA.
It has some really helpful reminders, like prescription medications
(likely very important for a 92 year old). After that, you can work on
ways to source more water during a disaster. Good luck!



FEMA kit:

OK I have a question that I dont seen to have been able to get a decent answer to as yet...maybe someone here can help...?

My situation is that I have a small stretch of riverbank attached to my property that is pretty much flat.
I am not allowed to put any tubes or pipes into the river, but have the right to channel some water onto my property for use in irrigation etc.
The house is perhaps 30 or 40 meters higher than the water source, and the gravity fed storage tank another 5 meters above that.

So my question is, if I were to channel the water into a long shallow resevoir with a capacity of between 7 and 10 thousand liters, and include a controlled outlet pipe of proportionate dimensions at the furthest and lowest point, would the accumulated weight of the water exiting the tank be usable for a ram pump, given that the pump will be pretty much horizontal to the outlet pipe, with little or no run of pipe from the tank to the pump ?

I look forward to your responses as my brain is getting mashed from reading and reading and reading into this subject, and maybe now I can just get some straightforward answers...
How much drop will you have?
I have read 40 to 1 is possible. 40 up for one down but plan to use a lot of water and get very little water up. You might use between 40 and 100 liters for every one liter you pump up. You might use a lot more. But for that height you will need a design that has some adjustment. So that you can adjust the speed of the water ram. Habolooby did a good job on this, but for your needs, I think you will have to have an adjustable check valve.
cod16282 years ago
Can the Spring check valve be replaced with a swing check valve? I don't see the purpose of the spring valve, normally a spring valve is used in the vertical position...Are the two supposed to be swapped?
habolooby (author)  cod16282 years ago
Hi! So the swing and spring check valves are in the correct places by this design, but it might work if you swapped them.

A couple nice things about their current locations: You can vary the cycle rate of the pump by rotating it between pressure chamber pointing toward the sky (force of gravity parallel to motion of swing check valve) and pointing to the horizon (force of gravity perpendicular to swing check valve). If you had a spring check here, you would have to vary the spring pressure in order to change the cycle rate. This has been done on other pump designs, but is best accomplished with a home-built spring check. Doable, just adds to the project a little bit.

The nice thing about the current spring check location is how it closes once the pressure across it approaches equilibrium, rather than requiring backflow. To me it seems like this helps the efficiency of the pump, but I could very well be wrong about that.

I'll close with the same request I think Instructables lives by - try out your ideas, make some changes, let us know how it goes! And thanks for reading.
ewolvin2 years ago
Could I make this pump smaller using 1/2 inch ?
habolooby (author)  ewolvin2 years ago
I believe so. But as the diameter decreases, cross sectional area decreases (by the square of the change) so your flow rate will drop. Smaller pipes will also exert a proportionally higher frictional drag on the water, etc etc. So it's possible, but the pump may have reduced output / lift / something along those lines. But if you've got the time and materials, please try it out and let everyone know how it goes!
Nate Waller2 years ago
hi need a ram pump. i have about 10 gpm of water with about 15 to 20 foot of fall and I need it to go about 130 foot vertical. well the plans you have here work for me.
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