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Hello,

There are quite a few people who are interested in building ram pumps for
different reasons so I am writing up this follow up post with my design and
rationale and a few links that I found useful.

To start, I want to raise water about 16' from a creek that flows
throughout the summer to a 275 gallon tank that I can use for irrigation
purposes. The creek does not have much fall to it so I had to do a small
amount of damning with some field stone, though far less than my local
beaver friend. I have been looking at building ram pumps for probably two
years and have spent probably 40 hours or more online looking at different
models/designs and watching Youtube videos. There is a lot of good
information out there.

Here is a quick summary of the basic concept of a ram pump. Water flows
down a drive line and out the waste water valve. After enough pressure
builds up the waste water valve slams shut and the sudden block creates a
"water ram" which is a shockwave of pressure that runs back into the drive
line. The air filled pressure tank compresses much easier than the water
filled drive line and so water is forced past the check valve and into the
delivery line. After the pressure is released, the waster water valve fall
back open and the process repeats itself. (See attached pictures)

There are two basic configurations that differ by where the waste water
valve (or impeller valve) is located. One configuration places the waste
water valve on an elbow at the very end of the drive line right after a T
that goes to the pressure tank. The option is to locate the waste water
valve on a T before the check valve that leads to the pressure tank. I
spent many hours trying to figure out which was the most efficient system
and finally came across one research paper that said that at least at a
small scale it doesn't make much difference. I decided to go with the waste
water valve at the end of the system because the concept behind the water
ram is to create the largest possible shockwave when the waste water valve
closes. With the waste water valve at end of the system there is no back
flow from the water hitting the check valve to slow down the water coming
in from the drive line.

The sizing of my ram pump with a 1" intake/drive line comes mostly from
cost and because I don't need to move that much water. The largest cost for
the pump were the 1 1/4 inch foot valve and the 1 inch check valve. I used
a slightly large foot valve than the rest of the system because in my
research I had heard that by allowing more water to move quickly out of the
system through an enlarged waste water valve it is possible to create a
larger shockwave when the valve closes. I also chose foot valves and check
valves instead of swing valves because it is possible to alter how quickly
they close by adding spacers or weights to them. I also chose a foot valve
instead of a check valve for the waste water valve because they are
inexplicably cheaper.  I chose brass instead of plastic for longevity and
system control. I used a 1" PVC drive line instead of plastic irrigation
pipe because the rigidity of the PVC is suppose to help push the shockwave
of the water ram into the pressure tank instead of the drive line just
expanding under pressure. It also keeps air pockets out of the drive line
which can make the system not function as well. I have seen videos of many
systems that use black plastic irrigation line to run much longer distances
and they work quite well so it really just depends on the system begin
designed. If you use irrigation line you just have to be sure there are no
air pockets in the line.

I built my own pressure tank using a 2 inch PVC tube that I already had on
hand and fitted it with a 2 inch cleanout on top. I was concerned that the
cleanout would not hold air, which it did not, but it does allow me to
access the pressure tank without taking it off the pump. The pump actually
did run even though the cleanout bled all the air out of the pressure tank,
it just did not move very much water. So I put an inflatable ball in the 2
inch pipe and now the system is working much better. I think that I can get
to be even more efficiency with a different kind of air bladder in the
pressure tank. I think the ball is too small and has too much pressure. I
need something that fills the 2 inch pipe with more air and creates a
better pressure balance. The idea is that the air is there to be easily
compressed by the shockwave created by the water ram. So too much air
pressure is actually detrimental to the efficiency of the system.

The check valve and the foot valve both had to be modified by taking the
spring off the valves, which hold them closed. I didn't initially take the
spring off the check valve that went to the pressure tank but even the
slight amount of added pressure by the spring greatly decreased the water
going to the delivery line because my system is so small. I also had to add
an overly large nut, essentially as a thick washer, on the foot valve to
decrease how far  it can "open" because there wasn't enough pressure coming
from the water in the delivery line to close the system without it. If I
had two washers it would work better because right now the ramming action
happens a little too quickly and I think I am losing some potential
shockwave power.

I bought the check valve and foot valve at Tractor Supply and the rest of
the parts at Paris Farmer Union. My local Tractor Supply did not have all
the irrigations connectors which is why I used different stores. All told I
spend about $100 on the pump not including the 275 gallon tank which I
bought off craigslist for $75 (what a find!) and the 3/4 inch irrigation
line that runs to the tank. It is possible to make the same size system for
significantly less by using PVC pieces that are glued together instead of
screwed together and by buying valves through other sources. I just saw
that Brookdale Farm in NH has very good prices on valves! I chose to screw
it all together incase I want to alter the design at all. It is possible to
find everything you need at your local hardware store though it may be
slightly more expensive. I did also look at buying everything online but it
was actually incredibly difficult to find all of the connectors I needed
this way.

Here is a link to a Youtube video by Bohumir Stehlik where he describes how
to build a similar sized ram pump: 1'' RAM PUMP - almost 5000L per day - DO
IT YOURSELF, step by step - YouTube
<https://www.youtube.com/watch?v=8H8eqHznzVI>

I found his videos to be extremely informative and easy to understand. He
also has one that compares check valves, foot valves (he calls them
something else), and his homemade valve for waste water. The homemade one
works the best though I think the foot valve we can buy here is practically
the same design as his homemade one so that is what I ended up going with.
I think his videos on ram pumps are some of the best ones I found. He also
is a classical pianist so if you enjoy piano music, he is also worth
watching.

The NRCS also has a lot of information on ram pumps. Here is just one link:
Hydraulic Ram Pumps (usda.gov)
<https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_041913.pdf>

And finally, I am attaching a few pictures that show the system that I
built.

I hope this information is useful for people who are interested in ram
pumps. I have built all of one but I did a lot of research on them and am
happy to answer more questions if people have them. Probably my best advice
if you are thinking about building one is just buy the parts you think you
need and build it. They are a surprisingly simple and power free way to
raise water.

Thanks,

Nathan Hammer
Firefly Fields
802-522-4261