How to Build a Water Pump

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Close-up of waste valve.
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Pumping water is a main concern for any home or farm because, short of gravity feeding, it requires a ridiculous amount of energy.
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Waste valve (exploded view.)
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Rubber pieces (beside their metal siblings) cut from tractor tire tube.
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Waste valve bushing with 4 strap drilled and welded in place.
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Close-up of check valve (notice arrow on brass casing) and copper wire in snifter hole just below the valve in center of nipple.
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Water pump ram's design.
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Diagram of working water pump.
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Assembly of water pump.
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Materials list for water pump.

Learn how to build a water pump, the next best thing to perpetual motion. (See the water pump photos and diagrams in the image gallery.)

How to Build a Water Pump

Pumping water is a main concern for any home or farm
because, short of gravity feeding, it requires a ridiculous
amount of energy. After surveying our new land, we knew
there were several springs available–a large creek as
well as a river. The houses we had rented previously all
were spring fed so we knew digging a well was an
unnecessary expense and hassle given the bountiful water in
the area. None of the springs, however, were uphill from
either the house or garden spots. We would need a system to
pump from a gathered spring. Some brilliant idea had to
come to our rescue, something that represented a
technological triumph over adverse circumstances. That
brilliant new idea proved to be one that was a few hundred
years old.

The ram uses the force of water running downhill from a
cistern or dam to pump that water to a site higher that the
original source … without electricity.

The hydraulic ram was a familiar sight in this country
before electrification became widespread. A non electric
water pump with only two moving parts, a waste valve and a
delivery valve, the ram is a prime example of how some
homestead utility problems are solved more appropriately
and reliably by older but well-proven technology than
mainstream electrified alternatives so fully trusted today.
With just those couple of moving parts that rarely wear out
and are both easily replaced if they do, this pump is that
rarest of technological investments, one that both lasts
for generations and is virtually maintenance free. An
additional plus: it can be built by the average person in a
remarkably short time for around $100, depending on costs
for plumbing supplies in your area and what kind of usable
junk you keep around your place.

This gadget made its way into my world as our family was
closing on the purchase of our homestead here in the Blue
Ridge Mountains of Virginia. Remaining off grid was our
intention from the start–a choice which carried with
it the need to look at how we would power all aspects of
the homestead right from the beginning.

As we began to plan and purchase our solar electric
installation, it became evident that running an electric
pump was financially out of reach. Electric pumps suitable
for our situation were costly, but worse were the costs of
an increased number of panels, a larger inverter, and an
excessive run of electric lines to operate that type of
pump. We had to rule out such a system.

Research turned up a few alternative energy books dating
from the seventies with brief articles on ram pumps.
Discussing days past with old-timers at the weekly jamboree
at Cockram’s General Store revealed a little more
information on the subject. Mostly, however, the older
crowd focused on the thrilling “CHUCHUNK” that “boomed
through the holler” when a good-sized ram was operating.

Although several sources discussed the ram in detail, a
clear explanation by picture, description, or discussion of
how the machine operated was elusive. Perhaps I was just
dense, but until I began building my first ram, the entire
operation of the machine remained a mystery to me.

How the Water Pump Works

The hydraulic ram uses the force of water running downhill
through a pipe to then pump some of that water uphill to a
site higher than the source. Ex-physics students will no
doubt be wrinkling their noses in hesitation after that
remark, but bear with me. Water enters the system by
running from some source (a spring cistern or dammed creek
for example) into an intake pipe. The water moves downhill
through the pipe some distance, enters the pump, and then
exits the pump (and therefore splashes out onto the ground)
through an open “waste” or “clack” valve. This produces a
moving column of water. By allowing the column of water to
flow downhill freely through the waste valve the kinetic
energy of the moving water is prepared to work the pump.
Eventually the flow of this water increases to a point that
overcomes the tension of the waste valve spring and the
clack (the rubber part of the waste valve) closes. By
abruptly stopping the flow of the column of water, a tremendous pressure is created. This pressure can’t very
well back out the inlet pipe, rather it is led through
another pipe, through a one way “check” valve, and into a
compression chamber. The compression chamber is simply a
length of pipe capped at the top which remains partially
full of air. The water whooshes past the check valve with
all its fury squishing the air in the compression chamber
until the kinet is energy is converted to, and rests for an
instant as, potential energy in the form of compressed air.

Next the compressed air pushes the water back out of the
compression chamber with all the energy it has stored.
Since the check valve is a one-way valve, the water being
forced backwards cannot return from whence it came;
therefore this water is forced through the exit gate valve
and into the delivery pipe, thus traveling uphill as far as
the energy from the compression chamber will take it. This
water continues to move as the ram cycles with the waste
and check valves opening and closing and eventually reaches
its uphill destination.

When water and air are compressed together, some of the air
mixes with the water. Because of this, air must be
reintroduced to the system constantly or else water leaving
the compression chamber will take with it all the air in
the pump, thus ceasing function altogether. To avoid this
problem, a small “snifter” hole must be present below the
check valve so that each cycle brings a gulp of air into
the system which rises into the compression chamber and
keeps the machine from water logging.

Water Pump Site Analysis

First, explore your site to see whether or
not it is suitable for a ram. You can harness almost any
significant flow and fall to run a ram of one size or
another. Problems may arise, however, when you figure the
volume required of a system and the delivery height.

The formula for figuring these things is about two feet
long. If a little physics study in the library is more time
than you can devote right now, local engineers will be able
to conduct a site analysis, including computer-generated
plans for a set of numbers from your specific site. They
will ask for the amount of fall from the source to the pump
station, amount of water available from the source, height
to be delivered, and amount of water needed at the delivery
site (among other things) and then they calculate all the
necessary aspects of your pump and system. Their results
tell you in extreme detail the measurements of everything
from drive pipe diameter, waste valve size, angle of drive
pipe to the length of delivery pipe and its
diameter–everything necessary to maximize the
efficiency of your particular installation.

For those more inclined to build and tinker without a great
deal of mathematical forethought, the ram shown here will
operate under a substantial range of applications. It is
intended for an input flow of 5 gallons/minute, a driving
drop of 20 feet, and a delivery height of 100 feet. With a
new, highly efficient delivery valve (see source list), it
will provide more than 1,000 gallons/24 hours, but with the
check valve listed that drops to about 250 gallons/24
hours.

You may increase the size of the ram by upping the size of
the various pipe fittings which, generally speaking, will
enable the ram to pump more water since more is available
to drive the pump. Any small- sized ram pump can operate
under a fairly wide range of circumstances, but poor
efficiency is always the cost of off-sizing.

If plenty of water is available at a site with a nice drop,
then efficiency may not be important. Also, on this model
the tension of the spring and the depth of opening on the
waste valve are adjustable, making adjustable the speed of
the cycling of the pump. This allows efficiency to be
improved by means other than simply pump sizing.

One other possibility for system design is to run two rams
in parallel, thereby doubling output. Of course a site
would require adequate water. to drive the pumps in this
configuration.

Building the Water Pump

Now that the operation has been explained,
building the pump will make more sense. To build this
average-sized ram you will need:

The only part of assembly more complicated than screwing
pipe fittings together is constructing the waste (clack)
valve. This waste valve is a modification of a very
dependable design promoted by VITA (Volunteers in Technical
Assistance).

The first step to making the valve is to take one of the 2 inch by 1 inch bushings and have a smooth surface machined inside
where the rubber washer/seal will bear against it when in
the closed position. The machinist here in
town does mine for $10, which is probably a reasonable
average to expect most anywhere. While at the shop, for
those who don’t have the facilities and experience to cut
and weld metal, have 4 inches cut off the 40 inch piece of 1-1/2 inch by
1/8 inch strap and have it brazed or welded in place on the top
of the bushing close to, but not covering, the 1 inch threaded
hole. The galvanizing needs to be ground off the bushing to
allow the brazing or welding to hold properly. Drill two
1/2 inch holes through the small strap on the bushing that
correspond to two of the same size at one end of the 36 inch of
strap still remaining, so the two may be bolted together
with a piece of rubber between them. A drill press makes
this process easier, but it can be done with a hand drill.
Next, make a mark 16 inch from the end with the two 1/2 inch holes
and bend the strap around a 1-1/2 inch pipe, centering the
mark in the bend to make the waste valve spring. Drill two
1/4 inch holes corresponding to one another at the top and
bottom of the spring, right where it flattens out after the
half-circle bend to allow for one of the 1/4 inch by 3 inch bolts to
pass through both holes. Add two nuts, one to adjust the
tension of the spring and the other to act as a lock nut to
keep the adjustment from moving during operation. Two more
holes must be drilled and then the hard part is over. Bolt
the spring in place to the bushing with the two 1/2 inch bolts
finger tight. Make a mark in the center of the strap
exactly where it passes over the center of the 1 inch in the
bushing. Make another mark beyond the first toward the end
of the spring directly over the far edge of the bushing.
Now unbolt the spring from the bushing and drill a 1/4 inch
hole at the mark towards the end of the spring and a 3/8 inch
hole at the mark made directly over the bushing’s opening.
To complete the waste valve, cut a piece of rubber (I use
tractor tire tube for all the rubber pieces needed in this
ram) large enough to sandwich between the waste valve
spring and the stud it bolts to on the bushing. Cut holes
for the two 1/2 inch bolts to pass through and then bolt the
spring tightly in place using a lockwasher under each nut.
Take the 3/8 inch bolt and place on it a 3/8 inch flatwasher, then
the 1/2 inch flatwasher, then a piece of rubber cut into a 1-3/8 inch outer diameter circle, then the other 3/8 inch
flatwasher, and finally the length of copper pipe. Pass the
fully loaded bolt through the machined bushing and then
through the 3/8 inch hole in the spring. On the top side of the
spring, add a lockwasher and a nut and tighten snugly the
whole works.

It is imperative that this part of the valve open and close
in perfect alignment so that the rubber washer closes
completely on the machined surface inside the bushing and
that it not bump or rub the side of the bushing in any way
as it opens and closes. Slightly bending the spring or bolt
works to tweak out a valve not perfectly aligned. Finally
add the 1/4 inch bolt through the final hole left in the spring
to make the opening depth of the waste valve adjustable.
Add a piece of rubber over the head of the bolt by cutting
two holes and pulling it down the bolt and over the head to
reduce shock to the spring and help reduce wear.

The waste valve is now complete and needs only to be
screwed into the system. Next, take the street bend and
drill a Clinch1/16-inch hole just below the threads on one
end. Take a small piece of copper or brass wire, bend it
into a cotter pin shape, place it in the hole, and then
spread the pin ends so it stays in the hole but may move
around freely. This both prevents scum buildup and deters
the tiny bit of water that will escape from the snifter
hole from flowing out in a stream. To put the pump
together, find a vice and a pipe wrench. Using the diagram
and photos as a guide, wrap all male threads well in Teflon
tape and screw the pump together a piece at a time. Some
people pour a bit of concrete over the bottom of the ram to
hold it fast while operating. That is not necessary for a
little pump like the one described here. In fact, keeping
the unit portable may be useful on some homesteads.

Water Pump Installation

Be creative with your installation site and use common
sense to guide the construction of your pump’s environment.
If the ram is pumping springwater, it should not freeze
under even bitterly cold conditions. If, however, it were
to stop running, then it would certainly freeze and break.
Placing the ram in an in-ground structure or likewise in
some concrete or stone spring house type structure will
prevent freezing under any conditions. Also, bury all
system pipes below the frost line to avoid wintertime
problems.

The only other major advice to follow is to make a nice
intake screen at the source. Frogs, leaves, and the like
can stop a ram dead and have you disassembling the whole
mess to figure out the problem.

Tinker with the spring tension and clack opening
adjustments to get the right ram speed for your particular
installation. The slower the pump cycles the more water
gets pumped per stroke, but the more water is necessary for
operation. If the ram action stops after a bit then you may
need to speed the pump up a bit by loosening spring
tension.

Aside from foreign matter entering the system, little can
halt your ram pump. I know of one configuration that has
been running for six years without fail and I have heard of
many going fifteen years without clack replacement. In the
right situation the ram far outperforms its electrified
cousins and it’s an investment of time and money with a
guaranteed return rarely seen in the world today.

For information on site analysis, contact New Dawn
Engineering (Floyd, VA).They offer a model of an ultra-efficient
delivery valve which greatly increases the ram’s power.
Moonlight Solar (Christiansburg, VA) is the only other alternative energy company carrying the
valve in the United States. They also plan to feature a
versatile air compressor attachment for hydraulic rams,
available hopefully by the summer. You may wish to inquire
about the progress of that when you call.