Emergency Water Pumps

[Commons] [School] [Garden] [Kitchen] [Meditorium] [Library]
health/water-pumps.htm

These pumps are based on common water pumping techniques, and have actually been built and tested in one of the monasteries wells. These pumps are extremely simple and inexpensive to build and operate.

For those who have visited before, we have added a piston pump, and modified the plans for the bubble pump to reflect an improved design.

The Check-Valve Pump

The check-valve pump is the simplest of these pumps to make, and will pump water through a hose to where it is needed, but for the effort expended it moves less water than the other pumps. This pump can be put together in a few minutes without tools.

Parts list:

Quantity Part Estimated Cost
------------------------------------------------
as needed 1/2" PVC pipe (10' sections) $0.67 ea.
as needed 1/2" PVC couplings $0.09 ea.
2 1/2" PVC threaded fitting (male) $0.20 ea.
1 Foot Valve (One way valve) $3
1 Hose Bib $6
1 Garden Hose $5
1 PVC Cement $2
------------------------------------------------
 Total Cost $18

Tools Needed

None

Construction

Connect a long enough length of PVC pipe to reach at least three feet below the water level of your well when it is in the working position. At the top of the well, the pipe should be sticking out far enough that you can comfortably move the pipe up and down. To the bottom of the pipe connect the foot valve. (Typically with a threaded fitting.) The valve should be positioned to allow water to enter the pipe, but not to leave. To the top of the pipe connect the hose Bib. Lower the pipe into the well, and connect the garden hose. (Be sure the hose connector is opened!)

If the pump needs to be moved from place to place, or if water levels change frequently, it would be helpful to connect the pipes using threaded fittings, so they could be taken apart and reassembled.

For cold weather operation, a tiny weep hole should be made in the pipe about five or six feet down from the top of the pipe. The idea is to allow the water to drain out of the pipe when it is not in use to prevent it from freezing. This hole wastes water (your muscle power) so make it as small as possible while still allowing the pipe to drain in a reasonable amount of time. If you use threaded pipe fittings, you can remove the weep hole during warm weather.

I selected a check-valve that has a little door that flaps open and shut.

Operation

The pump is operated by moving it up and down. You have to lift the entire weight of the pipe and the water in it, so if the well is really deep, you may want to rig up some type of lever to hold the weight of the pipe.

Theory

Water is forced through the foot-valve on the down stroke, and then is held in the pipe when the foot-valve closes on the up stroke. The quicker the pipe is moved down, the more water is collected with each stroke. The speed of the up stroke does not matter.

The Bubble Pump

The bubble pump is easy to make and operate, but may not be suitable for all wells since it requires a lot of pipe under the water. It has no moving parts inside the well. This pump can be assembled in a few minutes.

Parts List

Quantity Part Estimated Cost
------------------------------------------------
as needed 1/2" PVC pipe (10' sections) $0.67 ea.
as needed 1/2" PVC couplings $0.09 ea.
2 1/2" PVC elbow $0.15 ea.
1 Large Bicycle pump $9
optional Battery operted tire Inflator $10
1 PVC Cement $2
------------------------------------------------
 Total Cost $16

Tools Needed

Saw to cut tubing

Construction

Measure how far down the water is from the top of the well.. Multiply this depth by 1.5 to find out how far under water the air outlet should be. Add these two numbers together, and then add two feet to determine the length for the longest pipe. Refer to the drawing below for details.

To make an airtight fitting for connecting a bicycle pump, we pressed  a tire stem into a 1/2" male threaded PVC coupling (See drawings). All the parts were covered with lots of PVC cement before pressing them together.

Here is the detail for connecting the tire stem.

An alternate idea for narrow wells would be to use a narrow piece of tubing to introduce the air into the bottom of the lift tube rather than use an elbow and T. You could also use what is called a street elbow, which will allow the two pipes to be much closer together, especially if you saw off 2/3rds off of each fitting before gluing them together.

Operation

This pump is operated by working the bicycle pump. The rising air bubbles lift water with them as they float to the surface. The larger the lift pipe, the more you have to pump to lift the water, but the more water you get out. Optimum pump rate for a 1/2" lift tube is about one stroke every two seconds, which yields 1.5 gallons of water per minute in our well. Pumping faster than this brings less water to the surface.

When choosing a pump, choose a monster pump if you can find one: Something designed to move a lot of air, at relatively low pressure, in a short period of time. (A raft inflator would be better than a bicycle pump.)

This pump will operate using $10 battery operated tire inflators, and for 1/2" pipe, these pumps supply more than sufficient air. (Some of the air is wasted.)

We didn't like the design of the bicycle pump we were using, because it had very narrow passages for the air to move through, though it worked well. (It was hard to pump even when it was not connected to the well.) So we modified the pump to move more air with less effort. To do so, we drilled a 3/8" hole in the side of the pump, (replacing a 1/16" hole), and welded a one way valve onto the pump. We then connected this valve directly to the well through a 1/2" coupling.

Because the bubble pump runs by air pressure, the source of the air can be located some distance away from the well. (A windmill on top of the barn could pump the air, or you could pump from inside the house to be out of the elements.) You will need 0.43 psi of air pressure for each foot of water above the outlet of your air tube.

The operation of this pump is gentle, and I often sit for long periods of time, meditating while engaging in the gentle aerobic rhythm of the pump. (We use it to fill a pond.)

Theory

This pump works because the air carries water with it as it rises through the lift tube. This pump works best when 60% of the length of the pump is submerged, so it requires a well that is deep enough to accommodate the pump.

The piston or suction pump

This is the water pumping technique used by the pioneers, and moves a lot of water in a hurry. It is the hardest of the pumps to make, and requires some tools and mechanical aptitude, but once the shopping is done, you can build it in an hour.

Parts List

Quantity Part Estimated Cost drawing 
-------------------------------------------------------
as needed 1/2" PVC pipe (10' sections) $0.67 ea. a
as needed 1/2" PVC couplings $0.09 ea. 
as needed 1-1/2" PVC pipe (10' sections) $2 ea. b
as needed 1-1/2" PVC couplings $0.47 ea. c 
1 1-1/2" PVC T $0.50 ea. 
1 1-1/2" to 1/2" threaded bushing $0.90 d
1 washer e
3 1/2" PVC threaded fitting (male) $0.20 ea. f 
1 marble g 
1 1/2" PVC threaded fitting (female) $0.20 ea. h
1 Foot Valve (One way valve) $3 k
1 PVC Cement $2
------------------------------------------------
 Total Cost $15

Tools Needed

Saw, drill, knife, pipe-wrenches, tin-snips, file, etc., depending on your approach.

Construction

We couldn't find an off the shelf check-valve that would fit inside a 1-1/2" pipe, so we designed our own.

To make the upper check valve: Drill four 3/8" holes through the side of a 1/2" PVC to male threaded coupling. Smooth off the edges of the drill holes with a file or knife. Put an appropriate sized marble into the coupling (Chineese checkers size is too small). Glue a piece of 1/2" PVC pipe into the fitting, inserting it only about 3/8" into the coupling, so as not to block the holes you just drilled.

To fabricate the washer, we took a 1-1/4" PVC to 1/2" threaded female bushing and cut 1/4" off of the threaded end of it, then filed down the 1/4" piece so that it would fit into the 1-1/2" pipe. There is a trade-off associated with the construction of the washer. If it is too big, it will rub unnecesarrily against the side of the pipe during operation and make the pump harder to operate. If it is too small, water will leak past it during operation. The washer could just as easily be fabricated from a piece of metal, or a PVC endcap, or some sort of stiff plastic.

The first verion of this pump that we made, we slid the inner pipe down the tube, and it went right to the bottom and got stuck in the space between the bushing and the end of the PVC pipe. To prevent this in following models we screwed a female threaded coupling onto the bottom of the check valve to keep it from going all the way to the bottom. This coupling is also necessary when a non-threaded washer is used. We found it helpful to cut off about half of the length of the male threads to make it easier to screw the two fittings tightly together.

We attached the bottom check valve (from top to bottom) through means of a 1-1/2" coupling, a female 1-1/2" to 1/2" threaded female bushing, a 1/2" threaded male coupling, a short length of PVC tubing, and another 1/2" threaded male coupling. If we could find such a thing as a male bushing, it would have required fewer parts.

At the top of the well, we attached a 1-1/2" T to divert water horizontally. (The 1/2" pipe goes right through it.) We attached a 1/2" T and a couple of 6" lengths of PVC pipe to the top of the inner pipe to make a convenient handle for the pump.

If this pump is to be used in freezing weather, a weep hole should be installed about six feet under the top of the well.

Operation

This pump is operated by raising and lowering the inner pipe. Water flows up and out through the outer pipe.

Theory

When the inner pipe is raised the top check-valve closes, and water flows through the bottom check valve, and out the top of the pump. When the inner pipe is pressed down, the lower check valve closes, and water flows through the upper check valve.

This pump can be operated either as a suction pump, or as a piston pump, depending on where you locate the upper check-valve. If you locate the check-valve near the top of the well, above the water level, it will be operating as a suction pump. If the upper check-valve is located below the water level, this pump is operating as a cylinder pump.

Suction pumps require priming before use, and will bring water from as deep as about 20 feet. Cylinder pumps are self priming and will work at any depth.

Questions and Answers:

How deep will these pumps work to?

In theory, as deep as you like. In reality, there are some practical limits, for example if it is 60 feet down to the water level, then the bubble pump needs 90 feet of pipe under the water. Many folks wouldn't drill an extra 90 feet after they hit a reliable source of water...

With the check-valve pump, you have to lift the entire column of water with each stroke, so it eventually gets too heavy to move. You could rig up a lever to support the weight.

Perhaps the main limitation on these pumps is that they are operated by people power.

How Deep is your well?

We are pumping water from about 9 feet below ground level.

Which is easier to use?

The bubble pump is easiest to use. The piston pump moves the most water for the amount of effort expended.

Other Sites

A visitor pointed out to us that Noah's Ark has plans for a check-valve pump. Please visit http://www.millennium-ark.net/News_Files/INFO_Files/Hand_Pump.html since the plans are very nice, and there is more detail about performance than we have here. The site says that check-valve pumps remain workable down to about 75 feet, at which point they become too heavy for one person.

Permission is granted to copy and distribute these plans for non-commercial use.
Please retain this notice with each copy.
Joseph Absalom

[Commons] [School] [Garden] [Kitchen] [Meditorium] [Library]
health/water-pumps.htm

Archive/Mirror Of: The Absalom Collection