Low Lift Hand Pump

At a glance:

Community of Practice: Water and Sanitation Type: Workshop

Duration: 1 – 2 Hours Min/Max participants: 30 for demonstration

20 for making

Room/space requirements: Large open space

Objectives

To produce a low-lift hand-pump that can be used to

pump water from a low point

EWB-UK Training

Hand Over Pack

1. Introduction

This workshop was first introduced at Small is… 2012. A very popular

workshop, it provides participants with the ability to make a low lift hand

pump which can be used to move fluids from one place to another. They use

human power and mechanical advantage to do so. They are used widely in

every country in the world for a variety of industrial, marine, irrigation and

leisure activities. There are many different type of hand pump available

however most have plungers or reciprocating pistons and are a positive

displacement.

In the developing world, water is often lifted by hand using hand pumps. In

some disaster scenarios, lifting water by hand is the most appropriate method

of obtaining water. Hand pumps can be used in dug wells or boreholes where

other water-sourcing devices such as windlass or buckets require a large

diameter hole to obtain water.

2. Typical Itinerary

The pipe can be split into several components: The piston, the Riser, the Foot,

the Handle and the Valves.

How the pump works:

The piston slots inside the riser and when ‘pumped’ water rises up the riser

and out the top of the riser pipe. The valves inserted in the pipe enable the

water to flow in one direction through the pipe.

Making the Valves:

Two valves need to be made in order to make this pipe function correctly. One

is the foot valve which is used to let water enter into the base of the pump

and the other the ‘inner valve’ which will be placed inside the piston tube.

1. Make the foot valve

A. Cut a piece of the 50mm (2”) diameter dowel/wood 2.5cm (1”) long

B. Shape the wood so it is a tight fit into the 50mm (1½”) pipe – It will

expand a bit when it gets wet so an exact fit isn’t needed but it needs to

be tight so it won’t fall out when it dries.

C. Cut a piece of inner tube the same diameter as the wood

D. Glue the rubber to one face of the wood

E. Drill seven 8mm (3/8″) holes through both the face of the rubber and

the wooden piece – These are the holes the water will flow through.

F. Cut a piece of inner tube about 2mm (1/16”) smaller in diameter than

the wood.

G. Loosely, screw the rubber onto the wood near the edge using a wood

screw – The rubber flap will move out of the way when water flows in

one direction and block the holes so that it can’t flow the other way. The

gap around the outside is so that the flap won’t get caught on the

inside of the pipe.

2. Make the Inner Valve

A. Cut a piece of the 50mm (2”) diameter dowel/wood 2.5cm (1”) long.

B. Shape the wood so it is a tight fit into the 40mm (1¼”) pipe.

C. Cut a piece of inner tube the same diameter as the wood.

D. Glue the rubber to one face of the wood.

E. Drill six 8mm (3/8”) holes through the both the face of the rubber and

the wooden piece.

F. Cut a piece of inner tube about 2mm (1/16”) smaller in diameter than

the wood.

G. Loosely, screw the rubber onto the wood near the edge using a wood

screw.

Making the Handle Reinforcing

A. Cut a piece of 50mm (2”) diameter dowel/wood 5cm (2”) long.

B. Trim the wood so it is a tight fit into the 40mm (1¼”) pipe

Making the Foot

A. Cut a piece of 50mm (2”) diameter dowel/wood 5cm (2”) long.

B. Trim the wood so it is a tight fit into the 50mm (1½”) pipe.

C. If the pump is going to be used in a tank with a plastic liner, the bottom

of the foot should be rounded so it won’t damage the liner material. It is

also a good idea to seal the rounded section with varnish or paint.

Prepare the Rising Main Assembly (The Riser)

A. Cut two pieces 20cm (8”) long off the 50mm (1½”) pipe – these will be

the spout and the top part of the rising main.

B. Cut the end of one of the 20cm (8”) lengths at 45 – This will form the

spout of the pump.

C. Take the remaining long length of 50mm (1½”) pipe and drill sixteen

8mm holes 7.5cm (3”) from one end – These holes will be where the

water goes into the pump.

D. Insert the foot valve into end of the 50mm (1½”) pipe that has been

drilled with holes. Make sure the rubber flap is inside the pipe. Push the

valve past the drilled holes so that it is 10cm (4”) into the pipe – The

height of the inlet holes and the foot valve makes sure the pump takes

its water from above the sludge in the tank.

E. Insert the foot into the end of the long piece of 50mm (1½”) pipe – The

foot will let the pump sit on the bottom of the tank without damaging

it.

F. Assemble the pieces of 50mm (1½”) pipe into the tee, with the spout

angled off and the long and short straight pipes in a line. Cement them

into place.

Prepare the piston assembly

A. Insert the inner valve into one end of the 40mm (1¼”) pipe. Make sure

the rubber flap is inside the pipe.

B. Insert the handle reinforcing into the other end of the 40mm (1¼”) pipe

and screw in with 8 wood screws. Make sure to leave a space to bore an

18mm (3/4”) hole to fit the handle between the screws.

C. Mark a line around the pipe 25cm (10”) from the end with the handle

reinforcing, mark another 20cm (8”) below that.

D. Drill a series of about thirty 8mm (3/8”) holes, evenly-spaced between

the two marks – These holes are how the water gets out of the inner

pipe to flow from the outlet.

E. Carefully insert the assembly into the rising main assembly until it just

touches the foot valve. Mark a line around piston assembly where it

comes out of the rising main assembly.

F. Remove the piston assembly and mark out a 18mm (¾”) circle with its

top just under the line just marked (in step E) – The position of the circle

should make sure the handle will stop the inner pipe from hitting the

foot valve and damaging the pump while it is in use.

G. Bore a hole through the pipe and the handle reinforcing using the circle

as a guide. The hole needs to be a tight fit for the 18mm (¾”) rod.

H. Push the rod through the hole until it is central.

3. Session Information

It is recommended that the Trainer make one before running this session to

ensure the whole making process is understood.

4. Useful Resources

https://docs.google.com/open?id=0B8xnc8oEyESuZ09JOHFoano4X0U

5. Materials

For 1 Pump:

50mm (1 ½ ‘’) Tee

50mm (1 ½ ‘’) Pipe

40mm (1 ¼ ‘’) Pipe

40cm long 15-20mm dowel

30cm long 50mm dowel (or square wood, or branches)

Wood Screws

Inner tube Rubber

6. Tools

Drill

Sand Paper/Wood File

Hand saw (for Wood and Plastic Tubing)

7. Risks to consider (to guide a risk assessment form)

Potential Risks Mitigation Strategy

Cuts from Hacksaw Instruction on fixing workpiece and

sawing technique, use of Jig

Getting Glue in Eyes Common sense

Drilling into hand Instruction of fixing workpiece and

sawing technique.