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The Canzee pump is of ingenious simplicity: it has no conventional piston or seals. It contains no significantly wearing parts and the pump needs no maintenance. The few parts that do eventually break down are very easily repaired. Ideal for installation on shallow wells, the pump is robustly constructed and lifts water from at least 10 meters.
The Canzee is unlike most other hand pumps because instead of a piston valve moving inside a cylinder, the pump uses one plastic pipe inside another to lift water. At the bottom of each pipe is a simple non-return valve, which allows water to enter the pipe, but not out again. As the inner pipe is lifted, the water in it is also lifted. At the same time, an area of low pressure is created in the space between the two valves, causing water to enter through the valve on the outer pipe. When the inner pipe is lowered once more, this water between the two valves is forced into the inner pipe through the second non-return valve. A small amount of the water is also displaced into the space between the two pipes during the downstroke, but the volume is minimal due to the small cross-sectional area and high frictional forces. However, it does mean that water is displaced from the pump on both up and downstrokes. This process continues until the water starts to flow from the pump head.
The Canzee pump needs no maintenance even when used intensively. There are no parts that need adjustment, greasing or attention in any way. After a simple training, villagers are capable to make their own spare parts and repair their pump without outside assistance.
This simple design has eliminated the need for piston seals. Instead, the non-return valves at the bottom of each pipe depend on rubber discs which can be cut from an old tyre inner tube. Under normal use, the pump will function for years without breakdown. When that finally happens, repair is easy and can be done within minutes. The pipes themselves do not wear out. A thin film of water between the two pipes ensures they do not touch: the pump lubricates itself.
The only other part that might wear out over time is the handle guide. A new one can be simply screwed in place. If this spare part is not available, an ordinary carpenter can make a spare, from tropical hardwood or any other available material.
The Canzee is delivered in kit form with 6 metres of pipe. If a greater depth is required, additional pipes are available. Since the pump is lightweight, it can be shipped by air. Each pump comes with a spare handle guide, plus a supply of rubber disc valves. Illustrated instructions are provided on how to install the pump (a very simple procedure), as well as the basic tools to do so (spanner, hacksaw and screwdriver). BushProof provides pump mechanic trainings and technical advice on request.
Previous versions of the Canzee have been tested by the British Consumer Research Laboratory, which concluded that “the overall efficiency of the pump is good with a maximum value of 43% at 37 strokes per minute. This ergonomically well designed pump compares favourably with presently available direct action pumps such as Tara, Nira and Wavin. The pump appears to have enormous potential.”
The pump is now produced by BushProof in Madagascar where several hundred pumps have already been installed. Canzee pumps have been used for years in many countries including Kenya, Tanzania, Zimbabwe and Angola. The Canzee is officially recommended by the government of Madagascar.
In the field, performance has been verified in several countries. For instance, Kenyan users report 3 years of continuous use by 200 people, lifting water from 6 metres, before having to repair the rubber disc. In Uganda 2 years and 8 months passed before the first repair, with the pump lifting from 4 meters. In Madagascar village pumps have also continued to operate without breakdown for several years.