For decades, handpumps have been a very useful and popular tool for transporting water to the surface. They offered considerable performance for their simple design and low capital costs, especially in developing countries.
Hopefully, research and development in this area won’t stop. There are already similar, non high-tech systems that deliver high performance, don’t require humans to power them, and are maintenance-free. These are key factors, essential for their implementation in developing countries. In terms of developmental cooperation, sustainability and durability is a top priority.
Hand pump for water wells to pump water out of a well.
A water hand pump is a water well pump which pumps water out of potable – drinking water wells to a maximum depth of about 80 meters. The delivery height depends on the water level in the water well. It is running with the aid of human or animal power.
Inexpensive acquisition but high maintenance, replacement and new installation costs.
Water can only be pumped with the aid of human or animal power.
Gaskets in the pump piston system must be replaced.
Greasing and replacement of unit parts.
Maintenance with replacement work and costs.
It is easy to make replace existing water hand pumps with a new water well pump system.
The Various Hand-Pump Systems
Many people in developing countries still use hand-pumps to access safe drinking water.
Hand pumps for water wells to pump water out of a well by hand.
Main principles of hand-pumps
There are many different types of hand pumps. Most of them are ‘displacement’ pumps, and therefore have a piston. Piston pumps are fitted with a check valve (foot valve), and a pump rod connected to the piston which moves in an up and down motion, producing suction. Raising and lowering the pump handle causes vertical movement of the pump rod. When the piston moves upward, the back-pressure valve closes. This creates a vacuum underneath; the result is that the water flows through the opened foot-valve in the cylinder. At the same time, the water remains above the piston, and is pumped to the top. When the piston moves downward, the foot-valve closes and opens the back-pressure valve, so the piston can move down and allow water into the cylinder.
Water Pump Lift Height – Suction Height
The water lift-height can be divided into the following categories:
- Suction pumps 0-7 meters
- Treadle Pumps (Diaphragm Pumps) 0-7 meters
- Lift Pumps 0-45 meters
- Spiral pumps (playground pumps) 0-60 meters
The piston located on the surface of the cylinder draws the water upwards. In practice, the maximum lift-height is 0-7 meters. This is due to atmospheric pressure, which causes the seals in the piston on the surface to be rendered ineffective, leading to a loss in height. For this reason, suction pumps have a limited number of applications.
Treadle Pumps (Diaphragm Pumps)
Treadle pumps work by the contraction and expansion of a diaphragm in a closed system. The water is brought to the surface by peddling using either the feet or hands. Although the pump is easy to maintain, replacement diaphragms, which are expensive to buy, are required at relatively short intervals.
Some lift-pumps can lift water to a height of up to 60 meters, although with a small loss of water. Middle and High lift-pumps are designed to require little physical human effort to operate.
The spiral pump works without a piston, and like the High lift-pump is used for higher water lift-heights. The suction rods and the rubber stator rotate, causing water to rise to the surface. In order to maintain it, a special lifting mechanism is required.
Performance of Hand Pumps
Hand pumps are getting used worldwide but mainly in Africa, India, Asia and South America