For lifting of drinking water from boreholes and wells, often used external centrifugal pumps of the type “don” or “Kama”. It is a reliable and high-performance mechanisms, but they have their Achilles ‘ lie — backflow valve which keeps well enough in the system water during the period when Kasos does not work. As a result, the pipes creates air tubes that cause the water system in a kind of “embolism” — the pump ceases to swing, and to make him re-earn, we have to fill the system with water to avoid this, it is enough after irrigation to fix the hose on the hill or just put it in a container of water.
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