self-priming pump
A self-priming pump, commonly used in the south, functions by exploiting the principle of water flow dynamics. It works by utilizing the momentum of water flow to draw it into the pump, with the impeller spinning the water from the riverbank up. When thrown into the water, this type of pump can extract water, provided there's sufficient flow velocity or a drop in elevation.
Due to its unique design, the self-priming pump boasts better sealing compared to regular centrifugal pumps. When the motor stops, water within the pump casing doesn't automatically drain, allowing it to maintain a negative pressure or vacuum when the motor restarts. This vacuum is utilized by atmospheric pressure to force water into the pump, from where it is then centrifugally lifted to higher levels. Consequently, the suction capacity of a self-priming pump is limited to about one atmospheric pressure, around 11 meters.
Unlike conventional centrifugal pumps, which require a pre-filled water column in the pump body and intake pipe to establish a vacuum before operation, a self-priming pump does not need such preparatory measures. The water is drawn into the pump directly due to the water pressure in the surroundings and the motor's ability to create a vacuum. This continuous cycle allows for uninterrupted water extraction without the need for preliminary filling. This is the essence of how self-priming pumps work.
