Types Of Self-Priming Pumps

Self-priming pumps are classified by operating principle into the following categories: 1. Gas-liquid mixing type (including internal mixing and external mixing); 2. Water-ring wheel type; 3. Jet type (including liquid jet and gas jet). The operating process of gas-liquid mixing self-priming pumps is as follows: Due to the pump body's special structure, a certain amount of water remains in the casing after the pump stops. Upon restarting, the rotating impeller thoroughly mixes the air and water from the suction line and discharges the mixture into a gas-water separation chamber. Gas escapes from the upper part of the chamber, while water returns to the impeller to mix again with remaining air from the suction line; this cycle continues until all gas is evacuated from the pump and suction line, completing the self-priming process and enabling normal pumping. Water-ring wheel self-priming pumps house both a water-ring wheel and a pump impeller within a single casing, utilizing the water-ring wheel to expel gas and achieve self-priming. Once the pump is operating normally, the passage between the water-ring wheel and the impeller can be shut off via a valve, and the liquid within the water-ring wheel drained. Jet-type self-priming pumps consist of a combination of a centrifugal pump and a jet pump (or ejector); they rely on a jetting device to create a vacuum at the nozzle, thereby achieving suction.
Based on the type of prime mover, they are classified into electric motor-driven and diesel engine-driven self-priming pumps.
Based on the structure and operating characteristics used to achieve self-priming, they can be classified into internal sliding vane, external sliding vane, water-ring wheel, and other types. Transmission methods include direct coupling (including internal shaft arrangements) and belt drive. Inlet diameters range from 25 to 200 millimeters.