The meaning of self-priming pump in mini pump

Now on the market there are all kinds of micro-pump | micro-circulation pump | micro-pump | high-pressure micro-pump | liquid sampling pump | small pump | self-priming pump | DC pump | diaphragm pump, whether self-priming function, mainly see the following two points : 1. self-absorption means: the pump suction pipe is the case of air, the use of negative pressure pump (vacuum), under the action of atmospheric pressure will be lower than the water pressure on the pump up, and then from the pump Drain end discharge. Before this process does not require additional water (water guide). Pumps with this capability are called self-priming pumps. 2. Some centrifugal or rotary vane pump in the water before, you must add water in the pump chamber to form a closed environment, and then pump operation to form a negative pressure, to achieve the purpose of water. For example, manual pumps were used in rural areas. Pumps that do not have self-priming capabilities require extra water before each suction, which is troublesome. 3. Suction level, with the pump power, flow, structure, etc. are related, but generally miniature pump self-priming suction is not easy to do higher, for example, a kind of miniature pump BSP27250S self-priming suction can reach 5 meters, even higher.