As the self-priming pump plays an increasingly important role in many fields, the research on such products has drawn more and more attention. Many users always have a question when using the product. Why do self-priming pumps add water every time? Next, we will analyze the reasons for this incident. Self-priming pump Self-priming pump can save some water, start again without irrigation. As for the suction stroke and the pump should be related to the NPSH margin. Self-priming process is by self-priming pump self-priming pump out of the water after the formation of a vacuum to the water pump to the inside, so in addition to the impeller immersed in the water pump, the commonly used self-priming pump products are open pump Must be filled with water to the pump, commonly known as filling pump, self-priming pump due to the larger pump inlet position at the inlet of the upper part of the pump with check valve only need to be . Self-priming pump irrigation methods are as follows: The first method is directly from the self-priming pump inlet or outlet to the self-priming pump inside the irrigation, this time should be noted that the self-priming pump outlet should be next to the exhaust valve Open the exhaust; there is a way that is self-priming pump air pre-extracted with a vacuum pump, to achieve a certain degree of vacuum and then start the self-priming pump this situation need to close the outlet pipe valve. In the pump industry, "diversion" refers specifically to "water for guidance". Because some pumps in the work, you must manually add water to make the pump within the formation of a closed environment, pump parts and then move to create a partial vacuum in order to allow external water pressure inside and outside the pressure at atmospheric pressure into the pump inlet to complete the water absorption action . For example, in the past, water pumps commonly used in rural areas had to be supplemented with water before the water in the wells could be sucked up. Suction level, with the pump power, flow, structure, etc. are related, but limited by the volume, power, the general self-priming suction miniature pump is not easy to do higher, because at most one of the atmospheric pressure on the water pressure The height of 10.3 meters (because of the atmospheric pressure ≈ 10.3 meters water pressure), so the maximum self-suction is about 10.3 meters. Self-priming pump in many areas to facilitate the use of people's work, it can well reduce the labor intensity of manpower, it not only improves people's work efficiency, while creating great value. Its lightweight and smart make it easy to install, repair, after years of development, these products have a very good market competitiveness, but also has a good application market and development prospects, I believe in the future, it will Become ace equipment pump.