GP series of self-suction pump is designed according to the theory of vacuum self-suction. It can exhaust automatically the breathed air in the pipe so as to obtain the vacuum self-suction effect. So, it is widely used for water drawing from a normal pressure-type well, steel-pipe well or added pressure water supply to high building. When added with automatic device, the self-suction pump can supply water, or increase the pressure in an automatic way, just like the running water. The above series have many kinds of products and different appearances, so as to meet the various needs of customers.