First, the automatic water supply device technology status and characteristics At present, the micro-sprinkler irrigation system used in pressure tank automatic water supply device, which uses the pump type is generally self-priming centrifugal pumps, deep well pumps and submersible pumps. Self-priming centrifugal pump is characterized by compact structure, simple operation, but the manufacturing process is complex, long self-priming, low efficiency, high operating costs; deep well pump and submersible pump although has a certain lift, but the effluent flow is small, especially Deep well pump, using long drive shaft, consume more steel, expensive, difficult installation and maintenance. In this paper, the centrifugal pump automatic water supply device is to solve the pump in the automatic water supply system deficiencies, which is characterized by less investment, high efficiency, quick start, high head high flow, low operating costs, easy maintenance and repair machinery. Second, the working principle Common centrifugal pump working principle is to use the principle of centrifugal force to work, that is, before the pump and inlet pipe filled with water, or use the vacuum pump to start again. Ordinary centrifugal pump automatic water supply device works are: the use of hand-pressure well pump and pump suction pipe air once cleared, through the check valve and gate valve and other facilities always keep the pump and pump suction pipe is full of water, at any time Can be activated. Third, the installation process and technical requirements 1. Installation process Well on the ground tube, the first installation of the bottom valve connected to the well pipe tee, in turn above the well pipe to install the valve and hand kill wellhead; followed by connecting the pump and check valve Thirdly, connect the water supply pipe 9 and the water supply valve, install the electric pressure gauge on the pressure tank and install the power distribution facilities on the ground. 2. Technical Requirements (1) Bottom well valve installed on the ground. (2) Pressure tank outlet pipe elevation - pump outlet pipe elevation ≥ 0.5 m. (3) The water level in the pressure tank before the first water supply is higher than the water level in the water pump outlet pipe. Fourth, the technical analysis and analysis of benefits Technically, (1) the device compared with ordinary centrifugal pump to solve the problem of centrifugal pump starting irrigation or use of vacuum pump pumping process; (2) can be frequently started, easy to automate (4) Compared with self-priming centrifugal pumps, the advantages of using ordinary centrifugal pumps with high efficiency; (5) With the deep well pump and diving Pump compared to its large flow, head high. In terms of efficiency, (1) the plant solves the investment of manual or purchased vacuum pumps that start the irrigation several times in ordinary centrifugal pumps; (2) reduces the operating costs of investment in water source projects and other ancillary facilities; (3) facilitates maintenance and installation . Fifth, the scope of application For a certain size of water-saving irrigation district, rural water and urban water projects and industrial water district and other water sources can be applied to ordinary centrifugal pump automatic water supply device. Groundwater irrigation areas, underground pipe depth should not exceed 10 meters (including the pump house depth). VI Conclusion The use of ordinary centrifugal pumps improve performance, broaden the scope of application.