Key words: water pump, self-filling, water absorption When the water pump from the pool, if the use of self-filling water absorption, can make the suction pipe has been filled with water, the pump starts, eliminating the need for irrigation exhaust time, can be quickly put into operation to improve the pump start automation and reliability degree. Often used self-filling water absorption is the pump shaft elevation below the pool water level. This method is often used in basement buildings, layout, the pump room is set in the basement, the pool set in the basement next to the pump room or underground, as shown in Figure 1. This way of absorbing water, the working level of the water tank is higher than the elevation of the pump shaft, so that the water suction pipe is always filled with water, which can ensure the pump to start automatically and quickly. For buildings that do not have a basement, there are difficulties with the self-filling suction method described above. Because of this kind of construction, the pump house is usually arranged on the ground floor. If the pool is arranged beside the bottom pump house, especially the relatively large fire pool, it will occupy a large amount of ground floor area, and the construction unit generally will not agree. In this case, the pool is usually set outside the building and buried under the ground. This will lead to the pool water level below the pump shaft elevation, the pump can not be self-irrigation water absorption, this time, you can use the following ways to solve this problem. The first way is to install a suction valve at the end of the suction pipe of the pump, as shown in Figure 2. Suction valve is actually a check valve, which ensures that water can only enter the suction pipe from the pool and can not reverse, so if the suction pipe filled with water, although the pump shaft elevation above the working level of the pool, but due to suction bottom The role of the valve, the suction pipe water will not flow into the pool, the suction pipe has been filled with water, to ensure that the pump can automatically and quickly start. The reliability of this way of absorbing water is affected by the quality of the suction bottom valve. For example, the water in the suction pipe slowly flows into the pool due to the lax shut-off and water leakage, and there is no water in the suction pipe. As a result, Need artificial irrigation. The following way to absorb water to make up for this shortcoming. The second way is to use other water sources, as shown in Figure 3. It is based on the first type of water absorption, install a pipe in front of the pump outlet pipe check valve, and connect this pipe to the outdoor municipal water supply pipe or other external water supply to the water pipe in the pump to supplement the bottom valve Leaking water, so that the suction pipe filled with water. The reliability of this way of absorbing water is affected by the outdoor water source. Under the condition of long-term outdoor water stoppage, the water in the water-absorbing pipe may be leaked, so the water pump needs to be manually irrigated when it starts up. The third way is to improve the second way to absorb water, use the roof tank to pump water to the water pipe, as shown in Figure 4. This method is not subject to the impact of outdoor water stops, high reliability, suitable for buildings with roof tanks, roofless water tanks in the building, you can set up a small pump in the water tank to the pump suction pipe to replenish water. The fourth way is to set the pump before the suction tank, shown in Figure 5. In this way, a water suction tank needs to be set on the water suction pipe of the water pump. Before the first operation of the water pump, the water in the tank should be manually filled with water. After the first operation is stopped, the height of the water inlet pipe of the water suction tank is higher than the water level in the pipe. Therefore, the water tank can store a certain amount of water, and because of the suction tank outlet pipe (ie, the suction pipe of the water pump), the height of the water tank Below the surface of the water tube, it can ensure that the pump suction pipe full of water, after the pump and then run, the water tank was pumped water pump, tank negative pressure, the pool of water under the action of atmospheric pressure added to Suction tank, through the sump tank inside. Water continues to enter the pump, was the source of output. This kind of water absorption method has high safety and reliability, but a water suction tank needs to be set, and the larger the capacity of the water suction pipe is, the larger the volume of the water suction tank is, which not only increases the manufacturing cost but also occupies a certain space in the water pump room. The fifth way is to set the vacuum pump on the pump suction pipe. Before starting the pump, the vacuum pump should be started first, so that the water inside the pump suction pipe is filled with water first, so that the pump can start automatically and quickly. This water absorption method requires a complete automatic control system to ensure Vacuum pumps start prior to the pump, and the cost is high, reliability is affected by the automatic control system. It can be seen from the above analysis that the self-filling type water absorption method is safe and reliable. When the self-filling type water absorption method can not be adopted, the water absorption method of the water pump should be selected according to the actual conditions of the project so as to be safe, reliable and economical.