When the water pump sucks water from the pool, if the self filling suction mode is adopted, the suction pipe can be filled with water all the time. When the water pump starts, it saves the time of filling and exhausting, and can be put into operation quickly, which improves the automation and reliability of the pump startup.

The self filling suction method is often used to make the axis elevation of the pump lower than the working water level of the pool. This method is often used in buildings with basements. When arranging, the pump house is set in the basement, and the pool is set beside the pump house in the basement or outdoor underground. In this way, the working water level of the pool is higher than the elevation of the pump axis, so that the suction pipe is always full of water, which can ensure the automatic and rapid start-up of the pump.

For buildings without basement, it is difficult to adopt the above self irrigation water absorption method. Because of this kind of building, the water pump room is generally arranged on the ground floor. If a pool is set up beside the water pump room on the ground floor, especially the fire pool with large volume, it will occupy a large amount of ground floor area, and the construction unit will not agree with it.

In this case, the pool is usually set outside the building and buried under the ground. As a result, the working water level of the pool is lower than the elevation of the pump axis, and the water pump can not realize self filling suction. At this time, the following methods can be adopted to solve this problem.

The first method is to install suction bottom valve at the end of water pump suction pipe. The suction bottom valve is actually a kind of check valve, which ensures that the water flow can only enter the suction pipe from the pool, and can not flow backward. Therefore, if the suction pipe is full of water, although the elevation of the pump axis is higher than the working water level of the pool, the water in the suction pipe will not flow into the pool due to the function of the suction bottom valve, which can make the suction pipe full of water all the time and ensure that the pump can start automatically and quickly. The reliability of this water absorption method is affected by the quality of suction bottom valve. For example, if the valve is not closed tightly and leaks, the water in the suction pipe will flow into the pool slowly. After a long time, there will be no water in the suction pipe, resulting in manual irrigation when the pump is started.

The following water absorption methods can be used to make up for this deficiency.

The second way is to use other water sources. On the basis of the first method of water absorption, a pipeline is installed in front of the check valve of the water pump outlet pipe, and the pipe is connected to the outdoor municipal water supply pipe or other external water sources to supply water to the water pump suction pipe, to supplement the water leaked from the bottom valve, so as to make the suction pipe full of water. The reliability of this water absorption method is affected by the outdoor water source. When the outdoor water source is stopped for a long time, the water in the suction pipe may leak out, so it is necessary to inject water manually when the pump is started.

The third way is to improve the second way of water absorption, using roof water tank to replenish water into the pump suction pipe. This method is not affected by outdoor water supply interruption and has high reliability. It is suitable for buildings with roof water tank. For buildings without roof water tank, a small water tank can be set in the water pump room to supply water to the water pump suction pipe.

The fourth way is to set the suction tank in front of the pump. In this way, a suction tank should be set up on the suction pipe of the water pump. Before the first operation of the pump, the tank should be filled with water manually. After the first operation, because the height of the water inlet pipe of the suction tank is higher than that of the water surface in the pipe, the water in the tank will not flow back and enter the pool, so a certain amount of water can be stored in the suction tank Water, and because the height of the outlet pipe of the suction tank (i.e. the suction pipe of the water pump) is lower than the water surface height in the pipe, it can ensure that the suction pipe of the water pump is full of water. When the water pump runs again, the water in the water tank is pumped away by the pump, and the negative pressure appears in the tank. The water in the pool is added to the suction tank under the action of atmospheric pressure.

Water is constantly into the pump, is the source of output. This suction method is safe and reliable, but it needs to set up a suction tank, and the larger the volume of the suction pipe, the larger the volume of the suction tank, which not only increases the cost, but also takes up a certain space in the pump house.

The fifth way is to set up a vacuum pump on the suction pipe of the water pump. Before the pump is started, the vacuum pump is started first, so that the suction pipe of the water pump is filled with water to ensure the automatic and rapid start of the pump. This kind of water absorption needs perfect automatic control system to ensure

The vacuum pump starts earlier than the water pump, and the cost is high, and the reliability is affected by the automatic control system.

Through the above analysis, it can be seen that the self irrigation water absorption mode is safe and reliable. When the self irrigation water suction mode cannot be adopted, the water suction mode of the water pump should be selected according to the actual situation of the project, so as to achieve both safety, reliability and economic rationality.

Technology Department