There are several submersible pumps , the motor line package with oil invasion and water intrusion is dry before use must read the instructions, can not make mistakes, long-term do not have, must use the impeller before the turn around , Otherwise it will be because the long-term card to burn and burn package. 　　 Before opening the pump, the suction tube and pump must be filled with liquid. After the pump is turned on, the impeller rotates at a high speed and the liquid rotates along with the blades. Under the action of centrifugal force, the liquid will fly out of the impeller and the liquid will gradually become slower in the diffusion chamber of the pump housing, and the pressure gradually increases. Export, discharge pipe outflow. At this time, at the center of the vane, the liquid is thrown around to form a vacuum low-pressure area free of air and liquid, and the liquid in the liquid pool flows into the pump through the suction pipe by the atmospheric pressure of the pool surface, Continuously sucked up from the liquid pool and continuously from the discharge pipe outflow. 　　 For the use of high-lift submersible pumps, we mainly drainage, then the amount of water and water flow control, I believe many do not know the solution, then the submersible pump water flow control of the various adjustment methods to explain. 　　 1. Speed ​​adjustment. Change submersible pump speed, can make the performance of the pump change, so that the pump operating conditions point change, this method is called variable speed mediation. 　　 2. Diameter adjustment. Impeller after turning, the performance of the pump will be in accordance with certain laws change, so that the pump operating conditions change. We change the way the turning impeller pump working point, called the adjustable diameter. 　　 Variable angle adjustment. Change the blade installation angle can make the performance of the pump change, so as to achieve the purpose of changing the submersible pump operating point. This way of changing the working point is called the variable angle adjustment of the pump. 　　 4. Throttling regulation. For the outlet pipe installation of the valve device of the pump , the gate valve closed hours, adding some local resistance in the pipeline, the pipeline characteristic curve steep, the working point along the QH curve of the pump to move up and down. The smaller the gate valve is closed, the greater the increased resistance and the smaller the flow rate becomes. This by closing the gate valve to change the pump operating point, known as throttling or variable valve control. 　　 When the gate valve is closed, the local head loss of the pipeline increases, the piping system characteristic curve moves to the upper left and the pump working point also moves to the upper left. Gate valve closed the smaller, the greater the loss of local head, the smaller the flow rate. This shows that the throttle adjustment not only increases the local head loss, but also reduces the amount of water, it is not economical. However, due to its simplicity and ease of use, small pumps and pumps are used more in performance tests.