1. the variable-speed control. Changing the speed of pump can bring about changes in pump performance, so that the operating point of the pump changes, this method is known as shift mediation.
2. variable size adjustment. After after turning the impeller, pump performance will change according to certain rules, so that the pump operating point changes. Our method of turning impeller change pump, called the variable size adjustment.
3. angle adjustment. Change the installation angle of the blade may cause the pump performance changes, so as to achieve the objective of changing submersible pump operating point. This change points is called a variable angle adjustment of the pump.
4. throttle control. For outlet pipe road, install a gate valve pump installation, turn the valve off hours, increase local resistance in the pipe, pipeline characteristics curve steepened its operating point moves along the Q-H of the pump curve up and to the left. Gate valve closed smaller, increases resistance to greater flow becomes smaller and smaller. This by turning down the gate valve to change the method of pump operating point, called a throttling valve or control.
When down the gate valve, the pipeline of local head loss increases, system characteristic curve moved up and to the left, pump moved up and to the left. Gate valve closed smaller, larger local head loss, less traffic. Thus throttling will not only increase local head loss, and reduced water was uneconomic. But because of its simple, small water pumps and water pump performance test applications.